INTRODUCTION: Bone mineral density has a strong genetic component but it is also influenced by environmental factors making it a complex trait to study. LRP5 gene was previously shown to be involved in rare diseases affecting bone mass. Mutations associated with gain-of-function were described as well as loss-of-function mutations. Following this discovery, many frequent LRP5 polymorphisms were tested against the variation of BMD in the normal population. MATERIALS AND METHODS: Heel bone parameters (SOS, BUA) were measured by right calcaneal QUS in 5021 healthy French-Canadian women and for 2104 women, BMD evaluated by DXA at two sites was available (femoral neck (FN) and lumbar spine (LS)). Among women with QUS measures and those with DXA measures, 26.5% and 32.8% respectively were premenopausal, 9.2% and 10.7% were perimenopausal and 64.2% and 56.5% were postmenopausal. About a third of the peri- and postmenopausal women never received hormone therapy. Two single nucleotide coding polymorphisms (Val667Met and Ala1330Val) in LRP5 gene were genotyped by allele-specific PCR. All bone measures were tested individually for associations with each polymorphism by analysis of covariance with adjustment for non genetic risk factors. Furthermore, haplotype analysis was performed to take into account the strong linkage disequilibrium between the two polymorphisms. RESULTS AND CONCLUSION: The two LRP5 polymorphisms were found to be associated with all five bone measures (L2L4 and femoral neck DXA as well as heel SOS, BUA and stiffness index) in the whole sample. Premenopausal women drove the association as expected from the proposed role of LRP5 in peak bone mass. Our results suggest that the Val667Met polymorphism is the causative variant but this remains to be functionally proven.
INTRODUCTION: Bone mineral density has a strong genetic component but it is also influenced by environmental factors making it a complex trait to study. LRP5 gene was previously shown to be involved in rare diseases affecting bone mass. Mutations associated with gain-of-function were described as well as loss-of-function mutations. Following this discovery, many frequent LRP5 polymorphisms were tested against the variation of BMD in the normal population. MATERIALS AND METHODS: Heel bone parameters (SOS, BUA) were measured by right calcaneal QUS in 5021 healthy French-Canadian women and for 2104 women, BMD evaluated by DXA at two sites was available (femoral neck (FN) and lumbar spine (LS)). Among women with QUS measures and those with DXA measures, 26.5% and 32.8% respectively were premenopausal, 9.2% and 10.7% were perimenopausal and 64.2% and 56.5% were postmenopausal. About a third of the peri- and postmenopausal women never received hormone therapy. Two single nucleotide coding polymorphisms (Val667Met and Ala1330Val) in LRP5 gene were genotyped by allele-specific PCR. All bone measures were tested individually for associations with each polymorphism by analysis of covariance with adjustment for non genetic risk factors. Furthermore, haplotype analysis was performed to take into account the strong linkage disequilibrium between the two polymorphisms. RESULTS AND CONCLUSION: The two LRP5 polymorphisms were found to be associated with all five bone measures (L2L4 and femoral neck DXA as well as heel SOS, BUA and stiffness index) in the whole sample. Premenopausal women drove the association as expected from the proposed role of LRP5 in peak bone mass. Our results suggest that the Val667Met polymorphism is the causative variant but this remains to be functionally proven.
Authors: Qing Xiong; Yan Jiao; Karen A Hasty; S Terry Canale; John M Stuart; Wesley G Beamer; Hong-Wen Deng; David Baylink; Weikuan Gu Journal: Genomics Date: 2009-01-14 Impact factor: 5.736
Authors: Fulvio Lauretani; Chiara Cepollaro; Stefania Bandinelli; Antonio Cherubini; Alessia Gozzini; Laura Masi; Alberto Falchetti; Francesca Del Monte; Silvia Carbonell-Sala; Francesca Marini; Annalisa Tanini; Anna Maria Corsi; Gian Paolo Ceda; Maria Luisa Brandi; Luigi Ferrucci Journal: Aging Clin Exp Res Date: 2010-08 Impact factor: 3.636
Authors: Joyce B J van Meurs; Thomas A Trikalinos; Stuart H Ralston; Susana Balcells; Maria Luisa Brandi; Kim Brixen; Douglas P Kiel; Bente L Langdahl; Paul Lips; Osten Ljunggren; Roman Lorenc; Barbara Obermayer-Pietsch; Claes Ohlsson; Ulrika Pettersson; David M Reid; Francois Rousseau; Serena Scollen; Wim Van Hul; Lidia Agueda; Kristina Akesson; Lidia I Benevolenskaya; Serge L Ferrari; Göran Hallmans; Albert Hofman; Lise Bjerre Husted; Marcin Kruk; Stephen Kaptoge; David Karasik; Magnus K Karlsson; Mattias Lorentzon; Laura Masi; Fiona E A McGuigan; Dan Mellström; Leif Mosekilde; Xavier Nogues; Huibert A P Pols; Jonathan Reeve; Wilfried Renner; Fernando Rivadeneira; Natasja M van Schoor; Kurt Weber; John P A Ioannidis; André G Uitterlinden Journal: JAMA Date: 2008-03-19 Impact factor: 56.272