National Lipid Association Releases Expert Clinical Review on Familial Chylomicronemia Syndrome (FCS)

The National Lipid Association (NLA) has released a comprehensive clinical review titled “Familial Chylomicronemia Syndrome: An Expert Clinical Review from the National Lipid Association.” This new guidance provides an in-depth examination of the diagnosis, management, and treatment landscape for familial chylomicronemia syndrome (FCS) — a rare and severe genetic disorder characterized by extremely high triglyceride levels (≥ 1,000 mg/dL) and an elevated risk of life-threatening recurrent acute pancreatitis.

“This comprehensive statement synthesizes critical knowledge on FCS, a severe genetic disorder causing extremely high triglycerides and a life-threatening risk of recurrent acute pancreatitis,” said Zahid Ahmad, MD, FNLA, lead author and lipidologist. “The expert opinion highlights the challenges of diagnosis, the necessity of a lifelong ultra-low-fat diet (< 15% of energy), and the promise of new therapies targeting apolipoprotein C-III (APOC3) like olezarsen (recently FDA-approved) and plozasiran (under FDA review), which offer hope for reducing triglycerides and pancreatitis risk in FCS patients.”

The expert review outlines key clinical guidance across a broad spectrum of topics, including:

• Diagnosis of FCS – Recognizing hallmark clinical and laboratory features to distinguish FCS from more common multifactorial chylomicronemia syndrome (MCS).
• Differentiation of FCS vs. MCS – Highlighting the genetic basis of FCS and the importance of excluding secondary causes of hypertriglyceridemia.
• Complications – Addressing the risk of acute pancreatitis, hepatic steatosis, and psychosocial burdens faced by FCS patients.
• Primary and Pharmacologic Management – Reinforcing the role of a strict lifelong ultra-low-fat diet and discussing current and emerging medications, including APOC3-targeted therapies.
• Special Populations – Providing clinical considerations for pediatric patients, pregnancy monitoring, and the management of acute pancreatitis episodes.

FCS affects approximately 1 to 10 individuals per million and is typically caused by bi-allelic pathogenic variants affecting the clearance of triglyceride-rich lipoproteins. Due to its rarity and overlapping features with more common lipid disorders, FCS is frequently underdiagnosed or misdiagnosed, often leading to delayed care and preventable complications.

The NLA's expert review aims to bridge knowledge gaps among clinicians, improve patient outcomes, and provide a forward-looking view of the evolving treatment landscape for this devastating disorder.