KCNQ1 and Hypokalemia: Moreover, most patients with acquired LQTS have one or more risk factors, such as advanced age, female sex, hypopotassemia, latent congenital LQTS, and polypharmacy.[19] In our elderly female patient, the QT interval was slightly prolonged at 1 year prior (Fig. 1), and diagnostic genetic testing for LQTS revealed the p.Ala283Val missense variant in KCNQ1.