Lysosomal Storage Diseases

Question 1

Fabry’s disease

Answer 1

Findings: Peripheral neuropathy of hands/feet, angiokeratomas, cardiovascular/renal disease
Deficient Enzyme: alpha-galactosidase A
Accumulated Substrate: Ceramide trihexoside
Inheritance: XR

Question 2

Gaucher’s disease

Answer 2

Findings: Most common.
Hepatosplenomegaly, aseptic necrosis of femur, bone crises, Gaucher's cells A (macrophages that look like crumpled tissue paper)
Deficient Enzyme: Glucocerebrosidase
Accumulated Substrate: Glucocerebroside
Inheritance: AR

Question 3

Niemann-Pick disease

Answer 3

Findings: Progressive neurodegeneration, hepatosplenomegaly, cherry-red spot on macula, foam cells B
Deficient Enzyme: Sphingomyelinase
Accumulated Substrate: Sphingomyelin
Inheritance: AR

Question 4

Tay-Sachs disease

Answer 4

Findings: Progressive neurodegeneration, developmental delay, cherry-red spot on macula, lysosomes with onion skin, no hepatosplenomegaly (vs. Niemann-Pick)
Deficient Enzyme: Hexosaminidase A
Accumulated Substrate: GM2ganglioside
Inheritance: AR

Question 5

Krabbe’s disease

Answer 5

Findings: Peripheral neuropathy, developmental delay, optic atrophy, globoid cells
Deficient Enzyme: Galactocerebrosidase
Accumulated Substrate: Galactocerebroside
Inheritance: AR

Question 6

Metachromatic leukodystrophy

Answer 6

Findings: Central and peripheral demyelination with ataxia, dementia
Deficient Enzyme: Arylsulfatase A
Accumulated Substrate: Cerebroside sulfate
Inheritance: AR

Question 7

Hurler’s syndrome

Answer 7

Findings: Developmental delay, gargoylism, airway obstruction, corneal clouding, hepatosplenomegaly
Deficient Enzyme: alpha-L-iduronidase
Accumulated Substrate: Heparan sulfate, dermatan sulfate
Inheritance: AR

Question 8

Hunter’s syndrome

Answer 8

Findings: Mild Hurler’s + aggressive behavior, no corneal clouding
Deficient Enzyme: Iduronate sulfatase
Accumulated Substrate: Heparan sulfate, dermatan sulfate
Inheritance: XR