Homocysteine Analysis

Elevations in plasma homocysteine levels may be associated with homocystinuria, cobalamin disorders, and vitamin B12 or folic acid deficiencies. Measurement of plasma homocysteine can be used to monitor patients undergoing treatment for Certain cobalamin disorders (CblC, CblD and CblE), which are characterized by hypotonia, failure to thrive, developmental delay and megaloblastic anemia and result in elevated homocysteine levels.

Turnaround Time

10 days

CPT Code(s)

83090

Cost

$100

• Homocystinuria

Homocysteine is a non-protein amino acid that is synthesized through the conversion of methionine. Elevations in plasma homocysteine levels may be associated with homocystinuria, cobalamin disorders (cblC, cblD, and cblE), and vitamin B12 or folic acid deficiencies.

The symptoms of homocystinuria include lens dislocation, osteoporosis, skeletal abnormalities such as genu valgum or a pectus deformity, thrombotic events, intellectual disability and psychiatric/behavioral disturbances. However, the phenotype is variable. Certain cobalamin disorders (CblC, CblD and CblE), which are characterized by hypotonia, failure to thrive, developmental delay and megaloblastic anemia, also result in elevated homocysteine levels. Measurement of plasma homocysteine can be used to monitor patients undergoing treatment for these conditions.

Liquid chromatography-tandem mass spectrometry

Plasma: at least 0.5 ml of plasma is required to perform this analysis. Peripheral blood should be collected in a sodium heparin tube. Plasma should be spun down, separated, and frozen within 4 hours of collection to prevent false elevations in homocysteine levels.

Plasma should be sent frozen, preferably on dry ice, via overnight delivery.