What is Homocystinuria?

Homocystinuria is an inherited disorder. In this disorder, the body is unable to process some of the building blocks of the body. These building blocks, called amino acids, make up proteins. Proteins perform many of the body’s functions and make up its structure. In homocystinuria, an enzyme called cystathionine beta-synthase (CBS) is needed to break down amino acids called methionine and homocysteine. When CBS is missing, these amino acids are not broken down correctly and build up in the body. High homocysteine levels can lead to health problems. Multiple forms of homocystinuria exist. They have different signs, symptoms and genetic causes. Symptoms include problems with the eyes, skeletal system, blood, and brain. Symptoms can vary and not all affected people have all of the findings. The severity of the symptoms can also vary. Some people with a mild form may not show symptoms until childhood or adulthood. People with severe forms can show symptoms as babies.

Symptoms of Homocystinuria can include:

  • Myopia (nearsightedness)
  • Ectopia lentis (lens of the eye moves to the wrong place)
  • Tall and slender body shape
  • Osteoporosis (fragile bones)
  • Curved spine
  • Chest abnormalities (Chest caved in or pointed out)
  • Blood clotting problems
  • Developmental delay (learning problems)
  • Behavior problems
  • Seizures
  • Dystonia (movement problems)

Homocystinuria is typically diagnosed by a metabolic geneticist. To find genetic services near you, ask your doctor or visit the Clinical Services Search Engine available on the American College of Medical Genetics webpage.

We use cookies to ensure that we give you the best experience on our website. By continuing to browse this site, you are agreeing to our use of cookies.

Continue Find out more about our use of cookies and similar technology

This content comes from a hidden element on this page.

The inline option preserves bound JavaScript events and changes, and it puts the content back where it came from when it is closed.

Remember Me