Homocystinuria Flashcards
1
Q
What is it?
A
a rare autosomal recessive disease caused by a deficiency of cystathionine beta synthase. This results in severe elevations in plasma and urine homocysteine concentrations.
2
Q
features
A
- often patients have fine, fair hair
- musculoskeletal
- neurological:
- ocular
downwards (inferonasal) dislocation of lens
severe myopia - increased risk of arterial and venous thromboembolism
- malar flush, livedo reticularis
3
Q
what musculoskeletal features are there
A
Marfanoid body habitus: arachnodactyly etc
osteoporosis
kyphosis
4
Q
what neurological features are there?
A
may have learning difficulties, seizures
5
Q
what ocular features
A
downwards (inferonasal) dislocation of lens
severe myopia
6
Q
Ix
A
increased homocysteine levels in serum and urine
cyanide-nitroprusside test: also positive in cystinuria
7
Q
Mx
A
vitamin B6 (pyridoxine) supplements.
