Association between Genetic Polymorphism in Interferon Regulatory Factor 6 (IRF6) & Non-Syndromic Cleft Lip & Palate Cases in Central Indian Population

BACKGROUND Orofacial clefts can transpire either, as part of complex malformation syndromes, or as an isolated entity, also called non-syndromic cleft. Cleft lip with or without cleft palate (CL/P), collectively termed oral clefts, are the second most commonly observed birth defects among newborns after congenital heart defects. We wanted to investigate the association between genetic polymorphism in Interferon Regulatory Factor 6 (IRF6) & non-syndromic cleft lip and palate (CL/P) cases in Central Indian population. METHODS In this cross-sectional observational study, the sample comprised of Group 1: 66 individuals and 7 affected families with non-syndromic CL/P; and Group 2: 30 normal individuals and 10 normal families. 5 ml blood sample was collected from each individual following proper surgical protocol using disposable syringes, in blood tubes containing EDTA, with proper labelling and coding for further identification. DNA extraction was done by phenol chloroform extraction protocol and amplification was done using Polymerase Chain Reaction (PCR). Genotyping for the IRF6 polymorphism was completed by restriction digestion of PCR products, also called Restriction Fragment Length Polymorphism (RFLP). RESULTS The correlative comparison between GG and GA polymorphism in IRF6 gene between affected cases and normal patients shows highly significant value. The comparison between GG & GA polymorphism shows that GG polymorphism is significantly higher in affected cases compared to Group 2. While GA polymorphism is significantly low or decreased in non-syndromic CL/P patients when compared to control group. CONCLUSIONS GG polymorphism is more frequently associated with non-syndromic CL/P as compared to GA polymorphism.