Sphingolipidoses (non-thorough review) Flashcards
What is sphingosine?
18 carbon fatty acid (palmitic acid) and serine
What is ceramide?
Sphinosine + 1 fatty acid, so essentially it is SERINE WITH 2 FATTY ACIDS. By adding choline or a sugar in cermaide, we are going to build all major shpingolipidoses.
What does adding a P-CHOL to ceramide yield?
Sphingomyelin. Sphingomyelin becomes ceramide with sphingomyelinase, which is defective in Niemann - Pick.
Prominent symptom of Niemann-Pick?
Neurodegeneration is prominent, because of abundance of shingomyelinase in myelin.
Pathognomonic?
Lipid - laden machrophages and sometimes hepatosplenomegaly distinguishes its from other sphingolipidoses, especially Tay-Sachs with which they share the finding of cherry red spot on macula.
What does adding a GLU to ceramide yield?
Glucocerebroside. Glucocerebroside is turned back to ceramide with glucocerebbrosidase, which is defective in Gaucher’s disase.
Unique characteristics?
Clucocerebrosie accumulates within the RES so: Papaer-like macrophages with nucleus pushed aside, BONE marrow dysfunction->pancytopenia AND avascular necroses of femur or BONE crises.
Addition of a sialic acid molecule to glucocerebroside yields what?
GM2 ganglioside. It is converted back to glucocerebroside with hexosaminidase A, and a defect leads to Tay-Sachs disease.
Any unique feature?
Cherry red macula spots (along with N-P, but T-S has no hepatosplenomegaly or lipid laden macrophages), and ONION-skin lysosomes.
If you add a galactose molecule to GM2 what do you get?
Globoside. Galactocerebrosidase deficiency is seen is Krabbe.
Characteristic finding of Krabbe?
Globoid cells.
Krabbe vs ML?
1 moiety and 1 nervous system added in ML. ML has cer-gal-SO4 and affects the CNS as well
Characteristic of Fabry?
ONLY XR, angiokeratomas early, renal failure late.
