The evaluation of cascade testing for familial hypercholesterolemia

Area of Science:

• Genetics
• Cardiology
• Public Health

Background:

• Familial hypercholesterolemia (FH) is an autosomal dominant disorder.
• FH significantly increases the risk of early-onset coronary heart disease.
• Cholesterol-lowering drugs can mitigate this risk.

Purpose of the Study:

• To estimate the screening performance of three cascade testing strategies for FH.
• To determine the necessary identification rates of unrelated FH index cases for effective screening.
• To evaluate the suitability of cascade testing for population-level FH screening.

Main Methods:

• Computer simulation was employed to model cascade testing strategies.
• Three strategies were evaluated: 1st-degree relatives only, extended 1st-degree relatives, and inclusion of 2nd/3rd-degree relatives.
• The study calculated required detection rates for index cases and overall FH individuals.

Main Results:

• Achieving 80% detection rates via cascade testing requires identifying 25% (strategy i), 11% (strategy ii), or 8% (strategy iii) of unrelated FH index cases.
• To achieve these rates, 45% (i), 23% (ii), or 17% (iii) of all FH individuals must be identified independently.
• Cascade testing alone is insufficient for population screening due to low detection rates.

Conclusions:

• Cascade testing is not a suitable standalone method for population screening of Familial Hypercholesterolemia.
• A separate, systematic method for identifying new FH index cases is essential for effective population screening.
• Such an alternative systematic method could serve as the primary population screening strategy for FH.