Hyperhomocysteinaemia

**Definition:** A disease caused by deficiencies of vitamin B6, folic acid, or vitamin B12. Genetic defects in 5-MTHF reductase can consequently lead to hyperhomocysteinaemia. This disease is characterised by abnormally high level of homocysteine in the blood. This disease may present with cardiovascular disease, thrombosis, schizophrenia and osteoporosis. Confirmation is by identification of deficiency in a blood sample.