Homozygous FH: Severely elevated cholesterol levels (total cholesterol and LDLc levels >600 mg/dL); triglyceride levels within the reference range
Heterozygous FH: Elevated LDLc levels commonly greater than 250 mg/dL; in patients younger than 20 years, an LDLc level higher than 200 mg/dL is highly suggestive of heterozygous FH or, possibly, familial ligand defective apoB-100; in adults, LDLc levels higher than 290-300 mg/dL suggest heterozygous FH