Homocystinuria Flashcards
1
Q
Inheritance
A
Autosomal recessive
2
Q
Deficiency in what enzyme? What does this cause?
A
deficiency of cystathionine beta synthase
=>severe elevations in plasma and urine homocysteine concentrations.
3
Q
Features
A
fine, fair hair
Marfanoid body habitus: arachnodactyly etc
osteoporosis
kyphosis
learning difficulties/ seizures
downwards (inferonasal) dislocation of lens
severe myopia
increased risk of arterial and venous thromboembolism
malar flush, livedo reticularis
4
Q
Diagnostic tests
A
Serum and urine homocysteine levels=> raised
cyanide-nitroprusside test (also positive in cystinuria)
5
Q
Treatment of homocysteinuria
A
vitamin B6 (pyridoxine) supplements.
6
Q
A
