What is Rare Disease?

A disease is rare when it affects fewer than 1 in 2000 people. While each rare disease impacts fewer people individually, collectively, rare diseases affect over 300 million people worldwide. They are often chronic, progressive, and life-threatening, presenting unique challenges for patients, caregivers, and healthcare systems.

Rare Disease Day, observed annually on the last day of February, is a global initiative to raise awareness and advocate for the rights of individuals and families living with rare diseases. Rare Disease Day was created in 2008 by EURORDIS, the European Organisation for Rare Diseases and is coordinated by EURORDIS and its 65+ national alliance patient organisation partners.  This day unites patients, healthcare professionals, researchers, and organisations to amplify their voices and drive change.

At FH Europe Foundation, Rare Disease Day is an important date in our calendar, providing an opportunity to raise awareness for Homozygous Familial Hypercholesterolaemia (HoFH) and Familial Chylomicronaemia Syndrome (FCS)

Rare Disease Day, observed annually on the last day of February, is a global initiative to raise awareness and advocate for the rights of individuals and families living with rare diseases. Rare Disease Day was created in 2008 by EURORDIS, the European Organisation for Rare Diseases and is coordinated by EURORDIS and its 65+ national alliance patient organisation partners.  This day unites patients, healthcare professionals, researchers, and organisations to amplify their voices and drive change.

HoFH (Homozygous Familial Hypercholesterolaemia) is a rare and severe form of FH, affecting approximately 1 in 300,000 people worldwide. It occurs when a child inherits two altered FH-causing genes, one from each parent. Individuals with HoFH typically have extremely high untreated LDL cholesterol levels, ranging from 400 to 1000 mg/dL (4 to 10 times the normal level). Without diagnosis and treatment, HoFH can lead to early-onset cardiovascular complications, including heart disease and aortic valve disease, sometimes appearing in childhood.

FCS (Familial Chylomicronaemia Syndrome) is a rare genetic disorder caused by the inability to properly metabolise dietary fat due to defective or absent lipoprotein lipase (LPL) or related components. This leads to high levels of chylomicrons and triglycerides in the blood, resulting in symptoms that vary in severity based on these levels.

FCS is an autosomal recessive condition, requiring two altered genes—one from each parent. Most cases are due to mutations in genes coding for LPL or apolipoprotein C-II, a cofactor necessary for LPL function. Symptoms typically appear in childhood or adolescence but may arise later depending on the genetic mutation.

Together, we can ensure that no one living with a rare disease is left behind. Join us in celebrating the strength, courage, and stories of those who inspire us every day.