Molecular autopsy in young sudden cardiac death victims with suspected cardiomyopathy

Цель исследования: поиск причинных мутаций в генах-кандидатах внезапной сердечной смерти (ВСС) у мужчин, умерших в возрасте до 45 лет. Группа ВСС (30 образцов) была сформирована c использованием критериев ВСС ВОЗ и Европейского общества кардиологов. Средний возраст 31,3±5,3 года. Геномную ДНК выделяли из ткани миокарда методом фенол-хлороформной экстракции. Выполнили секвенирование клинического экзома. На первом этапе проанализировали результаты секевнирования 16 генов, мутации в которых приводят к ССЗ, ассоциированным с повышенным риском ВСС: KCNQ1, KCNH2, SCN5A, AKAP9, ANK2, CACNA1C, CALM1, CALM2, CAV3, KCNE1, KCNE2, KCNJ2, KCNJ5, SCN4B, SNTA1, SCN10A. Из 30 образцов с ВСС при анализе результатов секвенирования 16 генов было обнаружено 6 вероятно патогенных миссенс-мутаций в 7 образцах (23,3 %). В гене SCN10A обнаружено 2 мутации, в KCNH2, KCNE1, AKAP9, SNTA1 - по одной мутации. Подводя первые итоги пилотного исследования ВСС можно сделать следующие предварительные выводы: необходимо продолжение исследований в области молекулярной аутопсии в России, для повышения результативности поиска причинных мутаций, желательны снижение возраста случаев ВСС включаемых в исследование, а также работа с семьями умерших ВСС. Objective: Search for causal mutations in candidate genes for sudden cardiac death (SCD) in men who die before the age of 45. Materials and methods. The SCD group (30 samples) was formed using the criteria for sudden cardiac death of the WHO and the European Society of Cardiology. The average age is 31,3±5,3 years. Genomic DNA was isolated from myocardial tissue using phenol-chloroform extraction. Clinical exome sequencing was performed. At the first stage, the results of sequencing of 16 genes were analyzed, mutations in which result in CVD associated with an increased risk of SCD: KCNQ1, KCNH2, SCN5A, AKAP9, ANK2, CACNA1C, CALM1, CALM2, CAV3, KCNE1, KCNE2, KCNJ5, KCNJ5, SNTA1, SCN10A. Results. Of 30 samples with SCD, when analyzing the results of sequencing 16 genes, 6 probably pathogenic missense mutations were found in 7 samples (23.3%). 2 mutations were found in the SCN10A gene, one mutation in KCNH2, KCNE1, AKAP9, SNTA1. Findings. Summing up the first results of a pilot SCD study, the following preliminary conclusions can be drawn: it is necessary to continue research in the field of molecular autopsy in Russia, in order to increase the effectiveness of the search for causative mutations, it is desirable to reduce the age of SCD cases included in the study, as well as work with families of deceased SCD.

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P1107First results of molecular autopsy examinations in sudden cardiac death drawn from nationwide multidisciplinary and multicentric collaboration in the Czech Republic

EP Europace ◽

10.1093/europace/euaa162.147 ◽

2020 ◽

Vol 22 (Supplement_1) ◽

Author(s):

A Krebsova ◽

P Votypka ◽

P Peldova ◽

K Rucklova ◽

A Pilin ◽

...

Keyword(s):

Cardiac Arrest ◽

Czech Republic ◽

Sudden Cardiac Death ◽

Dna Sequencing ◽

Cardiac Death ◽

Positive Family History ◽

Molecular Autopsy ◽

The Czech Republic ◽

Pathogenic Variants ◽

Custom Made

Abstract Funding Acknowledgements Supported by Ministry of Health of the Czech Republic, grant nr. NV18-02-00237. All rights reserved." Introduction "Molecular autopsy" in sudden cardiac death (SCD) is an important diagnostic tool for primary prevention of cardiac arrest in victim´s relatives and requires multicentric and multidisciplinary collaboration. Purpose To establish a national network for SCD diagnostics, to assess the acceptance of genetic testing in at risk relatives and to elucidate the genetic etiology of SCD in a representative Czech cohort aged below 45 years. Patients and Methods Between 2016 and 2019 we ascertained 70 SCD (50 M / 20 F), with positive family history for cardiac arrest in 8/70 cases. Only one family did not agree with molecular autopsy. Genetic counselling and cardiological screening examination was carried out in first degree relatives of SCD survivors accompanied by custom-made targeted panel massively parallel DNA sequencing comprising 100 cardiac conditions-related genes. Presence of pathogenic variants was validated by Sanger DNA sequencing and through family segregation analyses. Results According to post-mortem diagnosis most victims died of HCM (17/70), ACM (16/70), no structural heart disease was found in 15/70 cases, DCM/LVNC in 9/70, 6/70 were SIDS cases, other rare diagnoses comprised aortic dissection, or myocarditis. Most of victims died at sleep, only 9/70 victims died during strenuous activities. About 50% of SCD victims did not have cardiac complaints before death. Very likely or certain molecular etiology (i.e. based on presence of ACMG.net Class 4 to 5 variants) was disclosed in 12/70 (17%) in RYR2, FLNC, TTN, KCNH2 and KCNQ1 genes, whilst potentially causative DNA variants (Classes 3-4) were observed in 13/70 (18%) cases. In SIDS we did not find any pathogenic variants. Interestingly, the KCNE1 p.Asp85Asn (LQT 5 lite) variant, was detected in 3/70 cases as a recognized risk factor for ventricular arrhythmias. Conclusion The multidisciplinary cooperation in Czech Republic has been established, family survivors are willing to receive genetic and cardiological care, while centralised molecular genetic analysis enables reliable results which are in accordance with other multicentric studies. The molecular autopsy should, especially in SIDS, be expanded to whole exome sequencing.

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