Haplotype and Haplotype-Environment Interaction Analysis Revealed Roles of SPRY2 for NSCL/P among Chinese Populations

Genetics and signaling mechanisms of orofacial clefts

Craniofacial development involves several complex tissue movements including several fusion processes to form the frontonasal and maxillary structures, including the upper lip and palate. Each of these movements are controlled by many different factors that are tightly regulated by several integral morphogenetic signaling pathways. Subject to both genetic and environmental influences, interruption at nearly any stage can disrupt lip, nasal, or palate fusion and result in a cleft. Here, we discuss many of the genetic risk factors that may contribute to the presentation of orofacial clefts in patients, and several of the key signaling pathways and underlying cellular mechanisms that control lip and palate formation, as identified primarily through investigating equivalent processes in animal models, are examined.

Association of Genetic Polymorphisms of GREM1 Gene with Susceptibility to Non-Syndromic Cleft Lip with or without Cleft Palate in an Iranian Population

Background: Nonsyndromic cleft lip with or without cleft palate (NSCL/P) is common congenital birth anomaly with multifactorial etiology. The GREM1 gene has been proposed to play a role in oral clefts development.Objective: The aim of the present study was to evaluate the correlation between GREM1 polymorphisms and the risk of NSCL/P in an Iranian population.Methods: Genotyping of rs7162202, rs12915554, rs3743105, rs1129456, and rs10318 polymorphisms of GREM1 gene in 150 NSCL/P and 152 healthy subjects was determined by the PCR-RFLP or T-ARMS-PCR.Results: The findings showed that the rs12915554 variant significantly increased the risk of NSCL/P in heterozygous (OR = 4.20, 95%CI = 2.46-7.11, p < 0.0001, AC vs AA), and allele (OR = 3.17, 95%CI = 2.00-5.08, p < 0.0001, C vs A) genetic models. The rs3743105 polymorphism was correlated with reduced risk of NSCL/P in heterozygous (OR = 0.49, 95%CI = 0.29-0.83, p = 0.008, AG vs GG) and dominant (OR = 0.54, 95%CI = 0.33-0.89, p = 0.018, GA + AA vs GG) genetic models. The rs1129456 variant was positively associated with the risk of NSCL/P in heterozygous (OR = 2.91, 95%CI = 1.12-7.38, p = 0.028, AT vs AA) and allele (OR = 2.80, 95%CI = 2.80-6.95, p = 0.031, T vs C). The rs10318 polymorphism significantly reduced NSCL/P risk in homozygous (OR = 0.20, 95%CI = 0.06-0.67, p = 0.013, TT vs CC), dominant (OR = 0.57, 95%CI = 0.36-0.91, p = 0.019, CT + CC vs CC), recessive (OR = 0.24, 95%CI = 0.07-0.76, p = 0.031, TT vs CT + CC), and allele (OR = 0.57, 95%CI = 0.38-0.84, p = 0.005, T vs C). No correlation was observed between rs7162202 polymorphism and NSCL/P.Conclusion: The findings support that GREM1 polymorphisms are involved in NSCL/P susceptibility in an Iranian population.

[Association between platelet-derived growth factor-C single nucleotide polymorphisms and nonsyndromic cleft lip with or without cleft palate in Western Chinese population]

OBJECTIVE

To explore the association between two single nucleotide polymorphisms (SNPs), namely, rs4691383 and rs7667857, in the platelet-derived growth factor-C (PDGF-C) gene, the genotypes, environmental exposure factors, and nonsyndromic cleft lip with or without cleft palate (NSCL/P) in Western Chinese population.

METHODS

A total of 268 case-parent trios were selected, and two SNPs (rs4691383 andrs7667857) were genotyped by using polymerase chain reaction and restriction enzyme fragment length polymorphic method and direct sequencing method. Hardy-Weinberg equilibrium, linkage disequilibrium test, transmission disequilibrium test, and haplotype analysis were conducted to analyze the data. Meanwhile, the questionnaires on the epidemiology of cleft lip and palate filled by the included samples were collected, and the interaction between the genotypes of the two SNPs and environmental exposure factors was assessed by conditional logistic regression.

RESULTS

The A allele at rs4691383 and the G allele at rs7667857 of PDGF-C gene were over-transmitted for NSCL/P (P<0.05). No interaction effect was observed between the three environmental exposure factors (history of smoking/passive smoking, folic acid supplementation, and long-term inhalation of harmful environmental gases) and the PDGF-C genotypes among NSCL/P (P>0.05).

CONCLUSIONS

The rs4691383 and rs7667857 at PDGF-C gene are closely related to the occurrence of NSCL/P in Western Chinese population. However, the interaction between environmental exposure factors and PDGF-C genotypes is not obvious in the occurrence of NSCL/P.