Evaluating the prevalence of five genetic traits of simple inheritance in association with the distribution pattern of ABO and rhesus phenotypes among families in Calabar, Nigeria

Abstract

Morphological and behavioral genetic traits of simple inheritance indicate ethnic variation and have been widely employed in population variation studies. Five selected genetic traits of simple inheritance, ABO and Rh (D) blood phenotype was investigated to establish the inheritance pattern, prevalence and to assess association between the traits, ABO rhesus phenotypes and gender of 45 unrelated families living in Calabar. Blood group O was the most prevalent (55.2%) followed by B (21.6%), A (18.8%) while the least was AB (4.4%). The majorities (91.6%) were Rh (D) positive and 8.4% were Rh (D) negative. The frequency of the 5 genetic traits were earlobe (69.2% free earlobe, 30.8% attached earlobe), hand-clasping (51.6% right hand-claspers, 48.4% left hand-claspers), dimples (21.2% had facial dimples, 78.8% had no dimples), mid-digital hair (presence in 92%, absence in 8%) and tongue rolling (48.4% rollers, 51.6% non-roller). There was association between earlobe and blood group, sex and hand clasping, sex and facial dimples and between tongue rolling and sex. Chi-square analysis of the inheritance pattern of these genetic traits provides strong evidence for a familial and probably a genetic component in the control of these traits. The pattern also showed that the traits are inherited in dominance versus recessive manner.