描述
Cystathionine Beta-Synthase Deficiency (CBS Deficiency; Homocystinuria) is an autosomal recessive disease caused by a mutation in the CBS gene which codes for cystathionine beta-synthase. A deficiency in this enzyme results in accumulation of L-cystathionine, homocysteine, and L-homocystine in plasma and urine; and L-methionine and ornithine in plasma. Symptoms include osteoporosis, myopia, fatty-liver, mental retardation, and early death. Treatment includes folic acid, vitamin B6, vitamin B12, and a methionine-restricted diet.