Heterozygous familial hypercholesterolemia presenting as chylomicronemia syndrome.

Heterozygous familial hypercholesterolemia (HeFH) is characterized by a twofold elevation in low-density lipoprotein cholesterol. Severe elevations in triglycerides are an uncommon manifestation. In this case report, we discuss an atypical presentation of the chylomicronemia syndrome in a patient with HeFH. Genetic analyses of the low-density lipoprotein receptor mutation and single nucleotide polymorphisms that elevate triglycerides provide confirmation for this atypical presentation of HeFH.