Five generations of a protan + deutan family: genealogy, color vision and genomic DNA

Three generations of progeny of a couple of whom the husband was protan and the wife deuteranopic (Franceschetti, 1949) have been examined in 1986 and 1987. This couple had four childern, of whom three sons are deutan and one daughter, a double carrier, is phenotypically normal. This girl, in her turn and in exemplary fashion, has three children: one daughter, being a simple carrier, is phenotypically normal, whereas one son is protan and one son is deutan. A study of the genomic DNA of three normal subjects reveals the presence of two genes responsible for green and one gene responsible for red; the genomic DNA of a protanomalous subject shows a minor modification of the gene for red, while that of two deuteranopes shows a converted gene.