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Zorluk: ZorPediatric Genetic and Metabolic Disorders

Correctly map each pediatric patient's specific clinical vignette to the corresponding underlying biochemical or genetic defect.

  • A 7-month-old infant of Eastern European Jewish descent presents with progressive loss of motor skills, massive hepatosplenomegaly, and a prominent macular cherry-red spot.Deficient activity of acid sphingomyelinase
  • A 6-month-old infant presents with severe developmental regression, extreme irritability, early hypotonia progressing to spasticity, absent deep tendon reflexes, and optic atrophy.Deficient activity of galactocerebrosidase
  • A 20-month-old toddler presents with a recent onset of frequent falls, ataxia, and progressive loss of expressive language. Examination reveals peripheral neuropathy with absent reflexes.Deficient activity of arylsulfatase A
  • A 7-year-old boy presents with declining school performance, aggressive behavioral changes, and new-onset spastic quadriparesis. Laboratory testing reveals primary adrenal insufficiency.Defective peroxisomal transmembrane transport of very long-chain fatty acids

Cevap

The infant with organomegaly and a cherry-red spot maps to sphingomyelinase deficiency (Niemann-Pick type A). The infant with early regression and optic atrophy maps to galactocerebrosidase deficiency (Krabbe disease). The toddler with ataxia maps to arylsulfatase A deficiency (Metachromatic leukodystrophy). The school-aged boy with adrenal insufficiency maps to defective peroxisomal transport of very long-chain fatty acids (X-linked adrenoleukodystrophy).
Each presentation highlights key differentiating features of pediatric neurometabolic disorders, allowing accurate mapping to their specific underlying enzymatic or transport defects based on age of onset, specific neurologic signs (e.g., optic atrophy vs ataxia), and systemic involvement (e.g., organomegaly, adrenal insufficiency).

Adım Adım Çözüm

1
Analyze the first vignette describing an infant with hepatosplenomegaly and a cherry-red macula.
Identified as Niemann-Pick disease type A.
The combination of neurodegeneration, organomegaly, and a cherry-red macula is pathognomonic for sphingomyelinase deficiency. (Note: Tay-Sachs also features a cherry-red spot but lacks organomegaly).
2
Analyze the second vignette describing early infancy regression, absent reflexes, and optic atrophy.
Identified as Krabbe disease.
The early onset of regression combined with peripheral neuropathy (areflexia) and optic atrophy points directly to galactocerebrosidase deficiency.
3
Analyze the third vignette describing a toddler with ataxia and peripheral neuropathy.
Identified as Metachromatic leukodystrophy.
Toddler-onset (late-infantile) ataxia, motor regression, and peripheral neuropathy correlate specifically with arylsulfatase A deficiency.
4
Analyze the fourth vignette describing a school-aged boy with neurodegeneration and primary adrenal insufficiency.
Identified as X-linked adrenoleukodystrophy.
The unique combination of childhood-onset cerebral demyelination and adrenal dysfunction is driven by a genetic defect in the ABCD1 transporter, impairing peroxisomal transport of very long-chain fatty acids.

Anahtar Kavram

Clinical differentiation of pediatric lysosomal storage diseases and peroxisomal disorders based on characteristic neurologic and systemic findings.
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Pediatric Genetic and Metabolic Disorders

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