Transmission Disequilibrium Test Of HOXD8 Gene Polymorphism And Congenital Dislocation Of The Hip

ObjectiveCongenital dislocation of the hip (CDH) is one of the most common limb malformations in orthopedics. The prevalence of CDH varies according to racial and geographic parameters and is greater in whites than blacks; and is about 0.9-3.8%. in our country; and is greater in girls than boys, ratio about 1:4.75. In the early 80s, there are previous reports with association between HLA and CDH throughout the world. No reports can be found on association between CDH and HOX abroad. There is a study on CDH and HOXD9 genes in our country 2002, but which found no association between CDH and HOXD9. Their results may be false negative because their case number is not enough. To further investigate the association between CDH and HOX genes, we choose microsatellite marker in HOXD8 gene, and add case number.Methods1. Subject and specimens A total of 101 CDH family was supplied by orthopedics in the Second Afflicted Hospital of China Medical University. Each patient with CDH showed typical clinical manifestation and was diagnosed by X - rays and operation. Venous bloods weredrawn from all the subjects, and genome DNA was extracted from white blood cells according to the standard procedures.2. PCR amplification Information Using a microsatellite polymorphism located in the 3 ' untranslated region of the HOXD8 gene, microsatellite marker was obtained from http://www. gdb. org. DNA was amplified in 251 PCR reaction. Samples were amplified in a PTC200 thermal cycler with an initial denaturation at 94 C for 10 min followed by 35 cycles of denaturation at 94 C for 40s, annealing at 55 C for 40s, and extension at 72 C for 40 s, with a final 7 min extension at 12 C. 2% agrose gels examined PCR products.3. Genotyping PCR products were run on 6% denaturing poly-acrylamide gel containing 7 mol/L urea for 2. 5h. The gels were stained by silver.4. Statistical analysis transmission disequilibrium test ( TDT) was performed by SAS software.Results1. 16 alleles were detected at 101 CDH families, each named al-lele 1-16.2. For allele 4, transmission number is 19, no transmission -number is 6, x2=6.461, P= 0.011. Transmission disequilibrium was found between CDH and allele 4.Conclusion1. 16 alleles can be detected in CDH families of the Chinese population.2. The association between CDH and HOXD8 gene in CDH families of the Chinese population.