Role of COL9A1 genetic polymorphisms in development of congenital talipes equinovarus in a Chinese population.

Talipes equinovarus is a common congenital deformity. COL9A1 polymorphisms are associated with the development of articular cartilage-related diseases. In the current study, we evaluated the relationship between COL9A1 rs1135056, rs35470562, and rs592121 genetic polymorphisms and risk of congenital talipes equinovarus. Between January 2013 and July 2015, 87 children with congenital talipes equinovarus and 174 control subjects were recruited from the Fourth People's Hospital of Shaanxi and the First Hospital of Yulin. Genotyping of COL9A1 rs1135056, rs35470562, and rs592121 was performed using polymerase chain reaction-restriction fragment length polymorphism. Using conditional regression analysis, the AA genotype of COL9A1 rs35470562 was found to be significantly associated with increased risk of congenital talipes equinovarus compared to the GG genotype [odds ratio (OR) = 2.60, 95% confidence interval (CI) = 1.06-6.32]. In addition, under a recessive model, rs35470562 AA carriers were observed to be at higher risk for this condition in comparison to individuals with GG or GA genotypes (OR = 2.23, 95%CI = 1.03-5.04). However, no significant relationship was established between the COL9A1 rs1135056 and rs592121 polymorphisms and congenital talipes equinovarus in any of the genetic models tested. In conclusion, our results indicate that the COL9A1 rs35470562 variant may contribute to congenital talipes equinovarus susceptibility in the Chinese population examined.