Homocystinuria

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Pectus excavatum

Cystathionine beta synthase deficiency

There is no specific cure for homocystinuria. However, many people respond to high doses of vitamin B-6 (also known as pyridoxine). Slightly less than half of patients respond to this treatment; those that do respond need supplemental vitamin B-6 for the rest of their lives. Those who do not respond require a low methionine diet, and most will need treatment with trimethylglycine (a medication also known as betaine).

Neither a low-methionine diet nor medication will improve existing mental retardation. Medication and diet should be closely supervised by a physician with experience treating homocystinuria.

A normal dose folic acid supplement and occasionally added cysteine (an amino acid) in the diet is helpful.

Although no specific cure exists for homocystinuria, approximately half of the affected people can be helped by vitamin B-6 therapy.

If the diagnosis is made while a patient is young, a low methionine diet started promptly and strictly adhered to can prevent some mental retardation and other complications of the disease. For this reason, some states screen for homocystinuria in all newborns.

Unfortunately, patients with persistent increases in blood homocysteine levels are at increased risk for blood clots, which can cause significant medical problems and shorten life span.

Most serious complications result from blood clots, and these episodes can be life threatening. Dislocated lenses of the eyes can severely impair vision and lens replacement surgery should be considered. Mental retardation is a serious consequence of the disease which can be moderated if diagnosed early.

Call your health care provider if you or a family member show signs and symptoms suggestive of this disorder, particularly if there is a family history of homocystinuria. Also call if you have a family history and are planning to have children.

Review Date: 08/11/2006
Reviewed By: Brian Kirmse, MD, Mount Sinai School of Medicine, Department of Human Genetics, New York, NY. Review provided by VeriMed Healthcare Network.