Effects of Differences in Polymorphism of Gene Encoding Enzyme Faenesyl Diphosphate Synthase (FDPS), rs2297480, on Bone Mineral Density and Biochemical Markers of Bone Turnover in Thai Postmenopausal Women
Thawee Songpatanasilp MD, MSc*, Suwannee Chanprasertyothin MSc**
Affiliation : * Orthopaedic Oncology and Bone Metabolism Unit, Department of Orthopaedics, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand ** Endocrinology laborarory, Faculty of medicine, Rama hospital, Bangkok, Thailand
Objective : The purpose of this study was to find the frequency distribution of a SNP rs2297480 of the human FDPS gene and
its influences on BMD and bone turnover markers in postmenopausal Thai women who never-use any anti-osteoporotic
drugs.
Material and Method: One hundred and thirty-five postmenopausal women at the age of 40 or over, and having been
menopause for at least 2 years were enrolled in the present study. The patients having chronic medical conditions and having
a fracture in any bone within 3 months were excluded. All of the subjects never used any anti-osteoporotic drugs, steroid
hormones and warfarin. Bone mineral density and bone turnover markers including N-MID osteocalcin and β-CTx were
performed. Blood samplings for FDPS genotyping were collected and examined for rs2297480 SNP.
Results : The mean age of the patients was 60.4 (43-79) years old. The mean BMD T-score at all three major sites (Femoral
neck, Lumbar spine, and Total hip) fell in the criteria of osteopenia. Twenty-four per cent of patients were diagnosed as
osteoporosis (BMD T-score at one of three major sites was equal to or below -2.5 SD). One hundred and thirty-five patients
whose data of rs2297480 SNP were defined as follows: AC genotype (45.1%), CC genotype (41.6%) and AA genotype
(13.3%). Comparing among these three genotypes of rs2297480 SNP, the results showed no differences of BMD and BMTs
among them. The absolute BMD after being adjusted to the same level of age and body weight and also β-CTx and N-MID OC
between the group of AA + AC and the CC genotypes were also compared. No factors were statistically significant.
Conclusion : This is the first research investigating the gene FDPS rs2297480 SNP in postmenopausal Thai women. The
frequency distribution of this SNP is the same as the distribution of the Asians but different from the Caucasians’. There are
some small trends in the lower baseline of BMD at femoral neck and total hip in CC genotype group of these postmenopausal
women although the results are not statistically significant. The effect of rs229748 SNP did not contribute to the baseline of
BMD as well as the baseline of bone turnover markers before the treatment.
Keywords : FDPS gene, rs2997480, Bisphosphonates, Bone mineral density, Bone turnover markers
