Genetic Analysis Of The Candidate Genes Responsible For Non-syndromic Cleft Lip With Or Without Cleft Palate In Chinese People

Objective:Cleft lip with or without cleft palate (CL/P) is a common congenital anomaly. Birth prevalences are consistently higher in Asian populations than in populations of European descent. About 70% of cases are nonsyndromic (NS) in which the affected individual has no other abnormalities. NSCL/P is thought to be multifactorial in etiology, with evidence indicating that genetic, environmental, and developmental determinants may all play a role. A number of genetic loci such as TGFA, RARA, BCL-3, F13A have shown positive linkage or association results with regard to oral-facial clefting in European Caucasian populations. The first published positive association with oral-facial clefts was a population based association between CL/P and a Taql restriction site polymorphism in the transforming growth factor α locus. The TGFA association with CL/P has since been replicated in several studies, but several other studies have failed to confirm the association. In addition to TGFA loci, Prior studies have implicated an involvement of the GABRB3 gene in cleft palate in mice and its homolog in humans. There are ,however,still controversity of the effect on the predisposition of this malformation.Therefore, it is of interest to determine whether the CL/P etiological factors in Asian populations differ from those in white popula-tions. The purpose of the present study was to investigate whether or not the transforming growth-factor alpha(TGFA) gene and gammaaminobutyrate type A receptor beta3 subunit gene (GABRB3) are associated with nonsyn-dromic cleft lip with or without cleft palate(NSCL/P) in the Chinese Han population.Methods:1. Whole blood (76 cases,60controls) was collected for genetic analysis and was processed with a DNA-isolation kit following manufacturer's instructions (PUREGENE DNA Purification Kit, Gentra).2.TGFA/Tag I typing was carried out by digesting the locus specific polymerase chain reaction amplified products with alleles specific TagI restriction enzyme(PCR-RFLP) in the patients with NSCL/P and healthy Chinese subjects as control.The variants were characterized in case and control populations by x analysis. Heterozygous parents with an affected child were analysed through case-parental control study from transmitted disequilibrium test(TDT) . The variants were examined in the NSCL/P patients with and without family history by x2analysis.3.An intragenic microsatellite marker named GABRB3 CA was selected for GABRB3 gene.Polymerase chain reactions were carried out in a 50 u L final volume.The denatured products were separated by 6% nondenaturing polyacrylamide gel electrophoresis and visualized by silver staining.The sequence variants were examined by x2 analysis.Results:LCI allele frequency was93.3% ,and C2 allele frequency was 6.7% in the...