Storage diseases Flashcards
Von Gierke disease (type one)
Glycogen Storage Disease ; AR
Deficient Enzyme: Glucose-6-phosphatase
Findings: Hepatomegaly, Severe fasting hypoglycemia, ^^ glycogen in live, ^ blood lactate + triglycerides and uric acid
Pompe disease (type 2)
Glycogen Storage Disease ; AR
Deficient Enzyme: Lysosomal a-1,4 glucosidase (acid maltase)
Findings: Cardiomegaly, hypertrophic cardiomyopathy, exercise intolerance
Cori disease (type 3)
Glycogen Storage Disease ; AR
Deficient Enzyme: Debranching enzyme (a-1,6-glucosidase)
Findings: Milder form of type I (Von Gierke disease) with normal lactate levels
McArdle disease (type 5)
Glycogen Storage Disease ; AR
Deficient Enzyme: Skeletal muscle glycogen phosphorylase ( myophosphorylase)
Findings: ^ glycogen in muscle, but cannot break it down -> painful muscle cramps, myoglobinuria (red urine) with exercise and arrhythmia from electrolyte abnormalities
Fabry disease
Lysosomal storage disease- Sphingolipidoses -XR
Deficient Enzyme: a-galactosidase A
Accumulated Substrate: Ceramide trihexoside
Findings: Peripheral neuropathy of hands/feet, angiokeratomas, cardiovascular/renal disease
Gaucher disease
Lysosomal storage disease- Sphingolipidoses -AR
Deficient Enzyme: Glucocerebrosidase (B-glucosidase)
Accumulated Substrate: Glucocerebroside ( in phagocytes)
Findings: Most common, Hepatosplenomegaly, pancytopenia, aseptic nevrosis of femur/ bone crises, Gaucher cells ( lipid-laden macrophages resembling crumpled tissue paper)
Niemann-Pick Disease
Lysosomal storage disease- Sphingolipidoses -AR
Deficient Enzyme: Sphingomyelinase
Accumulated Substrate: Sphingomyelin ( in phagocytes)
Findings: Progressive neurodegeneration, hepatosplenomegaly, foam cells ( lipid-laden macrophages), “cherry red” spot on macula
Tay-Sachs disease
Lysosomal storage disease- Sphingolipidoses -AR
Deficient Enzyme: Hexosaminidase A
Accumulated Substrate: GM2 ganglioside
Findings: Progressive neurodegeneration, developmental delay, “cherry-red” spot on maculate, lysosome with onion skin, NO HEPATOSPLENOMEGALY
Krabbe disease
Lysosomal storage disease- Sphingolipidoses -AR
Deficient Enzyme: Galactocerebrosidase
Accumulated Substrate: Galactocerebroside, psychosine
Findings: Peripheral neuropathy, developmental delay, optic atrophy, globoid cells
Metachromatic leukodystrophy
Lysosomal storage disease- Sphingolipidoses -AR
Deficient Enzyme: Arylsulfatase A
Accumulated Substrate: Cerebroside sulfate
Findings: Central and peripheral demyelination with ataxia, dementia
Hurler syndrome
Lysosomal storage disease- Mucopolysaccharidoses-AR
Deficient Enzyme: a-l-iduronidase
Accumulated Substrate: Heparan sulfate, dermatan sulfate
Findings: Developmental delay, gargoylism, airway obstruction, corneal clouding, hepatosplenomegaly
Hunter syndrome
Lysosomal storage disease- Mucopolysaccharidoses-XR
Deficient Enzyme: Iduronate sulfatase
Accumulated Substrate: Heparan sulfate, dermatan sulfate
Findings: Mild Hurler + aggressive behavior, no corneal clouding
” Cherry-red” spots on macula
Tay-Sachs - NO hepatosplenomegaly
Niemann-Pick- hepatosplenomegaly
Hepatosplenomegaly
Hurler - a-L-iduronidase( hep/dermantan sulfate) - corneal clouding
Hunter - Iduronate sulfatase (hep/dermatan sulfate) - non corneal clouding
Nieman pick - sphingomyelinase (sphingomyelin) - Progressive neurodegeneration
Gaucher- Glucocerebrosidase (glucocerebroside) - bone crises
Hepatomegaly
Von Gierke (type 1) - Glucose-6-phosphatase Cori disease(type 3)- Debranching enzyme (a-1,6-glucosidase)
