Hozygous Cases for Hemoglobin J Mexico (α⁵⁰ (E3)Gln→Glu) Evidence for a Duplicated α Gene with Unequal Expression

Abstract

Hemoglobin J Mexico has been found in five generations of a large Algerian family. Nine subjects have 55% Hb J although their parents, siblings and offspring may have 31%, the usual quantity found in heterozygotes. Those with 55t Hb J are considered to be homozygous for a chromosome carrying both a normal a chain locus and a locus for α^J. The proportion of the abnormal hemoglobin in all the subjects is in favor of an unequal expression of both loci, the amount of protein synthesis dissected by the α^J gene being greater than that directed by the α^A. In two heterozygotes a slightly higher proportion af the Hb J (38%) suggests the presence of a angle normal a chain locus in trans. An associated α-thalassemia was excluded by biosynthetic studies in this family.