A new study, was published today in Jama Cardiology, by scientists at deCODE genetics/Amgen and collaborators in Denmark and the USA, on the genetics of accessory conduction pathways in the heart (Wolff-Parkinson-White syndrome). The study reveals that accessory pathways can cause rhythm disturbances, characterized by an overly fast heartbeat, which can be life-threatening.
Accessory pathways are found among around 0.3% of individuals, but their prevalence is likely higher as a majority of them do not cause symptoms that lead to diagnosis. It is believed that other factors can influence the likelihood of developing rhythm disturbances in the presence of accessory pathways.
The results of the genetic study showed that three sequence variants, two in the gene CCDC141 and one in the gene SCN10A, affect the accessory pathways and consequent rhythm disturbances. The variants are common, with frequencies ranging from 3-62%. The variants are also associated with increased conduction velocity in the atria of the heart, and heart rate regulation, supporting the notion that these factors influence the risk of rhythm disturbances among those with accessory pathways.
While medical therapy can reduce the risk of rhythm disturbances, the only definitive treatment for accessory pathways is to ablate the pathway. This procedure is not without risk; therefore risk assessment is a key factor in treatment choice. Knowledge about the genetics of accessory pathways and their consequences is limited, but such information could prove useful for risk assessment.