Genetic deficiency of albumin raises LDL cholesterol almost as much as familial hypercholesterolemia (FH) variants do. Yet ALB is not recognized as a cause of FH. In ~560k individuals from Geisinger and All of Us, 77 (1 in 7,289) carried an ALB loss-of-function variant. Their albumin was 0.69 g/dL lower and their LDL-C 38 mg/dL higher than in people without an ALB or FH variant. ALB pLoF carriers are rarer than LDLR and APOB carriers, but commoner than PCSK9 gain-of-function carriers. The effect sizes follow the same order. Here is the interesting part. A polygenic score for blood albumin levels says the lower the genetically predicted albumin, the lower the LDL cholesterol. The inverse of what the rare variants tell us. This is likely because the polygenic score is dominated by trans variants that capture overall liver health (liver output, inflammation) rather than albumin itself. A score built only from variants within the ALB gene agrees with the rare variant findings. Berry et al. JACC 2026