Familial Chylomicronemia Syndrome: A Clinical Guide for Endocrinologists

ABSTRACT

Objective: Familial chylomicronemia syndrome (FCS) is a rare autosomal recessive disorder caused by mutations in lipoprotein lipase, resulting in accumulation of chylomicrons in plasma and hypertriglyceridemia. Elevated triglycerides cause several complications in patients, the most serious being episodes of acute pancreatitis. This review focuses on expert guidance and opinion from an experienced lipidologist and endocrinologist as well as a current review of the literature, as there are no specific guidelines on FCS. Methods: Discussion of expert guidance and opinion review of current literature. Results: To date, there is no pharmacologic treatment for affected patients, and management options primarily include adoption of an extremely restricted, very-low-fat diet, along with avoidance of certain medications and alcohol. Endocrinologists often diagnose and manage patients with metabolic disorders, including patients with high triglyceride levels, but rare diseases like FCS can be missed or poorly evaluated due to knowledge gaps about disease state. Given endocrinologists' role in the treatment of lipid disorders, it is important that they understand the clinical signs and symptoms of FCS to correctly diagnose patients. Patients with FCS can be identified based on a defined clinical criteria and a thorough review of medical history, after excluding differential diagnoses and secondary factors. Typical manifestations include hypertriglyceridemia characterized by lipemic serum, history of abdominal pain, and acute/recurrent pancreatitis. Secondary factors to be excluded are pregnancy, alcohol abuse, uncontrolled diabetes, and use of certain medications. Conclusion: FCS is a rare, inherited lipid disorder disease that often goes underdiagnosed and unmanaged. This review provides a summary of clinical characteristics of FCS that can be potentially used to screen patients in an endocrinologist's office and direct them to the appropriate standard of care. Abbreviations: apoB = apolipoprotein B; apoC-III = apolipoprotein CIII; ASO = antisense oligonucleotide; FCS = familial chylomicronemia syndrome; HTG = hypertriglyceridemia; LPL = lipoprotein lipase; LPLD = lipoprotein lipase deficiency