The registry is maintained at the Regional Centre for Rare Diseases, established in 2016, within Polish Mother's Memorial Hospital Research Institute. This facility diagnoses and treats over 80 distinct rare diseases in patients from across the country, including those with phenotypically or genetically confirmed familial hypercholesterolemia (FH).

All consecutive patients diagnosed with FH, including both children and adults, are being enrolled from December 2018 to May 2024. Each patient receives a consultation with a clinical geneticist and a dietitian, who provide recommendations for cascade screening among family members and promote a healthy and balanced diet. The study includes all index cases, with children also serving as index cases.

The PMMHRI FH registry is managed by physicians from the RCRD, who exclusively make all diagnostic and treatment decisions. The purpose of the registry is to investigate the clinical characteristics, diagnosis, management, achievement of therapeutic goals, and outcomes of FH patients. Inclusion criteria are based on phenotypic or genetic diagnosis of FH. Phenotypic diagnosis is conducted using the Dutch Lipid Clinic Network criteria for adults, and the Simon Broome criteria for children. During the baseline visit, comprehensive data collection includes all available lipidogram results, aiming to obtain naive LDL-C values, highest values, and treated values. All data collected during the enrollment period are included in the study.

Inclusion Criteria:

• FH diagnosis

Exclusion Criteria:

-

All consecutive patients diagnosed with FH, including both children and adults,