Broad forehead, hypertelorism, small chin, long philtrum, camptodactyly, and fetal finger pads are features of the following genetic overgrowth syndrome
Rationale:
Broad forehead, hypertelorism, small chin, long philtrum, camptodactyly, and fetal finger pads are features of Sotos syndrome.
Sotos syndrome is characterized by distinctive facial features including a broad forehead and hypertelorism, along with other traits like camptodactyly and fetal finger pads, which align with the described symptoms. This genetic overgrowth syndrome is known for its specific phenotypic manifestations that include both physical and cognitive elements.
A: Perlman syndrome features overgrowth and kidney issues, lacking the specific facial characteristics described in the question, making it distinct from Sotos syndrome.
C: Weaver syndrome also involves overgrowth but does not typically present with the combination of facial features and digit abnormalities outlined, setting it apart from Sotos syndrome.
D: Beals syndrome primarily affects connective tissue and is associated with limb abnormalities and other features, not aligning with the specific facial traits mentioned in the question.
Physical findings in Graves disease include all of the following EXCEPT
Rationale:
Cold intolerance is not a physical finding in Graves disease; instead, patients typically experience heat intolerance due to increased metabolism and sympathetic activity, leading to symptoms such as sweating and warmth.
A: motor hyperactivity Increased activity levels are common in Graves disease, as heightened thyroid hormones stimulate the nervous system, resulting in symptoms such as restlessness and excessive energy.
C: tremor Tremors are a typical symptom of Graves disease, arising from heightened thyroid hormone levels affecting the nervous system, causing involuntary shaking, especially in the hands.
D: weight loss Weight loss frequently occurs in Graves disease due to increased metabolism and energy expenditure, as the body burns calories at an accelerated rate driven by excess thyroid hormones.
Cushing syndrome in children has many causes, either exogenous or endogenous. Of the following, the LEAST likely endogenous cause in children is
Rationale:
Cushing syndrome in children has many causes, either exogenous or endogenous. Of the following, the LEAST likely endogenous cause in children is nodular adrenal hyperplasia.
Nodular adrenal hyperplasia is typically associated with adult cases of Cushing syndrome and involves the excessive growth of adrenal tissue. In children, less prevalent causes like adrenal adenoma, carcinoma, and ACTH-secreting pituitary microadenomas are more common, making this condition the least likely to cause Cushing syndrome in the pediatric population.
A: adrenal adenoma This condition can cause excess cortisol production in children, leading to Cushing syndrome, as it represents a direct tumor of the adrenal gland influencing hormone levels.
B: adrenal carcinoma A malignant adrenal tumor in children can significantly raise cortisol levels, contributing to Cushing syndrome; its aggressive nature makes it a recognizable endogenous cause in pediatric cases.
D: ACTH-secreting pituitary microadenoma These tumors produce excess adrenocorticotropic hormone, stimulating cortisol production in the adrenal glands and serving as a notable cause of Cushing syndrome in children.
Inborn errors of metabolism (IEM) are hereditary biochemical disorders caused by single-gene mutations that result in alteration of
Rationale:
Inborn errors of metabolism (IEM) are hereditary biochemical disorders caused by single-gene mutations that result in alteration of primary protein structure or the amount of protein synthesized.
This option is accurate as IEM specifically involves mutations affecting enzymes and proteins essential for metabolic pathways, leading to disrupted biochemical processes and the accumulation of toxic substances or deficiency in vital compounds.
A: chromosomal number or structure This choice focuses on chromosomal abnormalities, which are not the primary cause of IEM, as these disorders arise from specific gene mutations rather than broader chromosomal alterations.
B: mitochondrial synthesis or function While mitochondrial dysfunction can lead to metabolic issues, IEMs are primarily linked to defects in nuclear genes affecting protein synthesis, not directly related to mitochondrial processes.
C: primary fat structure or the amount of fat synthesized This option pertains to lipid metabolism, yet IEMs primarily involve the synthesis and function of proteins, which are crucial for a wide range of metabolic activities.
Matching: For each inborn error of amino acid metabolism, select the correct urine odor - Glutaric acidemia (type II)
Rationale:
C: Sweaty. The odor associated with Glutaric acidemia (type II) is characterized by a distinct sweaty smell, which is a hallmark of the metabolic disturbance linked to this condition.
A: Cabbage. This odor typically relates to different metabolic disorders, such as methionine metabolism issues, and does not correlate with the specific symptoms of Glutaric acidemia (type II).
B: Hoplike. The hoplike smell is often associated with other metabolic conditions, such as isovaleric acidemia, rather than Glutaric acidemia (type II), which has a different odor profile.
Treatment is initiated with high-dose vitamin B6 but no response is observed. The most likely explanation is
Rationale:
A: Folate deficiency is the most likely explanation for no response to high-dose vitamin B6 treatment, as it indicates an underlying deficiency that may prevent effective metabolism of vitamin B6.
B: Malabsorption could hinder nutrient uptake, but it does not specifically explain the absence of response to vitamin B6, which should still have some effect if adequately absorbed.
C: Gastric hypersecretion primarily affects the stomach's acidity and does not directly relate to the metabolism or utilization of vitamin B6, making this option less relevant to the scenario.
D: Vitamin B1 deficiency might cause neurological symptoms, yet it does not account for the lack of response to vitamin B6, as each vitamin functions independently in different metabolic pathways.
A 5-year-old child with recurrent attacks of ketotic hypoglycemia. Of the following, the BEST advice to the parents during any intercurrent illness is to
Rationale:
A high-carbohydrate diet is the best advice for managing a 5-year-old child with recurrent ketotic hypoglycemia during intercurrent illnesses. This approach helps to prevent hypoglycemia by providing readily available glucose, effectively addressing the child's metabolic needs during stressful periods.
A: Administrate a high-protein diet. High protein intake may not adequately prevent hypoglycemia, as it does not provide the quick energy required during illness, potentially exacerbating the child's condition.
B: Test the child's urine for ketones. While monitoring ketones can be informative, it does not directly influence immediate management or treatment strategies for preventing hypoglycemic episodes during illness.
D: Do frequent monitoring of blood sugar. Although monitoring is important, it does not actively prevent hypoglycemia. Without appropriate dietary intervention, mere monitoring may lead to missed opportunities for effective management.
A 2-year-old boy presented with failure to thrive, regression of developmental milestone, and difficult to contact with surroundings. On examination, there are hepatosplenomegaly and moderate lymphadenopathy. Of the following, the MOST likely diagnosis is
Rationale:
Niemann-Pick disease is the most likely diagnosis, characterized by failure to thrive, developmental regression, hepatosplenomegaly, and lymphadenopathy. These symptoms align with the sphingomyelin accumulation seen in this lysosomal storage disorder.
A: Gaucher disease presents with splenomegaly and bone pain, but developmental regression is not as prominent as in Niemann-Pick disease, making it less likely in this scenario.
B: Sandhoff disease involves neurological deterioration and cherry-red spots but typically lacks significant hepatosplenomegaly and lymphadenopathy, distinguishing it from the symptoms presented here.
C: Tay-Sachs disease primarily affects neurological development and does not commonly present with hepatosplenomegaly or lymphadenopathy, which are crucial indicators in this case.
The following features suggest constitutional delay as a cause of short stature EXCEPT
Rationale:
Constitutional delay typically does not correlate with a period of poorest growth occurring between 18 and 30 months, as this stage is often linked to various growth patterns.
A: no signs or symptoms of systemic disease. Absence of systemic disease indicates that short stature may not stem from underlying health issues, supporting a diagnosis of constitutional delay.
B: bone age delayed beyond the height age. A significant discrepancy between bone age and height age suggests a developmental delay, which typically aligns with constitutional growth delays.
D: parental or sibling history of delayed development. Family history of delayed development is a common indicator of genetic factors influencing growth, thus not pointing specifically to constitutional delay as the sole cause.
A 7-month-old girl presented with recurrent chest infection, chocking during feeding, large protruded tongue, persistent head lag, and hepatomegaly. Chest X-ray showed cardiomegaly. All the following are beneficial in the treatment of this patient EXCEPT
Rationale:
Exercise therapy is not beneficial for this patient. Given her symptoms indicating severe cardiopulmonary compromise, exercise could exacerbate her condition rather than improve her overall health and wellbeing.
B: high-protein diet. A high-protein diet supports growth and development, which is crucial for this patient who presents with feeding difficulties and potential malnutrition due to her medical condition.
C: cardiac transplantation. Cardiac transplantation is a viable option for patients with significant heart failure, and in this case, it may be necessary to address the underlying cardiomegaly effectively.
D: nocturnal ventilatory support. Nocturnal ventilatory support can improve respiratory function, especially in patients with compromised lung capacity and recurrent infections, helping to alleviate respiratory distress during sleep.
Holoprosencephaly is associated with all of the following EXCEPT
Rationale:
Holoprosencephaly is associated with congenital malformations such as cyclopia, pituitary hypoplasia, and cebocephaly, but not with congenital toxoplasmosis, which is unrelated to this brain development disorder.
A: cyclopia This condition, characterized by a single eye, is a well-documented manifestation of holoprosencephaly, resulting from improper brain division during early embryonic development.
B: pituitary hypoplasia This condition refers to an underdeveloped pituitary gland, often seen in holoprosencephaly cases, as both conditions stem from similar embryonic disruptions affecting midline structures.
C: cebocephaly Cebocephaly, which features a combination of facial anomalies, is also linked to holoprosencephaly due to the shared developmental pathways that influence midline facial and brain structures.
Mucopolysaccharidoses (MPS) affect many solid organs, the brain is spared in
Rationale:
MPS VI (Maroteaux-Lamy) is the type of mucopolysaccharidosis that affects many solid organs while sparing the brain.
This condition primarily impacts connective tissues and skeletal development, leading to significant organ involvement without neurodegeneration. Unlike other MPS types, MPS VI maintains cognitive function, allowing for normal brain development despite the systemic disease effects on other organs.
A: MPS I (Hurler) Involves severe neurological impairment and cognitive decline, affecting the brain significantly alongside various solid organs.
B: MPS II (Hunter) Also causes intellectual disability and neurological symptoms, indicating brain involvement while impacting other body systems.
C: MPS III (Sanfilippo) Primarily leads to progressive neurodegeneration and cognitive decline, severely affecting brain function and development, alongside organ issues.
You suspect a metabolic problem in a 30-day-old girl presented with poor feeding, vomiting, lethargy, and convulsion. Previous sibling died with the same condition. Serum ammonia, pH, HCO3, and anion gap are normal. Of the following, the MOST likely diagnosis is
Rationale:
Aminoacidopathy. The clinical presentation of poor feeding, vomiting, lethargy, and convulsions, combined with a history of a sibling's similar condition, suggests a genetic metabolic disorder involving amino acids, aligning with aminoacidopathy.
A: Porphyria. Symptoms of porphyria typically involve skin sensitivity and neurological disturbances, which are not consistent with the presenting signs in this case, indicating a different metabolic issue.
B: Galactosemia. While galactosemia can cause feeding difficulties and lethargy, it usually presents with symptoms like jaundice and cataracts, which are absent in this patient's presentation.
C: Organic acidemia. Although organic acidemias can lead to metabolic crises, the normal levels of ammonia, pH, and HCO3 suggest that an organic acid disorder is less likely in this scenario.
During a routine physical examination, a solitary thyroid nodule is palpated in asymptomatic 10-year-old child. Of the following, the MOST likely cause is
Rationale:
Thyroid adenoma is the most likely cause of a solitary thyroid nodule in an asymptomatic 10-year-old child. This benign tumor is commonly found in children and presents as a non-functional nodule without accompanying symptoms.
A: Thyroid carcinoma presents with additional symptoms or concerning features, which are not evident in this asymptomatic child, making it an unlikely diagnosis.
C: A thyroid abscess typically involves infection and would present with systemic symptoms such as fever or pain, which are absent in this case.
D: Thyroid cysts are fluid-filled and may not typically present as solitary nodules; they are more commonly found as part of a multi-nodular goiter, making them less likely here.
A 16-year-old boy has delayed puberty; he doesn’t develop secondary sexual characteristics; he has a normal stature according to his chronological age. Examination reveals an upper-to-lower segment ratio of 0.8 (normal ratio is more than 0.9). Of the following, the MOST important test to confirm diagnosis is
Rationale:
Plasma gonadotropins are the most important test to confirm the diagnosis of delayed puberty in this boy. Elevated or low levels will indicate whether there is a primary or secondary sexual development issue, guiding further management.
B: Growth hormone stimulation test assesses growth hormone deficiency, which is not indicated in this scenario focused on delayed sexual maturation rather than growth abnormalities.
C: Serum prolactin measures prolactin levels, which are not directly related to the assessment of puberty timing or secondary sexual characteristic development in this case.
D: Brain MRI evaluates structural brain issues that could affect hormonal regulation; however, it is not the first-line test for diagnosing delayed puberty when gonadotropin levels are crucial.
Matching: Lipidosis - GM1-gangliosidosis
Rationale:
Lipidosis is associated with GM1-gangliosidosis, which presents both cherry red spots in the eyes and hepatosplenomegaly, making option C the accurate match for these conditions.
A: Cherry red spot This symptom occurs in GM1-gangliosidosis but does not encompass the complete clinical picture, as it neglects the significant enlargement of the liver and spleen present in this disorder.
B: Hepatosplenomegaly While hepatosplenomegaly is also a feature of GM1-gangliosidosis, this option fails to include the cherry red spot, which is another key clinical manifestation of the condition.
D: Neither A nor B This choice overlooks the fact that both symptoms are characteristic of GM1-gangliosidosis, failing to recognize the essential link between these clinical signs and the disease.
Type I diabetes mellitus is most often associated with
Rationale:
Type I diabetes mellitus is most often associated with antibodies to glutamic acid dehydrogenase. This association highlights the autoimmune nature of Type I diabetes, where the body's immune system mistakenly targets pancreatic cells, leading to insulin deficiency and elevated blood glucose levels. The presence of these antibodies serves as a crucial biomarker in diagnosing the condition.
A: mumps infection Mumps may contribute to various complications, but it lacks a direct and specific link to the autoimmune process underlying Type I diabetes mellitus, making it an unlikely association.
B: coxsackievirus While coxsackievirus has been studied for its potential role in triggering Type I diabetes, its connection is less definitive compared to the established relationship with antibodies to glutamic acid dehydrogenase.
D: cow's milk Although some studies suggest a possible link between cow's milk proteins and Type I diabetes onset, this association is not as well-supported as the presence of specific antibodies in diagnosing the disease.
All the following are clinical features of acute intermittent porphyria EXCEPT
Rationale:
D. Acute intermittent porphyria is characterized by symptoms such as abdominal pain, neuropathy, and tachycardia, while cutaneous photosensitivity is not a typical clinical feature associated with this condition.
A: neuropathy Neuropathy is a common manifestation in acute intermittent porphyria, often presenting as pain or weakness due to nerve involvement during acute attacks of the disorder.
B: tachycardia Tachycardia frequently occurs in acute intermittent porphyria, resulting from autonomic instability and the body's response to pain and stress during acute episodes of the disease.
C: abdominal pain Abdominal pain is a hallmark symptom of acute intermittent porphyria, often severe and associated with gastrointestinal complications during acute attacks, marking it as a key clinical feature.
The parents of a 2-year-old boy with Tay-Sachs disease ask you about the availability of prenatal testing in their pregnancy. When counseling this couple about prenatal diagnosis, it would be most appropriate to include which one of the following statements:
Rationale:
Testing can be performed on chorionic villus cells obtained as early as 10 weeks of pregnancy. This option accurately reflects the timeline for performing prenatal testing, allowing early diagnosis of Tay-Sachs disease, which is critical for informed decision-making and potential intervention options for the parents.
B: Results of prenatal diagnosis testing for Tay-Sachs disease are considered investigational. This statement misrepresents the established protocols and reliability of the testing methods available for identifying Tay-Sachs disease during pregnancy.
C: Testing is only possible if the parents' mutations in the hexosaminidase gene are known. This assertion overlooks the fact that prenatal testing can be conducted without prior knowledge of parental mutations, using general testing methods.
D: The risk that they could have a similarly affected child in their next pregnancy is no greater than that of any other couple. This option inaccurately implies that genetic risk factors are irrelevant, neglecting the specific inheritance patterns of Tay-Sachs disease in carrier parents.
High-dose glucocorticoids (the equivalent of >10 times physiologic cortisol secretion) can be administered without requiring a subsequent tapering for
Rationale:
High-dose glucocorticoids can be administered for 7 days without requiring a subsequent tapering.
Administering glucocorticoids for 7 days allows the body to manage stress without significant suppression of the hypothalamic-pituitary-adrenal (HPA) axis, minimizing withdrawal symptoms upon discontinuation.
A: 5 day A duration of 5 days is insufficient for high-dose glucocorticoids to stabilize the body's response, potentially leading to abrupt withdrawal effects.
C: 10 day Extending treatment to 10 days increases the risk of HPA axis suppression, necessitating a taper to avoid adrenal insufficiency upon cessation.
D: 14 day A 14-day course raises significant concerns regarding prolonged glucocorticoid effects, requiring tapering to prevent complications associated with prolonged high-dose exposure.
The normal level of serum thyroid-stimulating hormone in first week of term infants is up to
Rationale:
Up to 27.0 mIU/L.
The normal serum thyroid-stimulating hormone level in infants during the first week of life can rise significantly, reaching levels as high as 27.0 mIU/L, reflecting the physiological adaptations post-birth and the need for thyroid function assessment during this critical period.
A: 4.4 mIU/L This value is significantly lower than the normal range for first-week term infants, indicating an insufficient thyroid-stimulating hormone level for proper metabolic function.
B: 9.5 mIU/L While this level is above typical adult ranges, it does not meet the higher threshold established for newborns during their initial week, thus underrepresenting normal physiology.
C: 13.6 mIU/L This measurement, although elevated, still falls short of the maximum expected levels for first-week infants, indicating that it does not encompass the full spectrum of normal thyroid-stimulating hormone variations.
Parathyroid crisis is manifested by the following EXCEPT
Rationale:
Parathyroid crisis is manifested by the following EXCEPT progressive polyuria.
In the context of parathyroid crisis, high serum calcium levels lead to symptoms such as stupor and azotemia, while polyuria is not a recognized manifestation of this condition, making it the exception.
A: serum calcium levels >15 mg/dL High serum calcium is a hallmark of parathyroid crisis, leading to severe physiological disturbances, including lethargy and confusion, indicating a critical condition.
C: azotemia Elevated nitrogen waste products in the blood, or azotemia, commonly occurs due to kidney dysfunction associated with hypercalcemia, which is a significant feature of parathyroid crisis.
D: stupor Stupor indicates altered mental status and is a direct consequence of elevated serum calcium levels, commonly observed in patients experiencing a parathyroid crisis, highlighting its severity.
A 9-year-old boy admitted to the hospital because of fracture of left femur due to a minor trauma. Past history revealed recurrent attacks of epistaxis and intermittent generalized bone pain. On examination, there is massive splenomegaly. Of the following, the MOST appropriate practical treatment of this disease is
Rationale:
Enzyme replacement is the most appropriate practical treatment for this disease. Given the boy's symptoms, including splenomegaly and bone pain, enzyme replacement addresses the underlying metabolic disorder effectively, alleviating symptoms and improving his quality of life.
A: Gene therapy This option targets genetic alterations, which is not suitable for this patient's condition, as enzyme deficiencies require direct replacement of the missing enzyme rather than altering genes.
B: Liver transplantation While it may treat some metabolic disorders, this boy's symptoms relate to enzyme deficiency, which would not resolve through liver transplantation, making it an inappropriate choice.
D: Substrate reduction agents Though these can reduce harmful metabolites, they do not directly replace the deficient enzyme. This patient's condition demands enzyme replacement for effective management of symptoms and underlying issues.
Matching: Hemizygotic male has complete syndrome
Rationale:
D: Nettleship full type ocular albinism is characterized by complete absence of pigment in the eyes, skin, and hair, reflecting the hemizygotic male phenotype and its associated syndromic features.
A: Chédiak-Higashi syndrome involves immunological deficiencies and neurological complications, which do not specifically relate to the complete syndrome presentation observed in hemizygotic males.
B: Hermansky-Pudlak syndrome includes albinism along with bleeding disorders, lacking the distinctive ocular manifestations required for a complete syndrome in hemizygotic males.
C: Waardenburg syndrome primarily affects pigmentation and hearing, presenting with incomplete features that do not fulfill the complete syndrome criteria for hemizygotic males.
Thyroid disorders consist of a variety of diseases that require different treatment according to the cause. Of the following, the thyroid disorder that does not require treatment is
Rationale:
D: Congenital thyroxine-binding globulin deficiency does not require treatment as it typically does not affect thyroid hormone levels or function, allowing for normal metabolic processes without intervention.
A: Congenital hypothyroidism necessitates treatment to prevent developmental delays and other health issues due to insufficient thyroid hormone production from birth.
B: Endemic cretinism demands treatment to address severe cognitive impairments and physical disabilities resulting from iodine deficiency affecting thyroid function.
C: Hashimoto thyroiditis requires management to mitigate symptoms and prevent complications arising from chronic inflammation and hormone imbalance in the thyroid gland.
Patients with autoimmune Addison disease must be closely observed for the development of other autoimmune disorders. Of the following, the MOST commonly associated disorder in children is
Rationale:
Patients with autoimmune Addison disease must be closely observed for the development of other autoimmune disorders, with type 1 diabetes mellitus being the most commonly associated disorder in children.
Type 1 diabetes mellitus frequently co-occurs with autoimmune Addison disease due to shared genetic and immunological factors, making it a significant concern in pediatric patients with this condition.
A: alopecia Alopecia does not have a strong association with Addison's disease in children, making it a less relevant concern compared to other autoimmune disorders.
B: vitiligo While vitiligo can accompany autoimmune disorders, it is less commonly linked with Addison's disease in the pediatric population compared to type 1 diabetes.
C: chronic active hepatitis Chronic active hepatitis is not typically associated with Addison's disease and does not present as a prevalent concern among children with this condition.
Nocturnal enuresis is best described as
Rationale:
Nocturnal enuresis is best described as involuntary loss of urine during sleep. This condition specifically occurs at night while the individual is asleep, differentiating it from other forms of urinary incontinence that may happen during waking hours.
A: Voluntary loss of urine during sleep. This option contradicts the definition of nocturnal enuresis, which is characterized by involuntary, not voluntary, loss of urine during sleep.
C: Involuntary loss of urine during the day. This description applies to daytime urinary incontinence, which is distinct from nocturnal enuresis that specifically pertains to nighttime occurrences.
D: Voluntary loss of urine during the day. This choice misrepresents the nature of enuresis, as it refers to voluntary control rather than the involuntary aspect associated with nocturnal enuresis.
A 14-month-old male of Northern European ancestry experienced an upper respiratory tract infection and anorexia. On the second day of the illness, he began to vomit, and by that evening he was unresponsive. On the way to the hospital, he had a generalized seizure lasting 10 minutes. At the hospital, he had a blood glucose of 10 mg/dL; his urinalysis showed no ketones. Liver function tests, anion gap, and serum ammonia were all normal. The most likely diagnosis is
Rationale:
Medium-chain acyl CoA dehydrogenase deficiency is the most likely diagnosis. The child’s hypoglycemia, lack of ketosis, and presentation after infection suggest an inborn error of metabolism affecting fatty acid oxidation, consistent with this condition.
B: maple syrup urine disease. This disorder typically presents with specific neurological symptoms and distinct urine characteristics, including a maple syrup odor, which are not evident in this case.
C: glutaric aciduria type I. This condition usually involves metabolic crises associated with certain infections and can lead to neurological decline, but the presented symptoms and lab results do not support this diagnosis.
D: glutamate formiminotransferase deficiency. While this deficiency affects amino acid metabolism, the acute presentation with hypoglycemia and lack of ketones aligns more closely with fatty acid oxidation disorders than with this condition.
In mucopolysaccharidosis, disproportionate severe CNS involvement with mild physical features is unique to
Rationale:
Disproportionate severe CNS involvement with mild physical features is unique to Sanfilippo disease. This condition primarily affects cognitive function while typically exhibiting less pronounced skeletal abnormalities, distinguishing it significantly from other mucopolysaccharidoses that present with more severe physical manifestations.
A: Scheie disease exhibits mild symptoms, primarily affecting physical growth rather than causing marked CNS involvement, which differentiates it from the characteristics of Sanfilippo disease.
B: Hurler disease presents with significant physical features and severe CNS involvement, contrasting sharply with the milder physical traits seen in Sanfilippo disease.
C: Hunter disease involves notable physical manifestations and can also affect the CNS but does not display the same disproportionate severity seen in Sanfilippo disease.
A 2-year-old boy presented with growth retardation, hepatomegaly, and recurrent attacks of hypoglycemia; biochemical study reveals elevated blood lactate, triglyceride, and uric acid levels. All the following are complications of this disease EXCEPT
Rationale:
Growth retardation, hepatomegaly, and recurrent hypoglycemia indicate a glycogen storage disease, commonly leading to complications like pancreatitis, renal failure, and hepatic adenoma. Cardiomyopathy is not typically associated with this condition.
A: pancreatitis This complication arises due to increased triglyceride levels and metabolic disturbances common in glycogen storage diseases, making it a relevant concern for affected individuals.
B: renal failure Glycogen accumulation can lead to kidney damage, resulting in renal failure, which is a recognized complication in patients suffering from the disease.
D: hepatic adenoma The disease frequently causes liver enlargement and dysfunction, leading to the development of hepatic adenomas, thus making it a significant complication in affected patients.
Broad forehead, hypertelorism, small chin, long philtrum, camptodactyly, and fetal finger pads are features of the following genetic overgrowth syndrome
Rationale:
Broad forehead, hypertelorism, small chin, long philtrum, camptodactyly, and fetal finger pads are features of Sotos syndrome.
Sotos syndrome is characterized by overgrowth and distinctive facial features, including a broad forehead and hypertelorism. The presence of camptodactyly and fetal finger pads further confirms this genetic condition, emphasizing its unique clinical profile. These features collectively indicate the presence of Sotos syndrome in affected individuals.
A: Perlman syndrome involves overgrowth and kidney abnormalities but lacks the specific facial features described, making it an incorrect choice.
C: Weaver syndrome includes overgrowth and distinct facial characteristics but does not specifically list the features mentioned in the question as defining traits.
D: Beals syndrome primarily affects connective tissue and presents with different physical manifestations, such as skeletal abnormalities, which do not align with the features given.
Physical findings in Graves disease include all of the following EXCEPT
Rationale:
Cold intolerance is not a physical finding in Graves disease, which typically presents with symptoms like hyperactivity, tremors, and weight loss due to increased metabolism from thyroid hormone excess.
A: motor hyperactivity Increased activity levels are characteristic of Graves disease, reflecting the heightened metabolic state caused by excess thyroid hormones stimulating the nervous system.
C: tremor Tremors are commonly associated with Graves disease as a result of elevated sympathetic nervous system activity, which manifests through physical signs such as shaking.
D: weight loss Weight loss often occurs in Graves disease due to hypermetabolism and increased energy expenditure, making it a typical symptom rather than an exception.
Cushing syndrome in children has many causes, either exogenous or endogenous. Of the following, the LEAST likely endogenous cause in children is
Rationale:
Cushing syndrome in children is least likely caused by nodular adrenal hyperplasia. This condition is rare in pediatric patients compared to the other listed causes, which are more frequently associated with endogenous Cushing syndrome.
A: adrenal adenoma This condition commonly leads to excess cortisol production and is a well-documented cause of Cushing syndrome in children, making it a probable endogenous source.
B: adrenal carcinoma This aggressive form of cancer is known to cause significant overproduction of cortisol, frequently contributing to the development of Cushing syndrome in pediatric cases.
D: ACTH-secreting pituitary microadenoma Such tumors are a common endogenous source of Cushing syndrome, effectively stimulating cortisol production through excessive ACTH secretion in children.
Inborn errors of metabolism (IEM) are hereditary biochemical disorders caused by single-gene mutations that result in alteration of
Rationale:
Inborn errors of metabolism (IEM) primarily disrupt the primary protein structure or the amount of protein synthesized, leading to various metabolic dysfunctions due to enzyme deficiencies linked to single-gene mutations.
A: chromosomal number or structure Alterations in chromosomal number or structure pertain to chromosomal abnormalities, not the specific gene mutations associated with IEMs affecting metabolic pathways.
B: mitochondrial synthesis or function Mitochondrial dysfunction relates to energy production issues rather than the direct impact on metabolism from single-gene mutations seen in IEMs.
C: primary fat structure or the amount of fat synthesized While fat metabolism disorders exist, IEMs predominantly involve protein synthesis alterations due to genetic mutations affecting specific enzymes and metabolic pathways.
Matching: For each inborn error of amino acid metabolism, select the correct urine odor - Glutaric acidemia (type II)
Rationale:
Sweaty. Glutaric acidemia (type II) is characterized by a distinctive odor in the urine, which often resembles that of sweat due to the accumulation of organic acids, specifically glutaric acid.
A: Cabbage. This odor is typically associated with other conditions, such as cystathionine beta-synthase deficiency, and does not apply to glutaric acidemia type II.
B: Hoplike. The hoplike odor is indicative of specific metabolic disorders, such as isovaleric acidemia, and does not correlate with the symptoms of glutaric acidemia type II.
Treatment is initiated with high-dose vitamin B6 but no response is observed. The most likely explanation is
Rationale:
High-dose vitamin B6 treatment without response suggests a folate deficiency. Folate is essential for numerous metabolic processes, and its insufficiency can impede the effectiveness of vitamin B6 treatment, leading to no observed improvement.
B: malabsorption Malabsorption typically indicates issues with nutrient uptake, but vitamin B6 would still show some effect if administered in high doses regardless of absorption problems.
C: gastric hypersecretion Excessive gastric secretion might affect digestion, yet it does not directly relate to the effectiveness of vitamin B6, which functions independently of gastric acid levels.
D: vitamin B1 deficiency While vitamin B1 deficiency can lead to several health issues, it does not specifically account for the lack of response to vitamin B6 treatment in this context.
A 5-year-old child with recurrent attacks of ketotic hypoglycemia. Of the following, the BEST advice to the parents during any intercurrent illness is to
Rationale:
A high-carbohydrate diet should be administered during any intercurrent illness. This dietary approach helps prevent hypoglycemia by providing readily available glucose, which is crucial for maintaining energy levels and metabolic stability in a child prone to ketotic hypoglycemia.
A: Administrate a high-protein diet. Protein intake does not effectively address the immediate energy needs during illness, potentially exacerbating hypoglycemia rather than providing necessary glucose for the child.
B: Test the child's urine for ketones. While monitoring ketones is beneficial, it does not offer a proactive solution to manage hypoglycemia during illness, focusing instead on a reactive measure.
D: Do frequent monitoring of blood sugar. Monitoring blood sugar levels is essential but insufficient on its own; proactive dietary adjustments are necessary to prevent hypoglycemic episodes during illness.
A 2-year-old boy presented with failure to thrive, regression of developmental milestone, and difficult to contact with surroundings. On examination, there are hepatosplenomegaly and moderate lymphadenopathy. Of the following, the MOST likely diagnosis is
Rationale:
Niemann-Pick disease. The symptoms of failure to thrive, developmental regression, hepatosplenomegaly, and lymphadenopathy align closely with Niemann-Pick disease, a lysosomal storage disorder characterized by lipid accumulation affecting multiple organ systems, particularly in young children.
A: Gaucher disease. This condition typically presents with bone pain, anemia, and splenomegaly, but not the pronounced neurological symptoms and developmental regression seen in this case.
B: Sandhoff disease. Although it involves severe neurological impairment, it usually manifests with more pronounced cognitive decline and does not primarily feature hepatosplenomegaly and lymphadenopathy as prominent symptoms.
C: Tay-Sachs disease. Primarily affecting neurological function with a characteristic cherry-red spot in the eye, it does not present with hepatosplenomegaly or lymphadenopathy, differentiating it from the presented case.
The following features suggest constitutional delay as a cause of short stature EXCEPT
Rationale:
Constitutional delay as a cause of short stature does not typically correspond with a period of poorest growth between 18 and 30 months, as this is usually earlier in childhood.
A: no signs or symptoms of systemic disease. The absence of systemic disease indicates that growth issues are likely due to constitutional factors rather than underlying health conditions.
B: bone age delayed beyond the height age. A delayed bone age relative to height age suggests that growth is still possible, aligning with the characteristics of constitutional delay.
D: parental or sibling history of delayed development. A family history of delayed development supports the likelihood of genetic or familial factors influencing growth patterns, distinguishing it from constitutional delays.
A 7-month-old girl presented with recurrent chest infection, chocking during feeding, large protruded tongue, persistent head lag, and hepatomegaly. Chest X-ray showed cardiomegaly. All the following are beneficial in the treatment of this patient EXCEPT
Rationale:
Exercise therapy is not beneficial for this patient. Given her symptoms of cardiomegaly and other serious conditions, exercise may exacerbate her health issues rather than provide therapeutic benefits.
B: high-protein diet Enhances nutritional status, supporting growth and recovery, which is crucial for managing her recurrent infections and overall health.
C: cardiac transplantation Provides a potential solution to her severe cardiac issues, addressing the underlying cause of her symptoms and significantly improving her quality of life.
D: nocturnal ventilatory support Assists in managing respiratory difficulties, ensuring adequate ventilation during sleep, which is essential for her respiratory health given her recurrent chest infections.
Holoprosencephaly is associated with all of the following EXCEPT
Rationale:
Holoprosencephaly is associated with congenital brain malformations such as cyclopia, pituitary hypoplasia, and cebocephaly, but it is not linked to congenital toxoplasmosis, which involves different developmental issues.
A: cyclopia This condition is a classic manifestation of holoprosencephaly, where the forebrain fails to properly divide, leading to the formation of a single eye in the middle of the face.
B: pituitary hypoplasia This condition occurs alongside holoprosencephaly due to disruptions in the normal development of the pituitary gland, impacting hormonal functions and growth patterns in affected individuals.
C: cebocephaly Cebocephaly is characterized by a nose resembling a snout and is a direct result of holoprosencephaly, reflecting the incomplete separation of the cerebral hemispheres during early brain development.
Mucopolysaccharidoses (MPS) affect many solid organs, the brain is spared in
Rationale:
MPS VI (Maroteaux-Lamy) affects many solid organs but spares the brain.
MPS VI is characterized by a deficiency in arylsulfatase B, leading to skeletal and visceral manifestations while preserving neurological function. This unique feature differentiates it from other MPS types that significantly impact cognitive abilities and brain structure.
A: MPS I (Hurler) Involves severe neurological impairment due to the accumulation of glycosaminoglycans, directly affecting brain function and development.
B: MPS II (Hunter) Also leads to cognitive decline and behavioral issues, impacting the central nervous system, which is a hallmark of this disorder.
C: MPS III (Sanfilippo) Primarily affects the brain, resulting in profound neurological deterioration and behavioral problems, distinguishing it from MPS VI.
You suspect a metabolic problem in a 30-day-old girl presented with poor feeding, vomiting, lethargy, and convulsion. Previous sibling died with the same condition. Serum ammonia, pH, HCO3, and anion gap are normal. Of the following, the MOST likely diagnosis is
Rationale:
Aminoacidopathy. The clinical presentation and family history suggest a genetic metabolic disorder, and the normal serum ammonia levels point towards a disorder related to amino acid metabolism rather than others.
A: Porphyria typically presents with photosensitivity and abdominal pain, which are not observed in this case, making it an unlikely diagnosis for the symptoms described.
B: Galactosemia usually leads to jaundice, hepatomegaly, and cataracts, which are absent in this infant, indicating that it does not align with the observed clinical signs.
C: Organic acidemia often presents with metabolic acidosis and elevated ammonia levels; however, the normal results in this case do not support this diagnosis as a probable cause.
During a routine physical examination, a solitary thyroid nodule is palpated in asymptomatic 10-year-old child. Of the following, the MOST likely cause is
Rationale:
Thyroid adenoma is the most likely cause of a solitary thyroid nodule in an asymptomatic 10-year-old child. This benign tumor commonly presents in pediatric patients and often remains asymptomatic, making it a frequent diagnosis in such cases.
A: Thyroid carcinoma presents with additional symptoms and is less common in children, especially without any signs of malignancy or systemic effects.
C: Thyroid abscess typically involves infection, which would likely present with symptoms such as pain, fever, or swelling, making it an unlikely cause in this asymptomatic child.
D: Thyroid cysts can occur but are generally fluid-filled and are less frequently associated with solitary nodules in children, particularly in the absence of other signs.
A 16-year-old boy has delayed puberty; he doesn’t develop secondary sexual characteristics; he has a normal stature according to his chronological age. Examination reveals an upper-to-lower segment ratio of 0.8 (normal ratio is more than 0.9). Of the following, the MOST important test to confirm diagnosis is
Rationale:
Plasma gonadotropins provide crucial information regarding the functioning of the testes and pituitary gland, which are essential in diagnosing conditions related to delayed puberty in this 16-year-old boy.
B: Growth hormone stimulation test assesses growth hormone levels and is useful for diagnosing growth disorders, but does not directly evaluate sexual maturation processes.
C: Serum prolactin levels primarily indicate pituitary functionality and are not specific for diagnosing delayed puberty or evaluating secondary sexual characteristics in this scenario.
D: Brain MRI is typically utilized to investigate structural abnormalities in the brain but does not directly assess hormonal levels necessary for diagnosing delayed puberty.
Matching: Lipidosis - GM1-gangliosidosis
Rationale:
Lipidosis is associated with GM1-gangliosidosis, which presents both cherry red spots in the retina and hepatosplenomegaly. This condition manifests through these distinct symptoms, indicating its broader impact on organ systems.
A: Cherry red spot. While GM1-gangliosidosis does present this symptom, it does not encompass the complete clinical picture of the condition on its own.
B: Hepatosplenomegaly. This symptom, although characteristic of GM1-gangliosidosis, fails to represent the entirety of the disease manifestations, which include other key symptoms.
D: Neither A nor B. This option overlooks the established clinical features of GM1-gangliosidosis, which are indeed marked by both cherry red spots and hepatosplenomegaly.
Type I diabetes mellitus is most often associated with
Rationale:
Type I diabetes mellitus is most often associated with antibodies to glutamic acid dehydrogenase. This autoimmune response targets pancreatic beta cells, leading to insulin deficiency, thus establishing a strong link between these antibodies and the onset of Type I diabetes.
A: mumps infection Mumps may cause various complications but lacks a direct correlation with the autoimmune destruction of pancreatic cells characteristic of Type I diabetes mellitus.
B: coxsackievirus Coxsackievirus has been implicated in beta-cell damage; however, it does not exhibit the same specific association with antibodies to glutamic acid dehydrogenase as Type I diabetes.
D: cow's milk While cow's milk proteins have been studied for potential links to diabetes, the evidence does not support a prominent association with antibody production or the autoimmune aspect of Type I diabetes.
All the following are clinical features of acute intermittent porphyria EXCEPT
Rationale:
Acute intermittent porphyria does not feature cutaneous photosensitivity. This condition primarily manifests with neurovisceral symptoms such as abdominal pain, neuropathy, and tachycardia, rather than skin-related issues.
A: neuropathy Neuropathy is a recognized symptom in acute intermittent porphyria, often presenting as pain or sensory disturbances due to nervous system involvement during acute attacks.
B: tachycardia Tachycardia frequently occurs during acute intermittent porphyria episodes, as the body responds to pain and stress, leading to an increased heart rate as a physiological reaction.
C: abdominal pain Abdominal pain is a hallmark symptom of acute intermittent porphyria, typically resulting from the accumulation of porphyrins that irritate the gastrointestinal tract during acute attacks.
The parents of a 2-year-old boy with Tay-Sachs disease ask you about the availability of prenatal testing in their pregnancy. When counseling this couple about prenatal diagnosis, it would be most appropriate to include which one of the following statements:
Rationale:
Testing can be performed on chorionic villus cells obtained as early as 10 weeks of pregnancy. This option accurately reflects the timeline for prenatal testing, allowing for early diagnosis of Tay-Sachs disease, which is crucial for informed decision-making during pregnancy.
B: Results of prenatal diagnosis testing for Tay-Sachs disease are considered investigational. This statement misrepresents the established nature of prenatal testing for genetic conditions, which is widely accepted and utilized.
C: Testing is only possible if the parents' mutations in the hexosaminidase gene are known. While knowing parental mutations can aid testing, it is not a prerequisite for performing prenatal testing.
D: The risk that they could have a similarly affected child in their next pregnancy is no greater than that of any other couple. This statement overlooks the specific genetic risk inherent to Tay-Sachs disease, which is elevated for carrier couples.
High-dose glucocorticoids (the equivalent of >10 times physiologic cortisol secretion) can be administered without requiring a subsequent tapering for
Rationale:
High-dose glucocorticoids can be administered without requiring a subsequent tapering for 7 days. This duration allows for the body to manage the dosage without significant adrenal suppression or withdrawal symptoms.
A: 5 day A 5-day administration does not provide ample time for the body to adapt, increasing the risk of adrenal insufficiency upon discontinuation of glucocorticoids.
C: 10 day A 10-day duration exceeds the recommended limit, potentially leading to unnecessary complications related to glucocorticoid withdrawal and requiring a tapering schedule to safely discontinue.
D: 14 day A 14-day period significantly surpasses the threshold for safe administration without tapering, heightening the likelihood of adverse effects and necessitating gradual dosage reduction to avoid serious health risks.
The normal level of serum thyroid-stimulating hormone in first week of term infants is up to
Rationale:
Up to 27.0 mIU/L.
The context indicates that the typical upper limit of serum thyroid-stimulating hormone (TSH) in infants during their first week of life is indeed 27.0 mIU/L, reflecting adequate thyroid function at this early stage.
A: 4.4 mIU/L This value is significantly lower than the normal range for TSH levels in term infants, indicating underactivity of the thyroid gland.
B: 9.5 mIU/L This level falls short of the established upper limit, suggesting insufficient stimulation of the thyroid gland during the critical early days of life.
C: 13.6 mIU/L While this is higher than 9.5 mIU/L, it still does not reach the normal threshold expected for TSH levels in newborns at this age.
Parathyroid crisis is manifested by the following EXCEPT
Rationale:
Parathyroid crisis is manifested by progressive polyuria. This option does not align with the typical symptoms associated with parathyroid crisis, which prominently includes elevated serum calcium levels, azotemia, and stupor.
A: serum calcium levels >15 mg/dL Elevated calcium levels are a hallmark of parathyroid crisis, leading to various systemic effects that significantly impact bodily functions and overall health.
C: azotemia The presence of azotemia indicates kidney dysfunction, which can occur during parathyroid crisis due to increased calcium levels affecting renal filtration and function.
D: stupor Stupor represents a severe neurological manifestation of parathyroid crisis, resulting from hypercalcemia affecting the central nervous system and leading to altered mental status.
A 9-year-old boy admitted to the hospital because of fracture of left femur due to a minor trauma. Past history revealed recurrent attacks of epistaxis and intermittent generalized bone pain. On examination, there is massive splenomegaly. Of the following, the MOST appropriate practical treatment of this disease is
Rationale:
Enzyme replacement is the most appropriate practical treatment for this disease. Given the boy's symptoms, including splenomegaly and bone pain, enzyme replacement addresses the underlying enzyme deficiency effectively, alleviating symptoms.
A: Gene therapy does not provide immediate relief or management for the symptoms presented, focusing instead on long-term genetic modifications that may not be feasible or beneficial in urgent situations.
B: Liver transplantation involves significant surgical risks and is typically reserved for severe liver failure, which is not indicated in this case where enzyme replacement is more suitable.
D: Substrate reduction agents aim to reduce the accumulation of harmful substances but do not directly replace the missing enzyme, leaving the underlying condition inadequately managed in this patient.
Matching: Hemizygotic male has complete syndrome
Rationale:
D: Nettleship full type ocular albinism is characterized by hemizygosity in males, leading to a complete syndrome that includes visual impairment and other systemic features commonly associated with albinism.
A: Chédiak-Higashi syndrome involves immunodeficiency and neurological issues, not solely characterized by hemizygosity or a complete syndrome related to ocular albinism.
B: Hermansky-Pudlak syndrome primarily affects pigmentation and causes bleeding issues; it does not represent a complete syndrome in hemizygotic males in the same way.
C: Waardenburg syndrome primarily involves hearing loss and pigmentation changes without the specific hemizygous male implications associated with full ocular albinism syndromes.
Thyroid disorders consist of a variety of diseases that require different treatment according to the cause. Of the following, the thyroid disorder that does not require treatment is
Rationale:
D: congenital thyroxine-binding globulin deficiency. This disorder typically does not require treatment as the condition is often benign and does not lead to significant complications, allowing for a non-intervention approach.
A: congenital hypothyroidism. This condition necessitates immediate treatment to prevent developmental delays and other serious health issues, making intervention critical for affected individuals.
B: endemic cretinism. This disorder arises from severe iodine deficiency, requiring treatment to restore thyroid function and prevent irreversible cognitive and physical disabilities in affected populations.
C: Hashimoto thyroiditis. This autoimmune thyroid disorder often leads to hypothyroidism, requiring treatment to manage hormone levels and prevent complications related to insufficient thyroid hormone production.
Patients with autoimmune Addison disease must be closely observed for the development of other autoimmune disorders. Of the following, the MOST commonly associated disorder in children is
Rationale:
Type 1 diabetes mellitus is the most commonly associated disorder in children with autoimmune Addison disease. This association arises due to shared autoimmune mechanisms, leading to a higher risk of multiple endocrine disorders in pediatric patients.
A: alopecia The link between alopecia and Addison disease is less pronounced, making it a less common comorbid condition compared to other autoimmune disorders in children.
B: vitiligo While vitiligo can occur alongside autoimmune conditions, its prevalence in children with Addison disease does not rival that of type 1 diabetes mellitus.
C: chronic active hepatitis This disorder is not typically associated with Addison disease in children, as the primary connections are more commonly linked to endocrine disorders rather than hepatic conditions.
Nocturnal enuresis is best described as
Rationale:
Nocturnal enuresis is best described as involuntary loss of urine during sleep. This condition typically occurs in children and involves a lack of control over urination while the individual is asleep, distinguishing it from daytime urinary issues.
A: Voluntary loss of urine during sleep. This option inaccurately suggests that the individual consciously chooses to urinate, which contradicts the fundamental nature of nocturnal enuresis as an involuntary action.
C: Involuntary loss of urine during the day. This description misplaces the occurrence of enuresis, as it specifically pertains to nighttime episodes and not to daytime incidents of urination.
D: Voluntary loss of urine during the day. This choice implies a conscious decision to urinate, which diverges from the definition of enuresis, focusing instead on daytime behavior rather than nocturnal events.
A 14-month-old male of Northern European ancestry experienced an upper respiratory tract infection and anorexia. On the second day of the illness, he began to vomit, and by that evening he was unresponsive. On the way to the hospital, he had a generalized seizure lasting 10 minutes. At the hospital, he had a blood glucose of 10 mg/dL; his urinalysis showed no ketones. Liver function tests, anion gap, and serum ammonia were all normal. The most likely diagnosis is
Rationale:
Medium-chain acyl CoA dehydrogenase deficiency is the most likely diagnosis. The clinical presentation, including hypoglycemia and absence of ketones, aligns with this metabolic disorder, which disrupts fatty acid oxidation, particularly under stress.
B: maple syrup urine disease. This condition typically presents with distinctive urine characteristics and neurological symptoms due to branched-chain amino acid accumulation, which is not indicated here.
C: glutaric aciduria type I. This disorder usually involves movement disorders and is characterized by specific metabolic derangements not observed in this patient's symptomatology or test results.
D: glutamate formiminotransferase deficiency. This metabolic condition primarily affects folate metabolism and generally presents with developmental delays and seizures, lacking the acute presentation seen in this case.
In mucopolysaccharidosis, disproportionate severe CNS involvement with mild physical features is unique to
Rationale:
D: Sanfilippo disease exhibits disproportionate severe central nervous system involvement while physical features remain relatively mild, distinguishing it from other mucopolysaccharidoses where physical manifestations are more pronounced alongside neurological symptoms.
A: Scheie disease typically presents with milder symptoms both physically and neurologically, lacking the severe CNS involvement seen in Sanfilippo disease, thus failing to meet the criteria.
B: Hurler disease is characterized by significant physical features alongside neurological decline, which does not align with the unique presentation of mild physical traits in Sanfilippo disease.
C: Hunter disease shows marked physical abnormalities and varying CNS involvement, contrasting with the distinctive mild physical features coupled with severe CNS issues found in Sanfilippo disease.
A 2-year-old boy presented with growth retardation, hepatomegaly, and recurrent attacks of hypoglycemia; biochemical study reveals elevated blood lactate, triglyceride, and uric acid levels. All the following are complications of this disease EXCEPT
Rationale:
C: Cardiomyopathy is not a complication of this disease, as the primary issues revolve around metabolic disturbances, specifically affecting the liver and energy regulation, rather than cardiac function or structure.
A: Pancreatitis can occur due to metabolic dysregulation and is associated with high triglyceride levels, leading to inflammation of the pancreas in such metabolic disorders.
B: Renal failure may arise from the accumulation of toxic metabolites in the kidneys, exacerbated by the underlying metabolic disorder affecting multiple organ systems and their functions.
D: Hepatic adenoma can develop as a consequence of chronic liver disease and metabolic dysregulation, particularly in conditions with prolonged liver stress like this patient's metabolic disorder.