Morphological Demonstration of Two Red Cell Populations in Human Females Heterozygous for Glucose-6-phosphate Dehydrogenase Deficiency

Abstract

IN 1961 Lyon¹ postulated that in the female one of the two X-chromosomes is inactivated. Though the exact timing of this occurrence is not known, two populations of cells will result, one carrying the paternal and the other carrying the maternal X-chromosome. In the heterozygous state for X-chromosomal diseases mosaicism of normal and pathological cells would be expected. Though this hypothesis is not applicable to all recessive traits, there is some evidence of its validity in favism. Several investigations have shown by indirect methods that two populations of red cells may occur in females heterozygous for glucose-6-phosphate dehydrogenase deficiency^2–4. Nevertheless, it has not yet been possible to demonstrate visually different types of erythrocytes.