Two Single-Nucleotide Polymorphisms in the DKK1 Gene Are Associated with Developmental Dysplasia of the Hip in the Chinese Han Female Population

AIMS: Developmental dysplasia of the hip (DDH) is a common congenital or acquired skeletal disease characterized by subluxation, dislocation, or dysplasia of the hip joint. This study aimed to explore the potential impact of Dickkopf-1 (DKK1) gene polymorphisms on embryonic hip joint development and the course of DDH. METHODS: One hundred ninety-two unrelated Chinese Han female DDH patients and 191 unrelated, healthy, ethnically matched female controls were recruited and genotyped for two tag single-nucleotide polymorphisms (SNPs) of DKK1 using the Sequenom method. RESULTS: One of the two DKK1 tag SNPs, rs11001560, was not shown to be significantly statistically different in allele frequency between DDH patients and control groups (χ(2)=0.898, df=1, p=0.343). However, a significant difference in genotype distribution was observed (χ(2)=21.987, df=2, p<0.0001). For SNP rs1569198, significant differences were observed in both allele frequency and genotype distribution between the DDH group and control group (χ(2)=31.484, df=1, p<0.0001 and χ(2)=30.323, df=2, p<0.0001). The A allele frequency of rs1569198 has a significant association to increased risk of DDH development (odds ratio [OR]=3.032, 95% confidence interval [95% CI]: 2.034-4.519). CONCLUSION: In conclusion, the association between two tag SNPs of the DKK1 gene and DDH development reached statistical significance in our study population; the results of our genetic association analysis indicated that DKK1 may be a good candidate responsible for DDH development in the Chinese Han female population.