ABO blood group system the precise glycosyl transferase set that confers the A, B and O epitopes. Blood groups are inherited from both parents. The ABO blood type is controlled by a single gene (the ABO gene) with three types of alleles inferred from classical genetics: "i", "I", and "I". The "I" designation stands for isoagglutinogen, another term for antigen. The gene encodes a glycosyltransferase—that is, an enzyme that modifies the carbohydrate content of the red blood cell antigens. The gene is located on the long arm of the ninth chromosome (9q34). The "I" allele gives type A, "I" gives type B, and "i"
Blood type diet Blood type diet The blood type diets are fad diets advocated by several authors, the most prominent of whom is Peter J. D'Adamo. These diets are based on the notion that blood type, according to the ABO blood group system, is the most important factor in determining a healthy diet, and each author recommends a distinct diet for each blood type. The consensus among dietitians, physicians, and scientists is that these diets are unsupported by scientific evidence. In what was apparently the first study testing whether there was any benefit to eating the "right" diet according to one's blood type,