Familial Chylomicronaemia Syndrome (FCS)

Familial Chylomicronaemia Syndrome (FCS) is an ultra-rare disease which causes extremely high levels of triglycerides in the blood, which are a type of fat that come from food. 

What is Familial Chylomicronemia Syndrome (FCS)?

Familial Chylomicronaemia Syndrome (FCS) is an ultra-rare genetic condition that stops the body from breaking down fats consumed through food.¹ These fats are called triglycerides. People with FCS are missing the enzyme lipoprotein lipase which clears triglycerides from the blood after eating.² These fats are carried in the blood by large structures called chylomicrons and they help move triglycerides around the body where they are needed for energy and fat storage.³ 

People with FCS have a range of symptoms, and the long-term effects are usually pancreatitis and diabetes.⁴FCS is also known as familial hyperchylomicronaemia syndrome,⁵ lipoprotein lipase deficiency (LPLD), Fredrickson Type 1 hyperlipoproteinemia, or familial hypertriglyceridemia.⁶

How common is FCS?

*Living with FCS can affect a person’s quality of life and many of the symptoms of FCS cause psychosocial and clinical stress for those living with FCS and their families.⁹ The most common complication of FCS is acute and regular pancreatitis and hospitalisation. Acute severe pancreatitis can cause multi-organ failure and increases morbidity and mortality.¹⁰  

What are the symptoms of Familial Chylomicronemia Syndrome (FCS)? 

People with FCS often have daily symptoms including abdominal pain, general fatigue, and impaired condition. 

Common symptoms include:

• Frequent episodes of acute pancreatitis
• Recurrent bouts of abdominal pain
• Fatty deposits in the skin (eruptive xanthomas)
• Enlarged liver and spleen due to fat buildup
• Very high levels of a type of fat called triglyceride in the blood
• Absence of secondary causes for elevated triglycerides
• Early-onset of symptoms (childhood, adolescence, or early adulthood) ^12,13,14

These symptoms can have major emotional and psychosocial effects including anxiety, social withdrawal, depression, and brain fog.¹⁵ The long-term effects are usually pancreatitis and diabetes.¹⁶

How is FCS diagnosed?

To diagnose FCS, medical practitioners will assess clinical signs and symptoms and use diagnostic testing to identify extreme elevations in triglyceride levels.^17,18

What treatments are available for FCS?

Unfortunately, FCS cannot be cured but people living with the condition have a good life expectancy and can live into adulthood if a very low-fat diet is followed.¹⁹