Identification of putative regulatory single-nucleotide variants in NTN1 gene associated with NSCL/P.

Non-syndromic cleft lip with or without cleft palate (NSCL/P) is a common polygenetic disease. Although genome-wide association studies (GWAS) identified NTN1 gene as a high-priority candidate of NSCL/P, the comprehensive genetic architecture of NTN1 weren't yet known. Thus, this study aimed to determine full-scale genetic variants of NTN1 for NSCL/P in Chinese Han people. Initially, targeted sequencing of NTN1 gene was performed on 159 NSCL/P patients to identify susceptible single nucleotide polymorphisms (SNPs) associated with NSCL/P. Then, association analysis and burden analysis were separately used to validate the common variants and rare variants identified among large size of samples (1608 NSCL/P cases and 2255 controls). Additionally, NSCL/P subtype association analysis was applied to elucidate the etiology discrepancy of non-syndromic cleft lip with palate (NSCLP) and non-syndromic cleft lip only (NSCLO). Lastly, bioinformatics analysis was performed to annotate and prioritize candidate variants. We found 15 NSCL/P-associated SNPs including rs4791774 (P = 1.10E-08, OR = 1.467, 95% CI: 1.286~1.673) and rs9788972 (P = 1.28E-07, OR = 1.398, 95% CI : 1.235~1.584) originally detected by previous GWASs in Chinese Han ancestry. Four NSCLO risk-associated SNPs and eight specific NSCLP associated SNPs were found. Three SNPs (rs4791331, rs4791774 and rs9900753) were predicted to locate at regulatory region of NTN1. Our study validated the association between NTN1 gene and pathogenesis of NSCL/P and reinforced the hypothesis that NSCLP have a different etiology from NSCLO. We also identified three putative regulatory SNPs in NTN1 gene.

Rs9891446 in NTN1 is associated with right-side cleft lip in Han Chinese population.

OBJECTIVES: This study aimed to reveal the association between single-nucleotide polymorphism of NTN1 and subtypes of non-syndromic cleft lip with or without cleft palate (NSCL/P) in Han Chinese Population. DESIGN: Initially, we selected three single-nucleotide polymorphisms (SNP) (rs4791331, rs4791774 and rs9891446) in NTN1 from previous genetic studies. Then we recruited two Han Chinese cohorts (2004 cases and 1823 controls) and divided cases into subgroups: non-syndromic right-side cleft lip, non-syndromic left-side cleft lip, non-syndromic bilateral cleft lip and non-syndromic cleft lip with palate to further evaluate the associations between the subtypes of NSCL/P and SNPs in NTN1. PLINK and Haploview program were utilized to analyze the data. RESULTS: In the association analysis under additive model, we found that G allele at rs9891446 could specifically increase the risk of right-side cleft lip (P = 0.0073, OR = 1.44, 95%CI: 1.1-1.88), which was consistent with the results of association analysis under genotypic model. CONCLUSION: This study showed that rs9891446 of NTN1 was specifically associated with right-side cleft lip in Han Chinese, which indicates that different subtypes of non-syndromic cleft lip have distinct genetic background.