Medical Q&As

Homocysteine - explain?

My friend\'s 18-year-old blind son has just been diagnosed as having a syndrome called \"homocysteine\". Do you have any further information on this apparently rare condition? I\'ve searched the web to no avail.

Homocysteine is an amino acid and if excessive levels of this substance accumulate in the body the condition is referred to as hyperhomocysteinaemia. Excessive levels of homocysteine can result in irritation of the blood vessels, which can lead on to atherosclerosis or hardening of the arteries. Many people with high homocysteine levels in their blood do not get enough folic acid, vitamin B6 or vitamin B12 in their diet. Increasing the levels of these vitamins in the diet can reduce the previously high levels of homocysteine in the blood. Hyperhomocysteinaemia can also happen as a result of a congenital deficiency of the specific enzymes that are responsible for processing homocysteine in the body. It has also been reported in association with kidney disease and under activity of the thyroid gland. An association has also been established between hyperhomocysteinaemia and damage to the retina in those suffering from diabetes. Perhaps your friendís blind son has a congenital deficiency of the enzymes that process homocysteine but it would be unwise of me to speculate beyond that tentative suggestion because I am not in possession of all the relevant facts.