Familial hypertriglyceridemia is an uncommon primary (genetic) dyslipidemia characterized by moderately elevated serum VLDL triglycerides, larger triglyceride-rich particles, and an increased triglyceride-to-apoB ratio usually in the absence of significant hypercholesterolemia (lipoprotein phenotype IV) and rarely manifests in childhood. VLDL-triglyceride turnover studies showed that the metabolic defect in patients with familial hypertriglyceridemia is triglyceride overproduction driving an increase in large triglyceride-enriched VLDLs.
Generally, hypertriglyceridemia is a heterogeneous anomaly, not only due to different underlying pathophysiological mechanisms, but also in terms of cardiovascular risk. However, in familial hypertriglyceridemia, cardiovascular risk is apparently only moderately affected.
Familial hypertriglyceridemia has been suggested to be an autosomal dominant condition with low penetrance before age 30. It is linked to mutations in APOA5 (apolipoprotein A5) gene and LIPI (lipase I) gene.