COL1A1 and osteoporosis: First, we recapitulate many known associations from previous studies, including associations between PCSK9 and LDL cholesterol (pLoF burden p = 3.5 × 10−132), COL1A1 and bone density (pLoF burden p = 2 × 10−9),26KLF1 and several red blood cell traits (pLoF burden < 2 × 10−12),27 and LRP5 (Wnt coreceptor) and bone density and osteoporosis phenotypes (pLoF burden < 5 × 10−7).28