• Home

Home > Medical Reference > Encyclopedia (English)

Toggle: English / Spanish

Homocystinuria

• Overview
• Symptoms
• Treatment
• Prevention

Alternative Names:

Cystathionine beta synthase deficiency

Symptoms:

• A family history of homocystinuria
• Nearsightedness
• Flush across the cheeks
• Tall, thin build
• Long limbs
• High-arched feet (pes cavus)
• Knock-knees (genu valgum)
• Pectus excavatum
• Pectus carinatum
• Mental retardation
• Psychiatric disease

Signs and tests:

During a physical examination of the child, the health care provider may notice a tall, thin (Marfanoid) stature with deformity of the chest or scoliosis. If there is poor or double vision, an ophthalmologist should perform a dilated eye exam where dislocation of the lens of the eye or nearsightedness may be observed.

There may be a history of frequent blood clots. Mental retardation, slightly low IQ, or psychiatric disease are common.

Tests:

• An amino acid screen of blood and urine shows elevated methionine and homocysteine levels.
• A skeletal x-ray shows osteoporosis.
• A standard ophthalmic exam confirms nearsightedness and a dislocated lens. Affected children may also have cataracts , glaucoma , and retinal detachment .
• A liver biopsy and enzyme assay shows an abnormality of the enzyme cystathionine beta synthase.
• A skin biopsy with a fibroblast culture shows an abnormality of cystathionine beta synthase.

Genetic testing may show a mutation in the cystathionine beta synthase gene.

• Review Date: 8/11/2006
• Reviewed By: Brian Kirmse, MD, Mount Sinai School of Medicine, Department of Human Genetics, New York, NY. Review provided by VeriMed Healthcare Network.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial process . A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 1997-2007 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.