LONG QT INTERVAL IN TURNER SYNDROME – A HIGH PREVALENCE OF LQTS GENE MUTATIONS

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: MON 796-817-Diabetes Genetics & Epidemiology
Translational
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-796
Christian Trolle*1, Kristian Havmand Mortensen2, Lisbeth Nørum Pedersen1, Agnethe Berglund1, Henrik Kjærulf Jensen1, Niels Holmark Andersen1 and Claus H. Gravholt1
1Aarhus University Hospital, Aarhus, Denmark, 2Cambridge University Hospitals, Cambridge, United Kingdom
Background: QT interval prolongation of unknown etiology is common in Turner syndrome (TS). This study set out to explore the presence of known pathogenic long QT (LQT) mutations in TS and to examine the corrected QT interval (QTc) over time and relate the findings to the TS phenotype.

Methods and Results: Adult females with TS (n=102) were examined thrice with a mean follow-up of 4.7±0.5 years, and 68 age-matched healthy controls were examined once. QTc was measured by one blinded reader (intra-reader variability: 0.7%), and adjusted for influence of heart rate by Bazett’s (bQTc) and Hodges’s formula (hQTc). The prevalence of mutations in genes related to Long QT syndrome (LQTS) was determined in females with TS and a QTc >432.0 milliseconds (ms). Echocardiographic assessment of aortic valve morphology, 24-hour blood pressures and blood samples were done.

The mean hQTc in females with TS (414.0±25.5 ms) compared to controls (390.4±17.8 ms) was prolonged (p<0.001) and did not change over time (416.9±22.6 vs. 415.6±25.5 ms; p=0.4).  45,X karyotype was associated with increased hQTc prolongation compared to other TS karyotypes (418.2±24.8 vs. 407.6±25.5 ms; p=0.03). In females with TS and a bQTc >432 ms, 7 had mutations in major LQTS-genes (SCN5A and KCNH2) and one in a minor LQTS-gene (KCNE2).

Conclusion: The prevalence of mutations in major LQTS genes was strikingly high for females with TS and the longest QTc interval.

Clinical Trial Registration: NCT00624949. https://register.clinicaltrials.gov/prs/app/action/SelectProtocol/sid/S0001FLI/selectaction/View/ts/3/uid/U000099E

Nothing to Disclose: CT, KHM, LNP, AB, HKJ, NHA, CHG

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm

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