Biochem Flashcards
what enzyme is def in Fabry dz?
alpha-galactosidase A
what enzyme is def in Krabbe?
galactocerebrosidase
what are the clinical symptoms of Krabbe?
globoid cells, optic atrophy, developmental delay, peripheral neuropathy
what substrates are accumulated in Krabbe?
galactocerebroside, psychosine
what substrates are accumulated in Fabry?
ceramide, trihexoside
what enzyme is def in metachromatic leukodystrophy?
arylsulfatase A
what are the clinical symptoms of metachromatic leukodystrophy?
central and peripheral demyelination with ataxia, dementia
what substrates are accumulated in metachromatic leukodystrophy?
cerebroside sulfate
what are the second trimester quad screen values in Down?
low alpha fetoprotein
low estriol
high beta hCG
high inhibin A
quad screen values in Edward?
all low (low or normal inhibin A)
what is the unique quad screening test for Patau?
low PAPP-A
what paths are associated with inc nuchal translucency?
Down and Patau
5% of the causes for Down are
4%: Robertsonian translocation (2n=46)
1%: mosaicism (no maternal association, post-fertilization mitotic error)
what path is associated with inc sensitivity to vit D (hypercalcemia) and elfin facies?
Williams (microdeletion of ch#7)
trinucleotide repeat for friedreich ataxia?
GAA
trinucleotide repeat for huntington?
CAG
trinucleotide repeat for myotonic dystrophy?
CTG
what is the gene involved in myotonic dystrophy?
CTG expansion in the DMPK gene which leads to abnormal expression of myotonin protein kinase
what causes Prader Willi?
Maternal imprinting and Paternal deletion
what causes AngelMan?
Maternal deletion and Paternal imprinting
25% of the cause for Prader Willi is due to
Maternal uniparental disomy (Two imprinted maternal genes are inherited, no paternal gene received)
5% of the cause for AngelMan is due to
Paternal uniparental disomy (Two imprinted paternal genes are inherited, no maternal gene received)
what vit overdose lead to symptoms of pseudotumor cerebri (inc ICP, hydrocephalus, headache)?
vit A
what are symptoms of chronic vit A toxicity?
alopecia, dry skin (scaliness), hepatic toxicity and enlargement, arthralgias, pseudotumor cerebri
what are symptoms of acute vit A toxicity?
nausea, vomiting, vertigo, blurred vision
what vit def lead to nyctalopia?
nyctalopia (night blindness), vit A def
what are symptoms of vit A def?
bitot spots on conjunctiva, frequent infection (immunesuppressed), corneal degeneration, xerosis cutis (scaly skin)
what vit def is associated with corneal vascularization and inflammation of lips?
vit B2 (riboflavin)
what vit is req for glycogen phosphorylase and decarboxylation rxn?
vit B6 (pyridoxine)
vit B6 (pyridoxine) can be used to treat what glycogen storage dz?
McArdle
what enzyme is def in Fabry?
alpha galactosidase A
what are the clinical symptoms of Fabry dz?
peripheral neuropathy of hands/feet, angiokeratomas, cardiovascular/renal dz
3 glucogenic aa?
methionine, valine, histidine
amino acids necessary for purine synthesis?
GAG (Glycine, Aspartate, Glutamine)