Objective   To assess the proportion of genotypes of CASRA 986S gene polymorphism, and to investigate if the polymorphism of CASRA986S gene is associated with bone mineral density(BMD)in premenarehe Chinese girls.

  Methods   152 healthy premenarche girls of Han ethic(9~11.5y)were recruited.BMD and BM Cat the lumber spine(L1-L4), proximal femur, and total body were measured by DXA; Allele-specific PCR was used to amplify A986Spolymorphisms of the CASR gene.

  Results   The proportions of genotype AA, AS and SS of CASRA 986S gene were 91.44% 7.89% and 0.67%, respectively.The values of bone mass and bone marker in the subjects with the Sallele decreased by 5% (TBBMD), 10% (TBBMC) and 4.6% (L1-L4L SBMD)and 3.5% in Ostocalcin as compared with those without the Sallele(P < 0.01, respectively).The differences in BMD and BM Cbetween subjects with and without the Sallele remained(P < 0.01)even including the terms of age, height, weight, calcium intake, fat mass, lean mass and physical activity in the general liner model.

  Conclusion   Significant association exists between a common polymorphism and bone mineral density in prelnenarehe Chinese girls.The Sallele of A986S polymorphism is also a potential predisposing factor of low bone mineral density.