[Absence of the palmar c triradius. Dermatoglyphic and geneologic study of a genetic character transmitted since the 17th century in a Quebec family].
A dermatoglyphic research on the absence of the palmar c-triradius was carried out in a Canadian family line originating from a French married couple who settled in the Quebec City area in 1649. Of the 51 individuals examined, 34 showed that c-triradius was missing on one or both palms. The study of the family tree and of the data confirms the hypothesis that an absent palmar c-triradius is an autosomal dominant trait transmitted by an heterozygous genotype with, in the present observation, an incidence of 66,6% and an estimated penetrance of 44,1%.
D002869:Chromosome Aberrations; D025063:Chromosome Disorders; D003878:Dermatoglyphics; D005260:Female; D005385:Fingers / Q000002:abnormalities / Q000000981:diagnostic imaging; D005528:Foot / Q000000981:diagnostic imaging; D005602:France / Q000208:ethnology; D006225:Hand / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D010375:Pedigree; D010641:Phenotype; D011792:Quebec; D011859:Radiography; D012730:Sex Chromosomes; D012737:Sex Factors; D013997:Time Factors
L'absence du triradius C palmaire. Etude dermatoglyphique et généalogique d'un caractère génétique, transmis depuis le dix-septième siècle, dans une lignée familiale québécoise.