Genetics/Heredity.

Synopsis Homocystinuria is an inherited disorder of the metabolism of the amino acid methionine. Homocystinuria is thought to be inherited as an autosomal recessive genetic trait, which means the gene defect is unknowingly passed down from generation to generation. This faulty gene only emerges when two carriers have children together and pass it to their offspring. For each pregnancy of two such carriers, there is a 25% chance that the child will be born with the …

…because the disease itself gets transmitted sexually; autosomal recessive. Another area is biochemistry. It is the recessive condition in which the enzyme cystathione synthetase converts homocysteine and serine into cystathione, a precursor of cysteine, is missing. Deficiency of this enzyme has widespread consquences in connective tissure, circulation, and nervous system. Bibliography Human Diseases and Conditions. Ed. Neil Izenberg, Vol. 1, Carles Scribner's Sons, NY. 2000. Internet; http://cancerweb.ncl.ac.uk/ Internet; http://www.nlm.nih.gov/