OBJECTIVE: To perform PCR-based site-directed mutagenesis of a new SCN5A 
mutation (K317N) identified in a Chinese family with Brugada syndrome and 
construct the recombinant expression plasmid pRc/CMV-Hh1 containing the human 
cardiac sodium channel alpha subunit (hH1), mutant cDNA.
METHODS: A pair of primers was designed according to the restricted sites Sse 
8387I and Age I of the SCN5A sequence with the mismatches introduced into 
primers. Mutagenesis was performed in a single-step PCR, and the fragments 
amplified by PCR containing the mutation site were subcloned into the 
pRc/CMV-hH1 vector.
RESULTS: Sequence analysis confirmed the presence of the desired mutation site, 
and a mutation from K (Lys) to N (Asn) in codon 317 was identified in the SCN5A 
gene, indicating the successful induction of the mutation at K317N of the SCN5A 
gene.
CONCLUSION: PCR site-directed mutagenesis is accurate and highly efficient, and 
the successfully constructed recombinant expression plasmid pRc/CMV-hH1 (K317N) 
may provide a molecular basis for further functional and genomic investigation 
of SCN5A.