Universal Screening for Familial Hypercholesterolemia in Preschool Children and Their Families in Slovenia (FH-FAMILIES)-A Protocol for a Study of Four-Stage Screening Program.

Familial hypercholesterolemia (FH) is the most common metabolic disease, with prevalence estimated between 1:250 and 1:300. The affected individuals have a significantly higher risk for developing atherosclerosis and cardiovascular disease (CVD) compared to non-affected individuals. Early CVD can be prevented with early detection and treatment of FH. In Slovenia we have been conducting a national three-staged program of universal screening for FH of preschoolers. Goals: Our goal is to collect data for 5000 children, which is approximately one-quarter of one generation of preschoolers for the year 2023 (n = 5000). Methods: Our study includes both prospective and retrospective components and is a non-interventional cohort study. The prospective component began in 2023, when a questionnaire was distributed to multiple community health centers and outpatient practices in Slovenia. Pediatricians or school medicine specialists completed these questionnaires. The retrospective component involves our research team collecting the remaining necessary data from existing medical records. We are going to follow our algorithm for the implementation of the universal cholesterol screening program and seek all children that will be referred to the Pediatric Lipid Clinic at the University Children's Hospital, University Medical Centre (UCH-UMC), Ljubljana, for further genetic testing. If a child has a positive genetic result, their parents and siblings will undergo genetic testing. Conclusions: Despite being a common genetic disorder, familial hypercholesterolemia (FH) is still largely underdiagnosed globally; fewer than 10% of affected individuals are thought to be identified. Early detection through effective screening is therefore essential to improve outcomes and prevent premature cardiovascular events.