Some researchers claim that babies should be routinely tested for long QT syndrome (LQTS) by electrocardiogram (ECG) at around 3 weeks of age because it would be cost-effective and save lives. Bottom line. The ECG is neither sensitive nor specific to hereditary LQTS and can be hard to interpret in newborns. Routine ECG screening of newborns remains controversial, but any individual with clinical features of LQTS (eg, syncope with exercise in a young person), an ECG typical of LQTS, or a family history of either LQTS or young sudden death should be referred to a heart rhythm specialist and a genetics clinic. Assessment of individuals, at-risk relatives, and genetic testing should be offered where indicated. The complete Gene Messenger—Long QT Syndrome by the GenetiKit research team is available on CFPlus.* Past Gene Messenger articles can be accessed on-line at www.cfp.ca. On the home page, click on Collections in the left-hand menu, then click on Genetics.