Genome-wide analyses of nonsyndromic cleft lip with or without palate identify 20 new risk loci in the Chinese Han population

Multi-ancestry Genome Wide Association Study Meta-analysis of Non-syndromic Orofacial Clefts

Non-syndromic orofacial clefts (NSOC) are common craniofacial birth defects, and result from both genetic and environmental factors. NSOC include three major sub-phenotypes: non-syndromic cleft lip with palate (NSCLP), non-syndromic cleft lip only (NSCLO) and non-syndromic cleft palate only (NSCPO), NSCLP and NSCLO are also sometimes grouped as non-syndromic cleft lip with or without cleft palate (NSCL/P) based on epidemiology. Currently known loci only explain a limited proportion of the heritability of NSOC. Further, differences in genetic susceptibility among the sub-phenotypes are poorly characterized. We performed a multi-ancestry GWAS meta-analysis on 44,094 individuals (9,381 cases, 28,510 controls, 2042 case-parent trios and 18 multiplex pedigrees) of East Asian, European, Latin and South American, and African ancestry for both NSOC and subtypes. We identified 50 loci, including 11 novel loci: four loci ( CALD1 , SHH , NRG1 and LINC00320 ) associated with both NSOC and NSCL/P, two loci ( NTRK1 and RUNX1 ) only associated with NSOC, four loci ( HMGCR , PRICKLE1 , SOX9 and MYH9 ) only associated with NSCL/P and one locus ( ALX1 ) specifically associated with NSCLO. Five of the novel loci are located in regions containing genes associated with syndromic orofacial clefts ( SHH , NTRK1, CALD1, ALX1 and SOX9 ); seven of the novel loci are located in regions containing genes-implicated in craniofacial development ( HMGCR, SHH, PRICKLE1, ALX1, SOX9, RUNX1, MYH9 ). Genetic correlation and colocalization analyses revealed an overlap between signals associated with NSCLO, NSCPO and NSCLP, but there were also notable differences, emphasizing the complexity of common and distinct genetic processes affecting lip and palate development.

Genetic association and functional validation of ZFP36L2 in non-syndromic orofacial cleft subtypes

BACKGROUND

Non-syndromic orofacial cleft (NSOC) is one of the most common craniofacial malformations with complex etiology. This study aimed to explore the role of specific SNPs in ZFP36L2 and its functional relevance in zebrafish models.

METHODS

We analyzed genetic data of the Chinese Han population from two previous GWAS, comprising of 2512 cases and 2255 controls. Based on the Hardy-Weinberg Equilibrium (HWE) and minor allele frequency (MAF), SNPs in the ZFP36L2 were selected for association analysis. In addition, zebrafish models were used to clarify the in-situ expression pattern of zfp36l2 and the impact of its Morpholino-induced knockdown.

RESULTS

Via association analysis, rs7933 in ZFP36L2 was significantly associated with various non-syndromic cleft lip-only subtypes, potentially conferring a protective effect. Zebrafish embryos showed elevated expression of zfp36l2 in the craniofacial region during critical stages of oral cavity formation. Furthermore, Morpholino-induced knockdown of zfp36l2 led to craniofacial abnormalities, including cleft lip, which was partially rescued by the addition of zfp36l2 mRNA.

CONCLUSION

Our findings highlight the significance of ZFP36L2 in the etiology of NSOC, supported by both human genetic association data and functional studies in zebrafish. These results pave the way for further exploration of targeted interventions for craniofacial malformations.

Genome-wide meta-analyses identify five new risk loci for nonsyndromic orofacial clefts in the Chinese Han population

BACKGROUND

Nonsyndromic orofacial clefts (NSOFCs) are the most common craniofacial birth malformations in humans and are generally classified as nonsyndromic cleft lip with or without cleft palate (NSCL/P) and nonsyndromic cleft palate only (NSCPO). Genome-wide association studies (GWASs) of NSOFCs have demonstrated multiple risk loci and candidate genes; however, published risk factors are able to explain only a small fraction of the observed NSOFCs heritability.

METHODS

Here, we performed GWASs of 1615 NSCPO cases and 2340 controls, and then conducted genome-wide meta-analyses of NSOFCs, totaling 6812 NSCL/P cases, 2614 NSCPO cases, and 19,165 controls from the Chinese Han population.

RESULTS

We identify 47 risk loci with genome-wide pmeta -value <5.0 × 10-8 , 5 risk loci (1p32.1, 3p14.1, 3p14.3, 3p21.31, and 13q22.1) of which are new. All of the 47 susceptibility loci conjointly account for 44.12% of the NSOFCs' heritability in the Chinese Han population.

CONCLUSION

Our results improve the comprehending of genetic susceptibility to NSOFCs and provide new views into the genetic etiology of craniofacial anomalies.