Table 3.

Common hypercholesterolemia and hypertriglyceridemia

	Molecular mechanism	Clinical features
Dominant inheritance
Familial hypercholesterolemia	LDLr defect	TX, arcus cornealis, premature CHD, TC: >400 mg/dL (>10.3 mmol/L) or TC: 190–400 mg/dL (4.9–10.3 mmol/L) in heFH
Familial defective APOB-100	APOB defect	Xanthomas, arcus cornealis, premature CHD, and TC: 250–350 mg/dL (7–13 mmol/L)
Familial hypercholesterolemia type 3	PCSK9	Premature CHD TC: 250–500 mg/dL (6.5–9 mmol/L)
Familial hypertriglyceridemia	Possible multiple unknown defects	No symptoms TG: 200–500 mg/dL (2.3–5.7 mmol/L)
Familial combined hyperlipidemia	Possible multiple unknown defects	Premature CHD, Apo B elevated, TC: 250–500 mg/dL (6.5–13 mmol/L) TG: 250–750 mg/dL (2.8–8.5 mmol/L)
Recessive inheritance
Autosomal recessive hypercholesterolemia	ARH	Xanthomas, arcus cornealis, xanthelasmas, premature CHD. TC: >350 mg/dL (>9 mmol/L)
LPL deficiency	Endothelial LPL defect	Failure to thrive, xanthomas, hepatosplenomegaly, pancreatitis TG: >750 mg/dL (8.5 mmol/L)
Apo C-II deficiency	Apo C-II defect	Pancreatitis and metabolic syndrome. TG: >750 mg/dL (8.5 mmol/L)
Hepatic lipase deficiency	Hepatic lipase	Premature CHD TC: 250–1,500 mg/dL TG: 395–8,200 mg/dL
Cerebrotendinous xanthomatosis	Hepatic mitochondrial 27-hydroxylase defect	Cataracts, premature CHD, neuropathy, ataxia
Sitosterolemia	ABCG5/G8	Tendon xanthomas, premature CHD
Variable inheritance
Familial dysbetalipoproteinemia	APOE (usually e2/e2 homozygotes)	Palmar xanthomas, yellow palmar creases, premature CHD. TC: 250–500 mg/dL (6.5–13 mmol/L) TG: 250–500 mg/dL (2.8–5.6 mmol/L)
Polygenic hypercholesterolemia	Possibly multiple unknown defects	Premature CHD TC: 250–350 mg/dL (6.5–9 mmol/L)

Abbreviations: CHD, coronary heart disease; LDLr, low-density lipoprotein receptor protein; LPL, lipoprotein lipase; TC, total cholesterol; TG, triglycerides; TX, tendon xanthomas.