USMLE Lysosomal Storage Diseases

What is the deficient enzyme in Fabry's disease?

alpha-galactosidase A

What is the accumulated substrate and inheritance in Fabry's disease?

ceramide trihexoside and XR

What are the findings in fabry's disease?

peripheral neuropathy of hands/feet, angiokeratomas, cardiovascular /renal disease

What is the deficient enzyme in Gaucher's disease?

Glucocerebrosidase

What is the accumulated substrate and inheritance in Gaucher's disease?

glucocerebroside and AR

What are the findings in Gaucher's disease?

hepatosplenomegaly, aseptic necrosis of femur, bone crises, gaucher's cells(macrophages that look like crumpled tissue paper)

What is the deficient enzyme in niemann-pick disease?

sphingomyelinase

What is the accumulated substrate and inheritance in niemann-pick disease?

sphingomyelin and AR

What are the findings in niemann-pick disease?

Progressive neurodegeneration, hepatosplenomegaly, cherry-red spot on macula, foam cells

What is the deficient enzyme in Tay-Sachs disease?

Hexosaminidase A

What is the accumulated substrate and inheritance in Tay-Sachs disease?

GM2 ganglioside and AR

What are the findings in Tay-Sachs disease?

Progressive neurodegeneration, developmental delay, cherry red spot on macula, lysosomes with onion skin, NO HEPATOSPLENOMEGALY (vs niemann-pick)

What is the deficient enzyme in Krabbe's disease?

beta-galactocerebrosidase

What is the accumulated substrate and inheritance in Krabbe's Disease?

galactocerebroside and AR

What are the findings in Krabbe's Disease?

peripheral neuropathy, developmental delay, optic atrophy, globoid cells

What is the deficient enzyme in Metachromatic leukodystrophy?

Arylsulfatase A

What is the accumulated substrate and inheritance in Metachromatic leukodystrophy?

Cerebroside sulfate and AR

What are the findings in Metachromatic leukodystrophy?

central and peripheral demyelination with ataxia, dementia.

what is the deficient enzyme in hurler's syndrome?

alpha-L-iduronidase

What is the accumulated substrate and inheritance in hurler's syndrome?

heparan sulfate, dermatan sulfate, and AR

What are the findings in hurler's syndrome?

Developmental delay, gargoylism, airway obstruction. corneal clouding, hepatosplenomegaly

What is the deficient enzyme in hunter's syndrome?

iduronate sulfatase

What is the accumulated substrate and inheritance in hunter's syndrome?

heparan sulfate. dermatan sulfate and XR

What are the findings in hunter's syndrome?

mild hurler's + aggressive behavior, no corneal clouding.

Which group has increased incidence of tay-sachs, niemann-pick and some forms of gauchers disease?

ashkenazi jews