Extreme hypertriglyceridemia: Genetic diversity, pancreatitis, pregnancy, and prevalence.

Journal: Journal Of Clinical Lipidology
Published:
Abstract

Background: Triglyceride (TG) concentrations >2000 mg/dL are extremely elevated and increase the risk of pancreatitis.

Objectives: We characterized five cases and two kindreds and ascertained prevalence in a reference laboratory population.

Methods: Plasma lipids and DNA sequences of LPL, GPIHBP1, APOA5, APOC2, and LMF1 were determined in cases and two kindreds. Hypertriglyceridemia prevalence was assessed in 440,240 subjects.

Results: Case 1 (female, age 28 years) had TG concentrations >2000 mg/dL and pancreatitis since infancy. She responded to diet and medium-chain triglycerides, but not medications. During two pregnancies, she required plasma exchange for TG control. She was a compound heterozygote for a p.G236Gfs*15 deletion and a p.G215E missense mutation at LPL, as was one sister with hypertriglyceridemia and pancreatitis during pregnancy. Her father was heterozygous for the deletion and had hypertriglyceridemia and recurrent pancreatitis. Other family members had either the missense mutation or the deletion, and had hypertriglyceridemia but no pancreatitis. In kindred 2, three preschool children had severe hypertriglyceridemia and were homozygous for a GPIHBP1 p.T108R missense mutation. Case 5 (male, age 43 years) presented with pancreatitis and TG levels >5000 mg/dL and had heterozygous GPIHBP1 p.G175R and APOC2 intron 2-4G>C mutations. On diet, fenofibrate, fish oil, and atorvastatin, his TG concentration was 2526 mg/dL, but normalized to <100 mg/dL with added pioglitazone. In our population study, 60 subjects (0.014%) of 440,240 had TG concentrations >2000 mg/dL, and 66.7% were diabetic and had elevated insulin levels.

Conclusions: Extreme hypertriglyceridemia is rare (0.014%); and during pregnancy, it may require plasma exchange.

Authors
Vadzim Chyzhyk, Sarah Kozmic, Alan Brown, Lisa Hudgins, Thomas Starc, Ashley Davila, Thomas Blevins, Margaret Diffenderfer, Lihong He, Andrew Geller, Caitlin Rush, Robert Hegele, Ernst Schaefer