ABSTRACT
Objective To explore the molecular basis of familial hypercholesteraemia(FH)by analyzing the phenotype and genotype relationship through identify the low density liporotein receptor(LDL-r)gene mutation in a FH kindred.Methods A male patient of 15 years old was selected to examine the electrocardiogram,lipid.Color Doppler was used to examine heart and great vessels.The promoter region and the 18 exons of the LDL-r gene were screened by touch-down polymerase chain reaction(PCR)and DNA sequencing.Results The caro-tid intima-media thickness(IMT)was increased to 0.23 cm,while coronary flow velocity reserve(CFVR)was decreased to 1.57,and mode-rate mitral regurgitation was found in the proband.The genetic alteration G→A change at 1 448 of exon 10 causing premature stop codon(W462X).The same heterozygous nonsense mutation was also found in his father.The mutation had been reported in other Chinese patients.In vitro experiments showed that W462X mutation leads to low LDL binding and internalization ability.Conclusions The homozygous mutation(W462X)in exon 10 of the LDL-r gene were identified in the clinically heterozygous FH proband.The W462X mutation is the underl-ying cause of hypercholesterolaemia and clinical AS manifestations.W462X is recurrent mutation among Chinese FH patients.It might be a hot spot mutation in LDL-r in Chinese FH.J Appl Clin Pediatr,2009,24(1):18-20