Familial Hypercholesterolemia

Global Prevalence:

• The World Health Organization (WHO) estimates that FH affects about 1 in every 200 to 250 people worldwide.
• According to the European Atherosclerosis Society, the prevalence of heterozygous FH (the most common form) is approximately 1 in 200 to 1 in 250 individuals in most populations.
• Homozygous FH, which is a more severe form, is rarer, with an estimated prevalence of around 1 in 160,000 to 1 in 300,000 individuals globally.

Prevalence in India:

• Studies in India have reported varying prevalence rates. Some estimates suggest FH affects about 1 in 250 individuals, while others indicate it could be as low as 1 in 500.
• Due to the large population size of India, even a prevalence of 1 in 500 would mean a significant number of people affected by this condition.

Factors Influencing Prevalence:

• FH prevalence can vary based on genetic factors, ethnicities, and lifestyles.
• Regions with higher rates of conditions related to FH (like premature coronary artery disease) often have a higher prevalence of FH.
• Awareness and diagnosis rates also impact reported prevalence. In some areas, FH may be underdiagnosed or misdiagnosed, leading to lower reported prevalence rates.

Genetic testing plays a crucial role in the diagnosis and management of familial hypercholesterolemia. Here are some of its uses:

• Diagnosis: Genetic testing can confirm a clinical diagnosis of FH. This is particularly important because symptoms alone may not be sufficient for a diagnosis, especially in cases where symptoms are mild or absent. Identifying the specific genetic mutation causing FH can also help in diagnosing other family members.
• Risk Assessment: Genetic testing can identify family members who have inherited the FH-causing mutation. This allows for early screening and intervention, reducing the risk of cardiovascular disease.
• Treatment Guidance: Different mutations can have varying effects on the severity of FH and response to treatment. Genetic testing can help tailor treatment plans. For example:
  • Some individuals may require more aggressive cholesterol-lowering therapies.
  • Knowing the genetic mutation can also guide the use of specific medications, such as PCSK9 inhibitors, which can be highly effective in FH patients.
  • Lifestyle modifications can also be more targeted based on genetic information.
• Cascade Screening: Once a familial mutation is identified, other family members can undergo genetic testing to determine if they have also inherited the mutation. This cascade screening can identify individuals at risk and allow for early intervention.
• Reproductive Planning: Individuals with FH who are planning to have children may opt for genetic testing to understand the risk of passing the condition to their offspring. This information can guide decisions about family planning and prenatal testing.
• Research and Clinical Trials: Genetic testing contributes to research on FH by identifying new mutations and understanding how they impact cholesterol metabolism. This information is valuable for developing new treatments and participating in clinical trials.

Familial hypercholesterolemia–epidemiology, diagnosis, and screening.