Objective To identify LDLR gene mutation in patients with familial hypercholesterolemia(FHC)combined with hyperthyroidism(HD). Methods Peripheral blood of the family constellation was collected for DNA extraction.Employing TOUCH-DOWN PCR amplification was done in LDLR gene promoters and total 18 exon fragments of the patients and their six family members,a sequencing analysis was then carried out.In addition,mutations of Q3500 R,R3531and R3500 Wof apolipoprotein B100 gene were detected to exclude familial d...