Homocystinuria is a rare inherited disease that causes a deficiency of one of several enzymes needed for the breakdown of food (metabolism). This enzyme deficiency may cause a buildup of homocysteine in the blood. Excess homocysteine may be released in the urine.
Babies born with homocystinuria may fail to grow and gain weight (failure to thrive) and may experience developmental delays. People with homocystinuria may develop diseases of the heart and blood vessels at a young age. If homocystinuria is not diagnosed in infancy, other problems may develop, including:
Partial dislocation of the lens of the eyes (ectopia lentis).
People with homocystinuria may have a thin appearance, with long, slender arms, legs, fingers, and toes. These features have been described as "marfanoid" because of the similarity to Marfan's syndrome.
Treatment for homocystinuria may include eating foods low in certain amino acids and taking vitamin supplements and medicine to enhance the breakdown of homocysteine.
Rezvani I, Rosenblatt DS (2011). Methionine section of Defects in metabolism of amino acids. In RM Kliegman et al., eds., Nelson Textbook of Pediatrics, 19th ed., pp. 425â€“429. Philadelphia: Saunders.
ByHealthwise StaffPrimary Medical ReviewerE. Gregory Thompson, MD - Internal MedicineAdam Husney, MD - Family MedicineMartin J. Gabica, MD - Family Medicine