The Effect of a Fat-Restricted Diet in Four Patients with Familial Chylomicronemia Syndrome: A Long-Term Follow-Up Study

(1) Background: Familial chylomicronemia syndrome (FCS) is a very rare autosomal recessive disorder characterized by severely elevated triglycerides and clinical symptoms in early childhood mainly presenting with abdominal pain, acute pancreatitis and hepatosplenomegaly. Primary treatment is a lifelong very strict low-fat diet, which might be challenging in pediatric patients. So far, data about children with FCS are rare. The aim of this study was to show the familial chylomicronemia syndrome traffic light table for pediatric patients and to assess the dietary fat intake and impact on triglycerides in children with FCS. (2) Methods: We performed a retrospective analysis in four children (50% male) affected by FCS from the Department of Pediatrics and Adolescent Medicine, Medical University of Vienna between January 2002 and September 2020. (3) Results: The four patients presented with classical FCS symptoms and showed baseline triglycerides (TG) exceeding 30,000 mg/dL in two patients, 10,000 mg/dL and 2400 mg/dL in one patient each. After diagnosis, fat percentage of total daily caloric intake was decreased and resulted immediately in triglyceride reduction. In all patients, FCS was genetically confirmed by mutations in genes encoding lipoprotein lipase. Acute pancreatitis and hepatosplenomegaly disappeared under the fat-restricted diet. A FCS traffic light table was developed as a dietary tool for affected families. (4) Conclusions: A restriction of dietary fat between 10% to 26% of the total daily caloric intake was feasible and effective in the long-term treatment of genetically confirmed FCS in children and could reduce the risk for acute pancreatitis. The dietary tool, the pediatric FCS traffic light table and the age-appropriate portion sizes for patients between 1 to 18 years, supports children and their parents to achieve and adhere to the lifelong strict low-fat diet