Genetics of dermatoglyphic patterns on palms

SUMMARY Genetics of palmar dermatoglyphics have been investigated on the basis of a topological classification of dermal ridge patterns. A study was undertaken in a sample of 201 Polish families, comprising 187 pairs of parents and 666 children. Correlational analysis was performed using an IBM computer. The first step was to establish frequencies of dermatoglyphic characters in the sample and anatomical correlations between various patterns on palms and finger tips. Then, correlation coefficients between relatives were calculated for eighteen dermatoglyphic characters. Further genetical analysis of the data was performed, including estimates of heritability index ( h 2 ), dominance‐recessivity index ( dr )2 and search for the possible influence of sex‐linked genes. The results obtained show that the dermatoglyphic characters on palms vary considerably with respect to the proportions of genetical and environmental components; some of them, like hypothenar H loop, interdigital loop II and triradius t and some quantitative characters, like pattern intensity, have high heritability indices, while the others, like hypothenar distal loop H, radial hypothenar loop H r or z triradii, are almost entirely determined by environmental influences. It was further possible to examine the mode of inheritance of some of the pattern elements. It can be assumed, on a basis of results so far obtained, that some dermatoglyphic characters like loops Ĥ and II and presence of triradius t may be determined mainly by single genes those for the loops being in homozygous recessive form.