Homocystinuria is an autosomal recessive metabolic disorder which results in the accumulation of homocysteine due to decreased activity of cystathionine beta-synthase.
Features of homocystinuria include:
- Myopia Ectopia lentis (=lens dislocation)
- Low IQ
- Marfanoid body habitus
- Thromboembotic events
Homocystinuria is also associated with malar flush and livedo reticularis.
- Elevated plasma homocystine and methionine
- Elevated urinary homocystine
- Methionine/protein-restricted diet
- Pyridoxine (vitamin B6; a cofactor for cystathionine beta-synthase )
- Two types of homocystinuria exist – one responds well to pyridoxine, the other doesn’t
- Possibly B12/folate supplements – these encourage conversion of homocystine back to methionine.
Harvey Mudd, S. et al. The natural history of homocystinuria due to cystathionine beta synthase deficiency. Am J Hum Genet. 1985; 37(1): 1-31.
OMIM: Homocystinuria. Avaliable at http://omim.org/entry/236200?search=homocystinuria&highlight=homocystinuria