Linkage exclusion mapping with bone size in 79 Caucasian pedigrees

Bone size is an important risk factor of osteoporotic fractures and has strong genetic determination. However, genetic studies on bone size variation are relatively rare. In the present study, we conducted a linkage exclusion mapping for bone size variation on chromosomes 1, 4, 6, and 17 in 79 Caucasian pedigrees. For hip bone size variation, several genomic regions were excluded at effect sizes of 10% or greater, including regions of 61–77cM at 1p35-p34, 43–59cM at 4p15-p13, 1–59cM at 6p25-p21, 82–88cM at 17q23-q24, and 113–114cM at 17q25. For spine bone size, at effect sizes of 10% or greater, we excluded regions of 115–122cM at 1p31-p22, 136–141cM at 1p21, 207–260cM at 1q31-q42, 20–89cM at 4p16-q21, 11–21cM at 6p24-p23, and 1–6cM at 17p13. These results suggested that a number of candidate genes located in the excluded regions, such as the growth hormone (GH) gene, tumor necrosis factor-alpha (TNF-α) gene, and bone morphogenetic protein-3 (BMP3) gene, are unlikely to have a substantial effect on bone size variation in this Caucasian population.