Premium
The Prevalence of Mutations in KCNQ1, KCNH2, and SCN5A in an Unselected National Cohort of Young Sudden Unexplained Death Cases
Author(s) -
WINKEL BO GREGERS,
LARSEN MAIKEN KUDAHL,
BERGE KNUT ERIK,
LEREN TROND PAUL,
NISSEN PETER HENRIK,
OLESEN MORTEN SALLING,
HOLLEGAARD MADS VILHELM,
JESPERSEN THOMAS,
YUAN LEI,
NIELSEN NIKOLAJ,
HAUNSØ STIG,
SVENDSEN JESPER HASTRUP,
WANG YINMAN,
KRISTENSEN INGRID BAYER,
JENSEN HENRIK KJÆRULF,
TFELTHANSEN JACOB,
BANNER JYTTE
Publication year - 2012
Publication title -
journal of cardiovascular electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.193
H-Index - 138
eISSN - 1540-8167
pISSN - 1045-3873
DOI - 10.1111/j.1540-8167.2012.02371.x
Subject(s) - medicine , sudden death , cohort , population , genetic testing , long qt syndrome , sudden cardiac death , pediatrics , disease , cohort study , qt interval , environmental health
Sudden unexplained death account for one‐third of all sudden natural deaths in the young (1–35 years). Hitherto, the prevalence of genopositive cases has primarily been based on deceased persons referred for postmortem genetic testing. These deaths potentially may represent the worst of cases , thus possibly overestimating the prevalence of potentially disease causing mutations in the 3 major long‐QT syndrome (LQTS) genes in the general population. We therefore wanted to investigate the prevalence of mutations in an unselected population of sudden unexplained deaths in a nationwide setting. Methods: DNA for genetic testing was available for 44 cases of sudden unexplained death in Denmark in the period 2000–2006 (equaling 33% of all cases of sudden unexplained death in the age group). KCNQ1, KCNH2, and SCN5A were sequenced and in vitro electrophysiological studies were performed on novel mutations. Results: In total, 5 of 44 cases (11%) carried a mutation in 1 of the 3 genes corresponding to 11% of all investigated cases (R190W KCNQ1, F29L KCNH2 (2 cases), P297S KCNH2 and P1177L SCN5A ). P1177L SCN5A has not been reported before. In vitro electrophysiological studies of P1177L SCN5A revealed an increased sustained current suggesting a LQTS phenotype. Conclusion: In a nationwide setting, the genetic investigation of an unselected population of sudden unexplained death cases aged 1–35 years finds a lower than expected number of mutations compared to referred populations previously reported. We therefore conclude that the prevalence of mutations in the 3 major LQTS associated genes may not be as abundant as previously estimated. (J Cardiovasc Electrophysiol, Vol. 23 pp. 1092‐1098, October 2012)