IMPE Abstracts

Familial hyperchylomicronemia is an autosomal recessive disorder, most often caused by mutation of the LPL gene, located on chromosome 8p22. It is characterized by severe hypertriglyceridemia secondary to chylomicron accumulation: in the absence of lipoprotein lipase (LPL) the hydrolysis of triglycerides is reduced as well as and their release into cells. It is a rare condition with an estimated incidence of 1:500,000 to 1:1,000,000 cases.

Case report: L.S.S.F.O, female, 3 months old. Admitted to the pediatric emergency department for investigation of irritability and sudden nodulation in the right axillary region. She had previous laboratory data with abnormal levels of triglycerides and total cholesterol and history of milky blood in previous venous punction. Lipid profile was requested with difficult dosage, due to sample characteristics. In a boold dilution performed at that moment, an important increase in triglycerides was observed, associated with a reduction in HDL and an increase in LDL cholesterol (Total Cholesterol: 1,377mg/dl, HDL Cholesterol: 16mg/dl, LDL Cholesterol: 513mg/dl, triglycerides: 19,778mg/dl). Patient had no clinical evolution to pancreatitis at that moment, and a strong hypothesis of familial hyperchylomicronemia was made. Initial management was performed with a specific diet: skimmed milk, medium-chain triglycerides and oats, in addition to breastfeeding avoidance. She is currently receivind a diet restricted in fat (less than 10% of the total caloric recommendation), polyunsaturated fatty acids, vitamin D supplementation (fat-soluble) and omega 3 fatty acids. So far, she hasn’t had any acute complications secondary to the condition, and her triglycerides range between 600 -1000mg/dl. A genetic panel for hypertriglyceridemia and pancreatitis was performed and a lipoprotein lipase deficiency was found [identifiend in homozigozity in the LPL gene, the variant Chr8:19,954,222 G>A, which promotes the replacement of the amino acid glycine at codon 215 by glutamate (p.Gly215Glu)].

Discussion: Treatments proposed for the condition are a calorie-restricted diet, weight reduction, and in some cases, common lipid-lowering drugs, such as fibrates or omega-3 fatty acids. Volanesorsen, an antisense oligonucleotide against apolipoprotein C-III, is the only drug approved to control the disease to date, but its use is limited to adult patients. Thus, multidisciplinary follow-up is essential for pediatric patients, for adequate dietary management, thus avoiding possible complications (xanthomas, hepatosplenomegaly, pancreatitis).