تغییرات نوکلئوتیدی ژن‌های CoxII، سیتوکروم b و tRNAGlu میتوکندریایی در بیماران ایرانی مبتلا به سندرم بروگادا (آریتمی قلبی)

Introduction: The Brugada syndrome (BrS) belongs to cardiac arrhythmia disorders that is seen on the echocardiogram bands and is a significant cause of sudden death in young adults. At the molecular level, mechanisms that contribute to BrS are mutations in genes that encode for ion channels. It has been reported that the activity of ion channels in cardiomyocytes is sensitive to ATP level. This study aimed to clarify the relationship between variations in mtDNA and the development of BrS. Methods: single strand conformation polymorphism (SSCP) was used for rapid screening of mtDNA mutations in CoxII, Cytb and tRNAGlu genes in a family with 5 patients and 15 sporadic patients. DNA fragments showing abnormal banding patterns were sequenced for identification of exact mutations. Results: One new mutation (T8258C) was found in Cox II gene in family members that caused to change phenylalanine amino acid to leucine. In sporadic patients, three different new mutations were also found including a homoplasmic mutation (T14687C) in tRNAGlu gene, a heteroplasmic mutation (G14838A) and a homoplasmic C14766T mutation. Conclusions: Since the mitochondrion's ATP synthesis is important in heart and this mutation was not identified in control samples, it is possible that these mutations could constitute a predisposing factor that in combination with environmental factors may trigger in patients with BrS.