Allelic drop-out in the LDLR gene affects mutation detection in familial hypercholesterolemia

Objectives: Familial hypercholesterolemia is a monogenic disorder caused by mutations in the LDL receptor ( LDLR ) gene. We observed allelic drop-out during LDLR genotyping and aimed at redesigning mutation detection. Design and methods: The NanoChip microelectronic array technology and PCR restriction fragment length polymorphism analysis were used. Results: Allele drop-out caused false homozygous diagnoses and was overcome using PCR primers without polymorphisms in the primer binding site. Conclusions: This report presents the importance of allele drop-out in LDLR genotyping.