Distance and Sequence of the Loci for Protan and Deutan Defects and for Glucose-6-Phosphate Dehydrogenase Deficiency

PROOF for the separate localization on the human X -chromosome of the protanopia-protanomaly alleles and of the deuteranopia-deuteranomaly alleles requires the demonstration of: (1) non-allelic compound hemizygous males which in conditions of equilibrium should occur once among a thousand men (one in eighty colour-blind men) or of (2) crossover males in families combining both classes of defect.