Polymorphism

See Also

Description

Danforth (1) suggested that complete absence of hair on the middle segment of the fingers is a simple recessive trait in man, and there can be no doubt that the condition is inherited. Danforth reported a study of 80 families with 178 children. Bernstein and Burks (2) extended Danforth's study, but concluded that more than a simple Mendelian pair of genes were involved. They offered the hypothesis of five multiple alleles, D0, D1,D2,D3, D4 (listed in order of increasing dominance) where the subscripts correspond to the number of fingers having mid-digital hair. Individuals of the genotype D0D0 would have no mid-digital hair.

Discussion

Incidence of Mid-digital Hair in Various Populations

From: Genetics And The Races of Man, William C. Boyd. Little Brown and Company, Boston (1950)

PopulationPlace# Males # Females % with MDH Male% with MDH Female
RussiansMoscow11611564.645.3
Georgians (West)Tiflis11912449.643.5
Georgians (East)Tiflis627156.433.8
RussiansKharkov5811256.950.9
Egyptians (Copts)Cairo555265.546.2
Egyptians (Moslems)Cairo22820345.636.4
Egyptians (Copts)Assiut20221552.553.0
Egyptians (Moslems)Assiut5o5368.o28.3
BasquesSan Sebastian255364.073.6
Syrians (Moslems)Boarij686177.955.7
Syrians (Christians)Meshghara901668.950.0
Syrians (Moslems)Meshghara1296658.r54.5
ArmeniansBeyrouth and Ghazir16517262.461.6
Arabs (Moslems)Baghdad23313267.450.7
Arabs (Christians)Baghdad481464.650.7
JewsBaghdad6913671.059.6

Links


1. Danforth, C. H., A. I. P. A., 4, 189-204 (1921)

2. Bernstein, M. M., and B. S. Burks, Heredity, 33, 45-53 (1942)