How Often Is SIDS Due to Long-QT Syndrome?

Perhaps 10% of the time, according to a genetics study conducted in Norway

After the neonatal period, the leading cause of mortality before age 1 in developed countries is sudden infant death syndrome (SIDS). Among the potential causes of SIDS are respiratory abnormalities, neurologic disease, and cardiac arrhythmias. To determine how often long-QT syndrome (LQTS) is implicated in SIDS, researchers conducted postmortem genetic studies of 201 SIDS cases and 182 controls (45 infants who did not die of SIDS and 137 adults who died of noncardiac causes) in Norway.

Twenty-six SIDS cases (12.9%) were carriers of LQTS gene variants, and 19 (9.5%) had LQTS variants that were likely contributors to SIDS, according to functional analysis. The gene variants implicated most often were in SCN5A (LQTS3), KCNQ1 (LQTS1), and KCNH2…

Reviewing Author

Mark S. Link, MD