Welcome to the Rare Classroom, a new series from Patient Worthy. Rare Classroom is designed for the curious reader who wants to get informed on some of the rarest, most mysterious diseases and conditions. There are thousands of rare diseases out there, but only a very small number of them have viable treatments and regularly make the news. This series is an opportunity to learn the basics about some of the diseases that almost no one hears much about or that we otherwise haven’t been able to report on very often.

Eyes front and ears open. Class is now in session.

The disease that we will be learning about today is:

Familial Chylomicronemia Syndrome

Also known as familial lipoprotein lipase deficiency.

What is Familial Chylomicronemia Syndrome?

• FCS is characterized by the build up of chylomicrons (chylomicronemia), the largest of the lipoprotein particles, which are responsible for transporting dietary fat and cholesterol. The inability to breakdown chylomicrons leads to a build up of triglycerides in the blood​
• Approximately 1 in 500 heterozygous individuals are carriers of Familial Chylomicronemia Syndrome (FCS), while an approximate 1 in 1 million homozygous individuals are diagnosed​
• FCS is characterized by the lack of the ability the lipoprotein lipase enzymes needed to breakdown
• Treatment and other economic costs due to Familial Chylomicronemia Syndrome (FCS) can vary greatly due to the severity of the disease with estimations of annual costs being roughly $8,029 for patients without a history of acute pancreatitis and $33,587 for those with a history of acute pancreatitis​

How Do You Get It?

• FCS can be passed on from a parent to a child by way of a recessive, genetic defect or mutation that affects the function and regulation of the LPL enzyme​
• If both parents are heterozygous carriers, the risk of FCS in their child is 25%
• Certain populations in Quebec and the Netherlands are genetically more likely to have FCS​
• No evidence to suggest that one sex is more prone to FCS than the other
• Most commonly diagnosed early in an individual’s life as symptoms arise (about 25%), but some individuals may not be diagnosed until their 20s

What Are The Symptoms?

• Patients often present with several severe symptoms before FCS is diagnosed. Many experience pancreatitis, an acute recurrent inflammation of the pancreas, which causes debilitating pain and can be fatal. An accurate diagnosis is critical to initiating customized, life-long management specific to FCS for the individual affected​
• Those living with FCS can be at risk for severe recurrent abdominal pain and potentially fatal pancreatitis, as well as symptoms that can interfere with daily living, including fatigue, lack of energy (asthenia), impaired cognition, and numbness/tingling, so finding a treatment for this disease is crucial​
• Vomiting/Diarrhea
• Neurological impairment
• Lipemia retinalis
• Hepato/Splenomegaly​
• Xanthomas​
• Foam Cell Infiltration of Bone Marrow​

How Is It Treated?

• The goal of treatment is to reduce and regulate the triglyceride levels in the body​
• Currently there are no FDA-approved treatments, although many patients utilize a strict low-fat diet to combat the effects of FCS​
• The major barrier to examining this disease state is its rarity and difficulty to diagnose. This has delayed the development of treatments as more research is needed on the disease. ​
• An FCS patient’s healthcare team will include their GP, and endocrinologist given this disease affects the pancreas, dietician to help regulate fat levels in their diet, and possibly a therapist to help with the psychosocial concerns of FCS​
• IV/Sub-Q Injections​
  • This therapy works by introducing glycoproteins into the liver that plays a key role in regulating triglycerides​
• Oral Medications
  • These medications are approved outside the United States ​
    
  • These function in various different ways based on their usage, being a primary treatment or a supplementary treatment to better help the efficacy of other treatments, such as dieting​
• Diet
  • A diet consisting of extremely low fats (less that 10-15g a day), low simple carbohydrates, and being alcohol-free is deemed to be the current standard of care for FCS​
    
  • This diet will have to be a life-long commitment for FCS, and with the help of a dietician, patients can obtain medium chain triglyceride oil, which a source of fat and calories that is safe for FCS patients to eat​

Where Can I Learn More???

• Check out our cornerstone on this disease here.
• Learn more about this disease from the FCS Foundation.