Associations of ABCA4 and MAFB with Nonsyndromic Cleft Lip with or without Cleft Palate in a Northeastern Chinese Population

Polymorphisms of ATP-Binding Cassette, Sub-Family A, Member 4 (rs560426 and rs481931) and Non-Syndromic Cleft Lip/Palate: A Meta-Analysis

Background: A number of genes are associated with the incidence of non-syndromic cleft lip/palate (NSCL/P). Studies have shown a significant association between polymorphisms of ATP-binding cassette, sub-family A, member 4 (ABCA4) with the risk of NSCL/P. The present meta-analysis assessed the association between ABCA4 polymorphisms (rs560426 and rs481931) and the NSCL/P risk by reviewing case-control studies. Methods: Four databases (Scopus; Cochrane Library; Web of Science; and PubMed) were searched for articles published up to June 2020. The Review Manager 5.3 software was used to calculate the crude odds ratio (OR) and 95% confidence interval (CI). Both subgroup analyses for ethnicity and source of controls and a meta-regression related to publication year were conducted. Results: Of 94 retrieved studies, 12 were analyzed in this meta-analysis (2859 NSCL/P patients and 3792 controls for ABCA4 rs560426 polymorphism and 1333 NSCL/P patients and 1884 controls for ABCA4 rs481931 polymorphism). Overall, there was no significant association between both polymorphisms and the risk of NSCL/P. However, subgroup analysis demonstrated that there was a higher risk of NSCL/P for specific models: the allelic model (OR = 1.13; p = 0.03), the homozygote model (OR = 1.53; p = 0.04), and the recessive model (OR = 1.30; p = 0.03) in the Asian ethnicity for the rs560426 polymorphism. Conclusion: The findings confirmed that the NSCL/P risk was significantly associated with the G allele and GG genotype of rs560426 polymorphism but not for rs481931 polymorphism. There were no associations between both polymorphisms (rs560426 and rs481931) and the NSCL/P risk in those of European descent and the mixed ethnicities.

Environmental mechanisms of orofacial clefts

Orofacial clefts (OFCs) are among the most common birth defects and impart a significant burden on afflicted individuals and their families. It is increasingly understood that many nonsyndromic OFCs are a consequence of extrinsic factors, genetic susceptibilities, and interactions of the two. Therefore, understanding the environmental mechanisms of OFCs is important in the prevention of future cases. This review examines the molecular mechanisms associated with environmental factors that either protect against or increase the risk of OFCs. We focus on essential metabolic pathways, environmental signaling mechanisms, detoxification pathways, behavioral risk factors, and biological hazards that may disrupt orofacial development.

Association between MAFB rs17820943 and rs6072081 polymorphism and risk of nonsyndromic cleft lip with or without cleft palate: a meta-analysis

While there have been previous studies examining the relation between the rs17820943 and rs6072081 polymorphisms in the v-maf musculoaponeurotic fibrosarcoma oncogene homolog B (MAFB) gene and rates of nonsyndromic cleft lip with or without cleft palate (NSCL/P), at present the results of these studies have been inconsistent. This meta-analysis therefore aimed to conduct a more robust assessment of the association between the MAFB rs17820943 and rs6072081 polymorphisms and NSCL/P risk. The Embase, Web of Science, PubMed, the China National Knowledge Internet (CNKI), and Wanfang databases were systematically searched to identify relevant studies. In total, five studies incorporating 2769 patients and 2885 controls were identified assessing the rs17820943 polymorphism and three studies incorporating 1242 patients and 1310 controls assessing the rs6072081 polymorphism were identified. This analysis revealed the MAFB rs17820943 and rs6072081 polymorphisms to be linked to a significantly reduced NSCL/P risk (rs17820943: C vs T: OR=0.76, 95% CI=0.70-0.82; CC vs CT: OR=0.75, 95% CI=0.67-0.85; CC vs TT: OR=0.58, 95% CI=0.49-0.67; CC+CT vs TT: OR=0.67, 95% CI=0.59-0.77; CT+TT vs CC: OR=1.43, 95% CI=1.28-1.60; rs6072081: A vs G: OR=0.77, 95%CI=0.68-0.86; AA vs AG: OR=0.76, 95%CI=0.64-0.90; AA vs GG: OR=0.58, 95%CI=0.45-0.74; AA+AG vs GG: OR=0.68, 95%CI=0.54-0.84; AG+GG vs AA: OR=1.40, 95% CI=1.19-1.65). The results of the present meta-analysis indicate that in an East Asian population, for both rs17820943 and rs6072081 were associated with NSCL/P.