A novel SCN5A gene mutation (del D1790) associated with congenital long QT syndrome.

Objective To explore SCN5A gene mutations in Chinese patients with congenital long QT syndrome type 3 (LQT3). Methods Three patients who had been screened as KCNQ1 and KCNH2 gene mutations but did not have mutations in the two genes,and whose electrocardiograms were consistent with the electrocardiographic features of LQT3 were chosen for the study. The exons in the functional regions of SCN5A gene were amplified with polymerase chain reaction and the amplified products were sequenced with Sanger method. If the proband was found to have a mutation, his family members would be screened for the mutation too. Results A heterozygous mutation was found in one family. Three nucleotides (GAC) deletion mutation that caused aspartic acid deletion in codon 1790 in SCN5A gene exon 28 was identified in the proband and her mother. Conclusion A novel SCN5A gene mutation is identified in a Chinese family with LQTS, which expands the spectrum of SCN5A mutations associated diseases.