A case report of an Egyptian family with familial hypercholesterolemia and an exonic LINE‐1 insertion in LDLR

Abstract Background Familial hypercholesterolemia (MIM: PS143890) is a genetic disorder characterized by an increase in blood cholesterol. LDLR is one of the genes which their defect contributes to the disorder. Affected individuals may carry a heterozygous variant or homozygous/compound heterozygous variants and those with biallelic pathogenic variants present more severe symptoms. Method We report an Egyptian family with familial hypercholesterolemia. Both the proband and parents have the disorder while a sibling is unaffected. Exome sequencing was performed to identify the causal variant. Results LINE‐1 insertion in exon 7 of LDLR was identified. Both parents have a heterozygous variant while the proband has a homozygous variant. The unaffected sibling did not carry the variant. Discussion This insertion may contribute to the high prevalence of hypercholesterolemia in Egypt and the finding underscores the importance of implementing mobile element insertion caller in routine bioinformatics pipeline.