Can Heterozygous Mutations Be a Risk Factor for Sudden Cardiac Death?

Aysun Fatma Akkuş, Ömer Ferudun Akkuş, Servet Altay

Keywords: sudden cardiac death, heterozygous mutations

Introduction:

Sudden cardiac death is defined as natural death due to cardiac causes, which is manifested by sudden loss of consciousness within one hour after the onset of acute symptoms. There are genetic diseases that predispose to sudden cardiac death. Genetic diseases should be investigated, especially in families with sudden cardiac death at a young age.

Case:

47 years old male patient, the patient has no known history of chronic illness. The patient, who was arrested at home, underwent cardiopulmonary resuscitation for 35 minutes and was brought to the emergency room after defibrillation twice due to ventricular fibrillation. In the electrocardiography of the intubated unconscious patient, the rhythm was atrial fibrillation and the QTc distance was 610 msec, ST segment elevation in the AVR leads, ST segment depression in the other leads was detected . Troponin T (hs-cTnT) level was found to be 837 ng / l. No pathology was found in the radiological examinations. The patient was taken to the coronary angiography laboratory for diagnostic purposes and normal coronary arteries were detected. It was learned that the father of the patient died at the age of 40 due to sudden cardiac arrest. Long QT syndrome was considered in the patient. Genetic analysis revealed heterozygous RyR2 and heterozygous TTN gene mutations in the patient.

Discussion:

It has been shown in the literature that mutations in RyR2 and TTN can cause various ventricular arrhythmias and diseases . In this case report, no homozygous mutation was found, but the presence of two different heterozygous mutations related to sudden cardiac death may have contributed to the development of sudden cardiac death. In cases with risk factors for sudden cardiac death (family history, unexplained syncope, brugada pattern in ECG, etc.), heterozygous mutations should be included in risk scoring.

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