BACKGROUND: The aim of this study was to investigate whether the TGFA/TGFB3/MSX1 gene polymorphisms and haplotypes lead to individual differences between congenital non-syndromic hearing impairment (NSHI) patients and normal people in a Chinese population and to analyze the risk factors for NSHI.

MATERIAL AND METHODS: Between December 2010 and September 2014, 343 congenital NSHI patients were recruited as cases, and 272 healthy subjects were recruited as controls. Denaturing high-performance liquid chromatography (DHPLC) was used to identify genotypes, SHEsis software was used to conduct gene linkage disequilibrium and haplotype analyses, and regression analysis was performed to identify risk factors for congenital NSHI.

RESULTS: The distribution of genotype frequencies and allele frequencies of TGFA rs3771494, TGFB3 rs3917201 and rs2268626, and MSX1 rs3821949 and rs62636562 were significantly different between the case and the control groups (all P<0.05). TGFA/TGFB3/MSX1 gene rs3771494, rs1058213, rs3917201, rs2268626, rs3821949, and rs62636562 haplotype analysis showed that haplotype CCGTAC and TTACGT might be protective factors (both P<0.001), while TTGCGC might be a risk factor for the normal population (P<0.001). The other risk factors include paternal smoking, advanced maternal age, maternal sickness history, maternal contact with pesticides or similar drugs, maternal abortion history, maternal medication history, maternal passive smoking history during pregnancy, rs3771494 CT, rs2268626 CC and TC, and rs3821949 GG and AG genotypes were risk factors (all P<0.05), while maternal vitamin supplements during pregnancy, rs3917201 GA, rs62636562 TT and CT genotypes were protective factors for congenital NSHI (all P<0.05).

CONCLUSIONS: rs3771494, rs3917201, rs2268626, rs3821949 and rs62636562 might be associated with congenital NSHI.

Keywords: Asian Continental Ancestry Group - genetics, Alleles, Adolescent, Case-Control Studies, Child, Gene Frequency, Genetic Predisposition to Disease, genetic variation, Hearing Loss - genetics, Linkage Disequilibrium, MSX1 Transcription Factor - metabolism, Polymorphism, Single Nucleotide, Transforming Growth Factor alpha - metabolism, Transforming Growth Factor beta3 - metabolism