Study On The Assiociation Of Estrogen Receptor Gene Polymorphism And Developmental Dislocation Of The Hip

ObjectiveDevelopmental dislocation of the hip(DDH) is one of the most common limb malformations in orthopedics. The prevalence of DDH varies according to racial and geographic parameters and is greater in whites than blacks; and is about 1.10—3.80 %o in our country;and is greater in girls than boys,ratio about 1: 4.75 .In the early 80 ' s , there are previous reports with association between HLA and DDH throughout the world.No reports can be found on association between DDH and estrogen receptor gene(ER) abroad.There is a lot of study on bone mineral denisty and estrogen receptor genes in our country in recent years , but no reports was found association between DDH and estrogen receptor gene. To investigate the relationship between DDH and estrogen receptor gene,we choose 48 patients and 48 normal control to study . Genomic DNA was extracted from their blood cells , XbaⅠ and PvuⅡ polymorphism of ER gene were studied by polymenrase chain reaction estriction frgment length polymorphism(PCR-RFLP) .Methods1. Study population: A total of 48 DDH patients composed of experimental group . They was supplied by pediatric surgery department in the Qi Lu Hospital of Shan Dong University. Each patient with DDH showed typical clinical manifestaLion and diagnosed by X rays and operation. While 48 normal individuals as controlled group.2. Isolation of Genomic DNA : 2ml peripheral venous bloods were drawn from all the subjects, and anticoagulanted by EDTA. Genomic DNA was extracted from white blood cells with EZ-10 Spin Column Blood Genomic DNA Minipreps Kit according to the standard procedures.The purified DNA was resolved in buffer in -20°.3 . The primers used to determine the Xbal and PvuII polymorphism of ER gene were:forward, 5' -CTGCCACCCTATCTGTATCTTTTCCTATTCTCC-3' ;reverse, 5' -TCTTTCTCTGCCACCCTGGCGTCGATTATCTGA-3' .4. PCR .Genomic DNA was amplified using polymerase chain reaction (PCR). The condition of PCR cycle were: denaturation at 94°C for 5 min followed 30 circles of (1) denaturation at 94°C for 30 s; (2)annealing at 6TC for 40 s; (3) extension at 72°C for 90s ; (4) extension at 72°C for 10 min was performed after PCR cycle.5. After PCR amplification for ER gene ,the PCR products will be digested with restriction endonuclease, Xbal and PvuII at 37°C for at least three hours . Genotypes of the Xbal and PvuII polymorphism will be separated in 1 % agrosegel electrophoresis and visualized by ethidium bromide staining.6 . Statistical Analysis: To determine whether the proportions observed in our data were those to be expected in a random mating equilibrium population,they were explored using x 2 method. A Pvalue less than 0.05 was considered statistically significant.ResultsXbal polymorphisim of estrogen receptor gene is not associated with developmental dislocation of the hip(p > 0.05) ; while PvuII polymorphisim of estrogen receptor gene is significantly associated with developmental dislocation of the hip(p < 0.05). ConclusionsPvuII polymorphisim of estrogen receptor gene is significantly associated with developmental dislocation of the hip , it implies that the difference in ER genotypes among individuals might influence the development of DDH.