A Duplication Mutation in KCNQ1 Gene in Romano-Ward Syndrome

ABSTRACT Romano-Ward syndrome (RWS, Long QT syndrome 1) is a rare familial congenital cardiac disorder characterized by a prolonged QT interval on electrocardiograph. RWS may occur due to the mutations in KCNQ1 gene. Our case was a 27-year-old male patient with post-exercise syncope attacks and pre-syncope chest pain. QT interval was 660 ms on ECG. The KCNQ1 gene was sequenced and a heterozygous twelve base duplication was identified that causes a non-frameshift insertion of four new amino acids (QRQK) in the protein chain between amino acids 262-263. The patient was prescribed with metoprolol and cardioverter defibrillator was implanted. The patient was followed-up and he was discharged. Keywords: Long QT syndrome, KCNQ1, Romano-Ward syndrome OZET Romano-Ward sendromu (RWS, Uzun QT sendromu 1) EKG’de uzamis QT araligi ile karakterize bir ailevi konjenital kalp hastaligidir. RWS KCNQ1 genindeki mutasyonlarla olusabilmektedir. 27 yasindaki erkek hastamizda senkop oncesi gogus agrilari ve efor sonrasi senkop ataklari vardi. EKG’de 660 milisaniyeyi bulan QT intervalleri vardi. Sekans analizinde 262-263. aminoasitler arasina giren 4 (QRQK) aminoasit ile olusan ve cerceve kaymasi yapmayan 12 bazlik bir heterozigot mutasyon tespit edildi. Hastaya metoprolol recete edildi ve cardioverter defibrilator implante edildi. Takiplerin ardindan hasta taburcu edildi.