What Is Homocystinuria?

What Is Homocystinuria?

Homocystinuria is a rare inherited metabolic disorder that affects the body's ability to process the amino acid methionine. Methionine is an essential amino acid that is found in many foods, including meat, fish, poultry, eggs, dairy products, and beans.

In people with homocystinuria, a defect in the enzyme cystathionine beta-synthase (CBS) prevents the body from converting methionine into cystathionine. This leads to a build-up of methionine and homocysteine in the blood and urine.

High levels of homocysteine can damage the blood vessels and increase the risk of blood clots, heart disease, stroke, and other serious health problems.

What Are the Symptoms of Homocystinuria?

The symptoms of homocystinuria can vary depending on the severity of the disorder. Some people may have only mild symptoms, while others may have more severe symptoms that can lead to serious health problems.

Common symptoms of homocystinuria include:

- Brittle hair

- Thin hair

- Ectopia lentis (dislocation of the lens of the eye)

- Marfanoid habitus (tall, thin body type with long arms and legs)

- Intellectual disability

- Developmental delays

- Seizures

- Vision problems

- Hearing loss

- Bone problems

- Osteoporosis

- Kidney problems

How Is Homocystinuria Treated?

There is no cure for homocystinuria, but the disorder can be managed with treatment. Treatment typically involves a combination of dietary restrictions, vitamin supplements, and medications.

Dietary restrictions: People with homocystinuria need to limit their intake of foods that are high in methionine. These foods include meat, fish, poultry, eggs, dairy products, and beans.

Vitamin supplements: People with homocystinuria need to take vitamin B6 and folate supplements. These vitamins are necessary for the body to process methionine.

Medications: People with homocystinuria may also need to take medications to help reduce the risk of blood clots and other serious health problems. These medications may include aspirin, warfarin, and clopidogrel.

How Is Homocystinuria Diagnosed?

Homocystinuria is diagnosed with a blood test that measures the levels of homocysteine in the blood. A urine test can also be used to diagnose the disorder.

What Is the Prognosis for People with Homocystinuria?

The prognosis for people with homocystinuria depends on the severity of the disorder and the effectiveness of treatment. People who are diagnosed early and receive treatment can often live full and productive lives.

How Can Homocystinuria Be Prevented?

Homocystinuria is a genetic disorder, so it cannot be prevented. However, genetic counseling can help people who have a family history of the disorder to understand their risk of having a child with homocystinuria.