What is Homocystinuria Caused by Cystathionine Beta-Synthase Deficiency?
Homocystinuria caused by cystathionine beta-synthase deficiency, or CBS deficiency, is an inherited metabolic disease in which affected people cannot process certain amino acids, the building blocks of proteins, due to the lack of a particular enzyme. The disease causes an array of symptoms including eye problems, skeletal abnormalities, an increased risk for dangerous blood clots, and in some people it causes developmental delay or mental disability. Not all people with the disease exhibit all of the symptoms described below, and the severity of the symptoms varies widely from person to person. In some cases, people will reach adulthood before developing any symptoms. There are two forms of the disease: a type that responds well to treatment with vitamin B6 and a type that does not. People with B6-responsive CBS deficiency sometimes, but not always, have a less severe course of the disease than those with the B6-non-responsive form. The majority of people with CBS deficiency are nears
