The difference in bone volume between the mice of two genotypes becomes more prominent at 52 weeks [27] Total body BMD [26] PTHR1 Femoral neck BMD [28–31] No abnormal bone-related phenotypes were reported in PTHR1-deficient mice Eiken syndrome [32] Blomstrand chondrodysplasia [32, 33] CRTAP Osteogenesis imperfecta [34–37] Shortening of long bone segments (particularly the proximal segment of the limb), decreased bone volume/tissue volume ratio, decreased trabecular thickness, decreased trabecular number,

increased trabecular separation, reduced bone formation rate due to a reduction in the mineral apposition rate, and decreased mineralization lag time [35] TDGF1 Ranked first in the prediction of osteoporosis candidate genes within the 3p14-25 selleck inhibitor [38] No abnormal bone-related phenotypes were reported in TDGF1-deficient mice Materials and methods Subjects This study included 1,080 southern Chinese female subjects selected from an expanding database of the Hong Kong Osteoporosis Study. Participants were ambulatory subjects recruited at road shows and health talks on osteoporosis since 1998. Women with a history of diseases known to affect bone mass including vitamin D deficiency, hypercalcaemia, primary and secondary hyperparathyroidism, hyper- and hypothyroidism, metabolic and congenital

bone diseases, and use of medications BAY 1895344 that would affect bone metabolism were excluded. A detailed description of subject ascertainment, inclusion, and exclusion criteria has been described previously [4]. BMD was measured by dual energy X-ray absorptiometry (Hologic

QDR 4500 plus, Waltham, MA, USA). The in vivo precision of the machine for lumbar spine, femoral neck, and total hip selleck region was 1.2%, 1.5%, and 1.5%, respectively. Subjects with extreme BMD Z-scores at either lumbar spine L1–4 or femoral neck were included in the current study. Subjects with BMD Z-score ≤ −1.28 (lowest tenth percentile of the population) were defined as cases, while those with BMD Z-score ≥ +1 (highest 15th percentile of the population) were defined as controls. All participants gave informed consent, and the study was approved by the Ethics Fludarabine in vivo Committee of the University of Hong Kong and conducted according to the Declaration of Helsinki. There were 457 cases and 254 controls for lumbar spine, 399 cases and 283 controls for femoral neck, and 356 cases and 260 controls for total hip. The Student’s t test was applied to compare the characteristics and phenotypes of the cases and controls. Age, height, and weight are potential confounding factors influencing BMD variation. According to our previous heritability estimates for BMD, the proportion of variation explained by age, age2, height, and weight was around 0.3 in women [4].