Multiple Cutaneous Xanthomas Revealing Severe Familial Hypercholesterolemia in a Child: A Case Report

Abstract

Familial hypercholesterolemia (FH) is an inherited disorder characterized by markedly elevated low-density lipoprotein cholesterol (LDL-C) from childhood and an increased risk of premature atherosclerotic cardiovascular disease. We report a 12-year-old boy with multiple cutaneous and tendinous xanthomas, bilateral xanthelasma, and corneal arcus, with an LDL-C level of 600 mg/dL (15.5 mmol/L). Secondary causes of hypercholesterolemia were excluded. A limited molecular analysis targeting exon 6 of LDLR did not identify a pathogenic variant, while comprehensive genetic testing was unavailable; therefore, the diagnosis remained phenotypic rather than molecularly confirmed. Stepwise atorvastatin titration up to 20 mg/day followed by ezetimibe 10 mg/day reduced LDL-C to 400 mg/dL (10.3 mmol/L), but substantial hypercholesterolemia persisted. This case illustrates the diagnostic and therapeutic challenges of severe pediatric FH when comprehensive genetic testing and advanced lipid-lowering therapies are not readily accessible.