How should I approach the initial screening and genetic testing for patients suspected of having familial hypercholesterolaemia?

For initial screening of patients suspected of having familial hypercholesterolaemia (FH), healthcare professionals should consider adults with a total cholesterol level greater than 7.5 mmol/l or a personal or family history of premature coronary heart disease (before age 60 in an index individual or first-degree relative) ¹.

Systematic search of primary care records should be performed for individuals younger than 30 years with a total cholesterol greater than 7.5 mmol/l, and for those 30 years or older with a total cholesterol greater than 9.0 mmol/l, as these are high-risk groups ¹.

Before considering a diagnosis of FH, secondary causes of hypercholesterolaemia should be excluded, such as hypothyroidism, liver disease, nephrotic syndrome, and lifestyle factors ¹.

Use clinical criteria such as the Simon Broome or Dutch Lipid Clinic Network (DLCN) criteria to make a clinical diagnosis of FH in primary care, which should be performed by a healthcare professional competent in using these criteria ¹.

If the patient meets the criteria for possible or definite FH (e.g., DLCN score >5 or meeting Simon Broome criteria), they should be referred to an FH specialist service for DNA testing ¹.

To confirm the diagnosis, healthcare professionals should undertake two measurements of LDL-C because biological and analytical variability occurs ¹.

Genetic testing, primarily DNA analysis for disease-causing mutations, is recommended following clinical suspicion and referral, especially in those meeting diagnostic criteria ¹.