Primary carnitine deficiency as a potential cause of short QT syndrome

Congenital forms of short QT syndrome (SQTS) are associated with QT interval abbreviation on the electrocardiogram, with atrial and ventricular arrhythmias and with an increased risk of sudden death. Whilst mutations in a number of ion channel and transporter genes have been identified in SQTS patients, often the underlying basis of the condition is not identified. This article briefly surveys evidence that primary carnitine deficiency (PCD), which arises from mutations in the SLC22A5 gene, may be a cause of SQTS. Experimental evidence linking carnitine deficiency with accelerated repolarization is also discussed and a case made for the imperative for further work to understand underlying mechanisms of low-carnitine induced repolarization abbreviation.