Inheritance Pattern of Lip Prints among Nigerians
Introduction: Lip prints are normal wrinkles and grooves running between the inner labial mucosa and the outer skin of lips. The probability of an offspring inheriting certain traits from parents could be easily appreciated and predicted if the inheritance pattern is established. Aim: This study was aimed at investigating the inheritance pattern lip prints among Nigerians. Methods: A total of 450 subjects comprising of 150 families (father, mother and a child) were conveniently sampled from across Rivers State. Oghenemavwe and Osaat digital fingerprint capture technique were adopted for this study. The lips (upper and lower) were then divided lip into four quadrants (URQ, ULQ, LRQ, LLQ) to independently access and observe the predominant lip print patterns in each quadrant using Suzuki and Tsuchihashi’s classification (Types; I, I’, II, III, IV, and V). Using XLSTAT Statistical package (Addinsoft Version 2015.4.01.21575) Chi-square analysis was used to determine the association. P<0.05 (at 95% confidence level) was taken to be significant. Lip prints of the parents (as a single group) were tabulated and their possible combination outcome (by crosses) in their offspring was established using Excel sheet. Results: The total distribution of lip prints between parents and offspring showed [Type I (Parents 315, 26.3%; Offspring 133, 22.2%), Type I’ (Parents 210, 17.5%; Offspring 105, 17.5%), Type II (Parents 290, 24.2%; Offspring 131, 21.8%), Type III (Parents 191, 15.9%; Offspring 131, 21.8%), Type IV (Parents 186, 15.5%; Offspring 87, 14.5%), Type V (Parents 8, 0.7%; Offspring 13, 2.2%) ] which had significant association (P = 0.002). Observation of the inheritance pattern of lip prints revealed almost impracticable predictability. Conclusion This study suggests that the inheritance pattern of lip prints were inconsistent with Mendelian fashion (dominant-recessive) rather, lip prints exhibit polygenic inheritance pattern with incomplete penetrance (reduced penetrance).