Algorithm for familial hypercholesterolemia (FH) testing in children based on findings in first-degree relatives

FH is typically due to pathogenic variants in one of three genes, LDLR, APOB, or PCSK9. Pathogenic variants in other genes such as APOE or LDLRAP1 may rarely be responsible. The age of testing depends on the likelihood that FH is homozygous (biallelic pathogenic variants in one of these genes) or heterozygous (a pathogenic variant on one allele). Decisions about genetic testing in children are made with shared decision-making with the parents or other caregivers and take into account concerns about disease risk and genetic discrimination. Routine lipid screening in children is generally not considered accurate before 2 years of age; however, lipid testing can be performed at any age if there are other reasons for concern, such as a positive family history, physical examination findings, or positive results from genetic testing. Results of genetic testing are not affected by age or medications. Refer to UpToDate for further information and additional algorithms that address cardiovascular risk assessment, lipid screening, and management of lipid disorders.