A novel BMD locus within PTCH1, which encodes protein patched homologue 1 (the receptor for three Hedgehog morphogens), is associated with reduced BMD at the spine (P = 1.0 × 10−11) and an increased risk of osteoporotic fractures (P = 8.5 × 10−4, OR = 1.09), according to a new study published in Nature Communications. The locus was identified in a genome-wide association study of individuals from Iceland with BMD measurements at the spine (n = 20,132) and the hip (n = 20,162) and a follow-up in 10,091 individuals of Northern European (Danish and Australian) and East-Asian (Korean and Hong Kong Chinese) descent. The researchers also identified a new spine BMD locus within RSPO3 (encoding R-spondin-3, an activator of the Wnt signalling pathway) associated with increased BMD at the spine (P = 6.6 × 10−10) and a decreased risk of osteoporotic fractures (P = 2.0 × 10−4, OR = 0.86).