investigations
Last reviewed 01/2018
Investigations:
- plasma methionine and homocystine levels are elevated
- homocystine is excreted in the urine
- plasma cystine levels are reduced
- positive urine cyanide-nitroprusside test
Urine or serum samples should be rapidly deproteinised prevent the formation of disulphide bonds between proteins and homocyst(e)ine.
Ref: Stantbury JB et al (1983). The Metabolic Basis of Inherited Disease, 5th edn. McGraw-Hill.