Familial hypercholesterolemia with multiple large tendinous xanthomas and advanced coronary artery atherosclerosis.

We herein report the case of a 53-year-old man with severe coronary ischemia who underwent successful coronary artery bypass surgery. Of note, he had hypercholesterolemia and presented with multiple large tendinous xanthomas and thickened Achilles tendons that had been present for more than two decades. Together with a family history of dyslipidemia, the patient was diagnosed as having familial hypercholesterolemia. Irrespective of an extensive search for possible mutations in the genes presumably involved in the patient's pathophysiology, including low-density lipoprotein receptor (LDLR), proprotein convertase subtilisin/kexin type 9 (PCSK9), autosomal recessive hypercholesterolemia (ARH) and apolipoprotein B (APOB), we were not able to identify the gene mutations responsible for the phenotype observed in the present case.