SSCP screening of mutation in exon 13 of low density lipoprotein receptor gene in Chinese familial hypercholesterolemia patients

Objective To investigate the application of polymerase chain reaction and single strand conformation polymorphism analysis(PCR-SSCP)to the screening of gene mutation of exon 13 of the LDLR gene in familial hypercholesterolemia(FH).Methods Peripheral blood DNA of 16 clinically diagnosed FH patients was extracted and the exon 13 coding region of the LDLR gene was amplified by PCR.PCR products were separated by optimized SSCP electrophoresis and visualized by silver staining.DNA fragments with abnormal mobility were sequenced to determine the nature and position of mutations.Results The SSCP electrophoresis conditions were optimized as 8%polyaerylamide(degree of cross linking 49:1)gel without glycerin at a electrophoresis temperature of 10℃ or 8%polyacrylamide gel with 5%glycerin at room temperature,gel thickness of＜0.4 mm,and a voltage of 5 V/cm.DNA fragments were well resolved with the conditions and sequencing of the abnormal bands resuhed in detections of missense mutations of A606T,D601N,Y601D and G636V together with a synonymous mutation of 1959C→T in 4 patients and a sole synonymous mutation of 1959C→T in other 4 patients.Conclusion PCR-SSCP is an effective method for the screening of exon13 mutations of LDLR gene in FH patients. Key words: Hypercholesterolemia,familial;  Receptors,LDL;  Exons; Point mutation; Polymorphism,single-stranded conformational; Polymerase chain reaction