Asymmetry and pattern polarization of digital dermal ridges among the Ogoni people of Nigeria

Dermal ridges express patterns of asymmetry and polarization across the fingers that can characterize human populations. They are also known somatic markers of teratogenic insults. This study documents the asymmetry and pattern polarization of dermal ridges among the Ogoni people of Nigeria. Ink prints of the fingers were obtained from 406 apparently healthy Ogoni subjects and dermal ridge pattern types of whorls, arches, ulnar loops and radial loops identified and their pattern of polarization across the ten digits established for each hand in each sex. Ulnar loops polarized preferentially to digits III –V; arches to digits I-II; whorls to digits I, II, and IV; and radial loops to digits II. Female subjects had higher counts of arches (P <0.001), radial loops and ulnar loops (P>0.05) than the males, while male subjects had higher counts of whorls (P<0.01) than the females. The findings of this study form useful baseline data for subsequent longitudinal cytogenetic studies on the Ogoni people.