BBS1 and cardiovascular disorder: This study indicates that patients with missense mutations in BBS1 may be at lower risk of cardiovascular disease than patients with homozygous truncating mutations and mutations in BBS10. In practice most patients with BBS10 mutations harbour the common homozygous truncating mutation and it is possible that the resulting truncated protein product or a hypomorphic effect of the common missense mutation M390R in BBS1, rather than the affected gene, determines the phenotypic effect.