Several genomic regions potentially containing QTLs for bone size variation were identified in a whole‐genome linkage scan

Bone size is an important determinant of osteoporotic fractures. For a sample of 53 pedigrees that contains more than 10,000 relative pairs informative for linkage analyses, we performed a whole‐genome linkage scan using 380 microsatellite markers to identify genomic regions that may contain QTLs of bone size (two dimensional measurement by dual energy X‐ray absorptiometry). We conducted two‐ and multi‐point linkage analyses. Several potentially important genomic regions were identified. For example, the genomic region 17q23 may contain a QTL for wrist (ultra distal) bone size variation; a LOD score of 3.98 is achieved at D17S787 in two‐point analyses and a maximum LOD score (MLS) of 3.01 is achieved in multi‐point analyses in 17q23. 19p13 may contain a QTL for hip bone size variation; a LOD score of 1.99 is achieved at D19S226 in two‐point analyses and a MLS of 2.83 is achieved in 19p13 in multi‐point analyses. The genomic region identified on chromosome 17 for wrist bone size seems to be consistent with that identified for femur head width variation in an earlier whole‐genome scan study. The genomic regions identified in this study and an earlier investigation on one‐dimensional bone size measurement by radiography are compared. The two studies may form a basis for further exploration with larger samples and/or denser markers for confirmation and fine mapping studies to eventually identify major functional genes and the associated etiology for osteoporosis. © 2003 Wiley‐Liss, Inc.