The global distribution of the p.R1193Q polymorphism in the SCN5A gene

• We investigated the frequency of the p.R1193Q polymorphism in the SCN5A gene.
• The p.R1193Q polymorphism is specifically characteristic of Asian populations.
• The p.R1193Q mutant allele may have originated in southern East Asia.

The SCN5A (sodium channel, voltage-gated, type V, alpha subunit) gene encodes the cardiac sodium channel, a member of the voltage-gated sodium channel family. The p.R1193Q (c.3578G>A) polymorphism in SCN5A is known to accelerate inactivation of the sodium channel current, and has been identified in patients with Brugada and long QT syndromes. In the present study, we investigated the frequency of the p.R1193Q substitution in more than 4000 genomic DNA samples from 34 Asian, European, and African populations using TaqMan and/or APLP (amplified product length polymorphism) assays. Allele A (p.1193Q) was detected in most Asian populations, but was sporadically observed or absent in European and African populations. These results demonstrated that the p.R1193Q substitution is characteristic of Asian populations.

The distribution of allele A (p.1193Q) frequencies in 29 East and South Asian populations as indicated by the red sector in each pie chart.Figure optionsDownload high-quality image (190 K)Download as PowerPoint slide