Complex segregation analysis of quantitative dermatoglyphic traits in five Indian populations

Dermatoglyphics is widely used as a genetically determined trait in anthropogenetics although the genetic nature of its inheritance is still inconclusive, due to the lack of any established genetic model to resolve the existing inconsistencies in the literature. However, advanced statistical packages for complex segregation analyses are available and the aim of the present study is to determine the mode of dermatoglyphic trait inheritance in five different ethnic populations.

Five hundred families (2435 individuals) of two generations were used for principal component analysis, familial correlation and segregation analysis (package MAN-5).

The similarity of three factors suggests a common internal structure. Significant familial correlation (except spouse) indicates the involvement of a familial component in the variation of dermatoglyphic traits. Segregation analyses suggest the transmission of a genetic effect in the families which follows the Mendelian model and confirms a major gene effect on factor 1 and factor 2 with two co-dominant alleles. There is no evidence of a major gene effect or environmental effect on factor 3 (a-b ridge counts). The nature of transmission and trait variance (H2) strongly supports the existence of a common nature of dermatoglyphic trait inheritance in populations, irrespective of ethnic and geographic area.

Major gene involvement in finger dermatoglyphics according to Mendelian models is confirmed.