Lysosomal storage diseases

Question 1

What is Tay-Sach’s disease

Answer 1

Deficient enzyme: Hexosaminidase A

Accumulated substrate: GM2 ganglioside

Features: neurodegeneration, dev delay, cherry red spot, onion skin lysosome, no hepatosplenomegaly

Question 2

What is Fabry disease

Answer 2

Deficient enzyme: alpha galactosidase A

Accumulated substrate: Ceramide trihexoside

Features: neuropathy (pain), angiokeratomas (red spots), decreased sweat. Late renal failure and CVD

Question 3

What is metachromatic leukodystrophy

Answer 3

Deficient enzyme: Arylsulfatas A

Accumulated substrate: Cerebroside sulfate

Features: ataxia, dementia

Question 4

What is Krabbe disease

Answer 4

Deficient enzyme: Galactocerebrosidase

Accumulated substrate: Galactocerebroside

Features: Neuropathy, dev delay, optic atrophy, globoid cells (puffy)

Question 5

What is Gaucher disease

Answer 5

Most common

Deficient enzyme: Glucocerebrosidase

Accumulated substrate: Glucocerebroside

Features: Hepatosplenomegaly, easy brusing (low platelets), avascular necrosis, Gaucher cells (lipid-laden macrohpages, like paper)

Question 6

What is Niemann-Pick disease

Answer 6

Deficient enzyme: Sphingomyelinase

Accumulated substrate: Sphingomyelin

Features: Hepatospenomegaly, cherry red spot, foam cells (macrophages)

Question 7

What is Hurler syndrome

Answer 7

Deficient enzyme: alpha iduronidase

Accumulated substrate: Heparan and dermatan sulfate

Features: Dev delay, coarse features, bone problems, hepatosplenomegaly, corneal clouding

Question 8

What is Hunters syndrome

Answer 8

Mild Hurlers

Deficient enzyme: Iduronidate - 2 - sulfatase

Accumulated substrate: heperan. sulfate and dermatan sulfate

Features: No corneal clouding, mild hurlers

Question 9

Genetics of disease

Answer 9

All are autosomal recessive except:

Hunters and Fabry: X linked