Background: Nose shape might be environmentally influenced; however, there are evidences of it being inheritedin simple Mendelian dominant‑recessive patterns. In such instance, a nose can be broad or narrow with respect toits wideness in comparison to the intercanthal bridge. Therefore, this study was aimed at determining the inheritancepattern of nose shape in the bid to ascertain its usability in parentage determination.
Methods: Three hundred andthirty‑seven subjects from 101 families comprising 202 parents and 135 offspring were recruited for this study. Thefamilies were randomly selected from within Port Harcourt by a multistage sampling technique. Their nose shape wereobserved physically in the father, mother, and at least a child in each family and documented. The offspring traits weretabularized in patterns of parental combinations (when both parents’ nose are broad, both parents’ nose are narrow,and a combination of broad and narrow). SPSS IBM (r) version 20 was used to analyze the data. Descriptive statisticsand test for association between sex and nose shape was carried out by Chi‑square analysis and the conformanceto Mendelian inheritance pattern was analyzed using Mendelian Chi‑square gene distribution model.
Results: Broadnose shape was more frequent with 298 (88.4%) when compared to narrow nose shape (11.6%). About 46.9% ofmales had broad nose against 41.5% for females. However, this distribution was not observed to follow any sexualpreference (χ2 = 0.141, P > 0.932). The observed and expected outcome were tested for significance on the assumptionthat offspring outcome conforms to Mendelian simple dominant‑recessive monohybrid cross; conformance was observed.
Conclusion: The distribution of nose shape was observed to be genetically determined and follows Mendelian singlegene dominant‑recessive pattern with the allele for narrow nose dominant over the allele for broad nose. This resultcan be used for preliminary screening in parentage dispute. It can also be useful in forensic and genetic studies.
Keywords: Mendelian pattern, Nigerians, nose shape, Port Harcourt, trait
