Dryja et al. (1996) summarized early reports of the most famous family with dominantly inherited night blindness, that descendant for some 11 generations from Jean Nougaret (1637-1719), a butcher from Provence who settled in Vendemian, a small village ... Dryja et al. (1996) summarized early reports of the most famous family with dominantly inherited night blindness, that descendant for some 11 generations from Jean Nougaret (1637-1719), a butcher from Provence who settled in Vendemian, a small village near Montpellier in the south of France. Florent Cunier, the Belgian ophthalmologist who founded Annales d'oculistique, heard of the family, examined some affected members, and stimulated M. Chauvet, a local antiquarian, to assemble the family genealogy. It was Chauvet who showed that Nougaret was the common ancestor of all persons in the district with night blindness. His genealogy listed 629 persons of whom 86 were night blind. Cunier (1838) published the findings. Nettleship (1907) followed up on the family. (An interesting biography of Nettleship was published in JAMA (Anonymous, 1970)). By that time, 135 night-blind persons were known. Vision was unimpaired in daylight, the fundi were normal, and general health was excellent. The excess of normal over affected observed in this family among offspring of affected persons may be a matter of incomplete penetrance or incomplete recording of mild cases--a view subscribed to by the geneticist William Bateson who discussed the paper. Attempts at further follow-up by Dejean and Gassenc (1949) indicated that the village inhabited by Nougaret's descendants was no longer an isolate.
Dryja et al. (1996) reported that affected descendants of Jean Nougaret who suffer from congenital night blindness carry a missense mutation in the gene encoding the alpha subunit of rod transducin (GNAT1), the G protein that couples rhodopsin ... Dryja et al. (1996) reported that affected descendants of Jean Nougaret who suffer from congenital night blindness carry a missense mutation in the gene encoding the alpha subunit of rod transducin (GNAT1), the G protein that couples rhodopsin to cGMP-phosphodiesterase in the phototransduction cascade. They analyzed 2 affected sibs for 11 genes in the phototransduction cascade and in both they detected an abnormality in exon 2 of the alpha subunit of rod transducin by SSCP analysis. Sequencing revealed a point mutation in codon 38 (139330.0001) resulting in a G38D amino acid change. No other changes in the coding region or flanking intron sequences were found by SSCP. Dryja et al. (1996) reported that subsequent analysis of 27 relatives revealed that the mutation was present only in affected family members. Dryja et al. (1996) noted that gly38 is a highly conserved residue among heteromeric G proteins including p21(RAS) (see 190020).