Inheritance of digital arches in humans: is the major gene fully penetrant?

From the fingertip pattern analysis of 125 families with 376 children from Velanadu Brahmin and 100 families with 286 children from Telaganya Brahmin caste sects of Andhra Pradesh, India, the occurrence of an arch on at least one of the ten finger tips is shown to be aggregated in families. The mode of aggregation is in conformity with a major dominant gene with 0.28 chance of penetrance. This is to some extent contradictory to the result published from the analysis of a single Habbanite Jewish pedigree. Some implications of this discordant result are also discussed.