Genetically determined electrophoretic variants of human red cell NADH diaphorase.

Abstract

SUMMARYHuman red cell NADH diaphorase isozyme patterns have been examined in blood samples from 2783 unrelated individuals by starch gel electrophoresis. Most people exhibit a single banded isozyme pattern, designated phenotype Dia 1. Twenty‐nine people with variant isozyme patterns were encountered. Five different phenotypes (Dia 2‐1, 3‐1, 4‐1, 5‐1 and 6‐1) were identified, which from family studies appear to represent heterozygous combinations of one or other of a series of rare alleles (Dia2, Dia3, Dia4, Dia5 and Dia6) with a common allele (Dia1) at an autosomal locus.Studies on the children of a first cousin marriage led to the identification of a sixth variant phenotype, Dia 2, which is believed to represent the homozygous genotype Dia2Dia2.Individually all of the variants were rare, although collectively the frequency of NADH diaphorase variants was about one in a hundred in European, Indian and Negro population samples. More than half the total number of variants observed were phenotype Dia 2‐1 or Dia 4‐1.The rare Dia6 allele probably determines a low activity form of NADH diaphorase.There was no evidence of linkage between the NADH diaphorase locus and several blood group and other autosomal gene loci.