Manhattan plot of the genome-wide analysis of erosive hand osteoarthritis The p values (−log10) are plotted against their respective positions on each chromosome. Results are shown for all variants with significance level p<0.001 and imputation information greater than 0.8.

Loss of bmp6 causes erosive-like phenotypes in the zebrafish vertebral precursors. (A–C’). Analysis of cartilage (blue) and bone (red) in the vertebral column of 14 days post fertilisation wild-type (WT) and bmp6^+/- zebrafish larvae. (A, A’) WT larvae have a normally segmented and ossified centra (vertebral precursors) and neural (na) and hemal arches (ha), whereas (B, C’) bmp6^{+/ −} have multiple defects, including bone erosions (arrow in B and B’), structural defects in the centra (arrowhead in B, C and C’), ectopic cartilage formation (arrow in C’), and disruptions in the neural and hemal arches (asterisks in C’). No defects are observed in the cartilaginous structures of the fins. All images are lateral views with anterior to the left.

Genetic correlation between EHOA and other OA subtypes and diseases/traits The genetic correlation coefficient (r_g) and SE, of genetic correlation between EHOA and other OA subtypes, any OA (which includes all types of OA), and several diseases/traits are shown. HGS is hand grip strength, FN_BMD is femoral neck bone mineral density, LS_BMD is lumbar spine bone mineral density, and RA is rheumatoid arthritis. BMD, bone mineral density; EHOA, erosive hand osteoarthritis; LS-BMD, lumbar spine BMD; OA, osteoarthritis.