title: Linkage of osteoporosis to chromosome 20p12 and association to BMP2.
abstract: Osteoporotic fractures are a major cause of morbidity and mortality in ageing populations. Osteoporosis, defined as low bone mineral density (BMD) and associated fractures, have significant genetic components that are largely unknown. Linkage analysis in a large number of extended osteoporosis families in Iceland, using a phenotype that combines osteoporotic fractures and BMD measurements, showed linkage to Chromosome 20p12.3 (multipoint allele-sharing LOD, 5.10; p value, 6.3 x 10(-7)), results that are statistically significant after adjusting for the number of phenotypes tested and the genome-wide search. A follow-up association analysis using closely spaced polymorphic markers was performed. Three variants in the bone morphogenetic protein 2 (BMP2) gene, a missense polymorphism and two anonymous single nucleotide polymorphism haplotypes, were determined to be associated with osteoporosis in the Icelandic patients. The association is seen with many definitions of an osteoporotic phenotype, including osteoporotic fractures as well as low BMD, both before and after menopause. A replication study with a Danish cohort of postmenopausal women was conducted to confirm the contribution of the three identified variants. In conclusion, we find that a region on the short arm of Chromosome 20 contains a gene or genes that appear to be a major risk factor for osteoporosis and osteoporotic fractures, and our evidence supports the view that BMP2 is at least one of these genes.
authors.affiliation: deCODE Genetics, Reykjavik, Iceland. unnur.styrkarsdottir@decode.is
authors.forename: Unnur
authors.initials: U
authors.lastname: Styrkarsdottir
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Cazier
authors.forename: Augustine
authors.initials: A
authors.lastname: Kong
authors.forename: Ottar
authors.initials: O
authors.lastname: Rolfsson
authors.forename: Helene
authors.initials: H
authors.lastname: Larsen
authors.forename: Emma
authors.initials: E
authors.lastname: Bjarnadottir
authors.forename: Vala D
authors.initials: VD
authors.lastname: Johannsdottir
authors.forename: Margret S
authors.initials: MS
authors.lastname: Sigurdardottir
authors.forename: Yu
authors.initials: Y
authors.lastname: Bagger
authors.forename: Claus
authors.initials: C
authors.lastname: Christiansen
authors.forename: Inga
authors.initials: I
authors.lastname: Reynisdottir
authors.forename: Struan F A
authors.initials: SF
authors.lastname: Grant
authors.forename: Kristjan
authors.initials: K
authors.lastname: Jonasson
authors.forename: Michael L
authors.initials: ML
authors.lastname: Frigge
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Gulcher
authors.forename: Gunnar
authors.initials: G
authors.lastname: Sigurdsson
authors.forename: Kari
authors.initials: K
authors.lastname: Stefansson
mesh_terms: D000483:Alleles; D015519:Bone Density; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000235:genetics* / Q000502:physiology*; D002874:Chromosome Mapping; D002890:Chromosomes, Human, Pair 20; D015331:Cohort Studies; D008040:Genetic Linkage; D014644:Genetic Variation; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D007055:Iceland; D015810:Linkage Disequilibrium; D008126:Lod Score; D008969:Molecular Sequence Data; D020125:Mutation, Missense; D010024:Osteoporosis / Q000235:genetics*; D010641:Phenotype; D011110:Polymorphism, Genetic; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors; D016212:Transforming Growth Factor beta / Q000235:genetics* / Q000502:physiology*
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D016212:Transforming Growth Factor beta