AIM: Our aim was to examine the diagnostic yield of genetic testing in 855 consecutive unrelated cases referred for Long QT syndrome (LQTS). RESULTS: Eight hundred fifty five consecutive patients with a mean age at testing of 27.5±18.6 years, were referred for LQTS genetic testing and had accompanying clinical information. KCNQ1, KCNH2, SCN5A, ANK2, KCNE1, KCNE2, CACNA1C, KCNJ2, CAV3, and SCN4B were analyzed using Next-Generation sequencing in all patients, and 395 patients were also tested for an additional two genes, AKAP9 and SNTA1. We retrospectively analyzed the diagnostic yield of this genetic test and factors that predicted the likelihood of a disease causing mutation using ANOVA, χ2, t-test, and receiver operator curves. At least one mutation was identified in 30.3% of the patients (n=259), and 18 patients (2.1%) had two mutations. Patients with two mutations had a longer QTc interval (p<0.01) than patients with one mutation. A longer QTc duration and family history of LQTS were each associated with a higher yield of positive results on genetic testing (p<0.01 for each). Using a QTc cutoff of 476 msec or greater, the genetic testing had a sensitivity of 72% and a specificity of 49%. Mutations within the transmembrane domain of KCNQ1 were associated with a greater risk of cardiac arrest and syncope relative to mutations in other domains of the gene. Mutations in SCN5A were associated with a higher frequency of cardiac arrest (52.6%). CONCLUSION: Sequencing-based genetic testing has a sensitivity of 72% and has clinical utility.
AIM: Our aim was to examine the diagnostic yield of genetic testing in 855 consecutive unrelated cases referred for Long QT syndrome (LQTS). RESULTS: Eight hundred fifty five consecutive patients with a mean age at testing of 27.5±18.6 years, were referred for LQTS genetic testing and had accompanying clinical information. KCNQ1, KCNH2, SCN5A, ANK2, KCNE1, KCNE2, CACNA1C, KCNJ2, CAV3, and SCN4B were analyzed using Next-Generation sequencing in all patients, and 395 patients were also tested for an additional two genes, AKAP9 and SNTA1. We retrospectively analyzed the diagnostic yield of this genetic test and factors that predicted the likelihood of a disease causing mutation using ANOVA, χ2, t-test, and receiver operator curves. At least one mutation was identified in 30.3% of the patients (n=259), and 18 patients (2.1%) had two mutations. Patients with two mutations had a longer QTc interval (p<0.01) than patients with one mutation. A longer QTc duration and family history of LQTS were each associated with a higher yield of positive results on genetic testing (p<0.01 for each). Using a QTc cutoff of 476 msec or greater, the genetic testing had a sensitivity of 72% and a specificity of 49%. Mutations within the transmembrane domain of KCNQ1 were associated with a greater risk of cardiac arrest and syncope relative to mutations in other domains of the gene. Mutations in SCN5A were associated with a higher frequency of cardiac arrest (52.6%). CONCLUSION: Sequencing-based genetic testing has a sensitivity of 72% and has clinical utility.
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Authors: James Rush Priest; Charles Gawad; Kristopher M Kahlig; Joseph K Yu; Thomas O'Hara; Patrick M Boyle; Sridharan Rajamani; Michael J Clark; Sarah T K Garcia; Scott Ceresnak; Jason Harris; Sean Boyle; Frederick E Dewey; Lindsey Malloy-Walton; Kyla Dunn; Megan Grove; Marco V Perez; Norma F Neff; Richard Chen; Katsuhide Maeda; Anne Dubin; Luiz Belardinelli; John West; Christian Antolik; Daniela Macaya; Thomas Quertermous; Natalia A Trayanova; Stephen R Quake; Euan A Ashley Journal: Proc Natl Acad Sci U S A Date: 2016-09-28 Impact factor: 11.205
Authors: James R Priest; Scott R Ceresnak; Frederick E Dewey; Lindsey E Malloy-Walton; Kyla Dunn; Megan E Grove; Marco V Perez; Katsuhide Maeda; Anne M Dubin; Euan A Ashley Journal: Heart Rhythm Date: 2014-06-25 Impact factor: 6.343