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Sudden cardiac death (SCD) is by definition unexpected and cardiac in nature. The investigation is almost invariably performed by a forensic pathologist. Under these circumstances the role of the forensic pathologist is twofold: (1.) to determine rapidly and efficiently the cause and manner of death and (2.) to initiate a multidisciplinary process in order to prevent further deaths in existing family members. If the death is determined to be due to "natural" causes the district attorney in charge often refuses further examinations. However, additional examinations, i.e. extensive histopathological investigations and/or molecular genetic analyses, are necessary in many cases to clarify the cause of death. The Swiss Society of Legal Medicine created a multidisciplinary working group together with clinical and molecular geneticists and cardiologists in the hope of harmonising the approach to investigate SCD. The aim of this paper is to close the gap between the Swiss recommendations for routine forensic post-mortem cardiac examination and clinical recommendations for genetic testing of inherited cardiac diseases; this is in order to optimise the diagnostic procedures and preventive measures for living family members. The key points of the recommendations are (1.) the forensic autopsy procedure for all SCD victims under 40 years of age, (2.) the collection and storage of adequate samples for genetic testing, (3.) communication with the families, and (4.) a multidisciplinary approach including cardiogenetic counselling.

Sudden arrhythmic death syndrome (SADS) in young individuals is a devastating and tragic event often caused by an undiagnosed inherited cardiac disease. Although post-mortem genetic testing represents a promising tool to elucidate potential disease-causing mechanisms in such autopsy-negative death cases, a variant interpretation is still challenging, and functional consequences of identified sequence alterations often remain unclear. Recently, we have identified a novel heterozygous missense variant (N1774H) in the Nav1.5 channel-encoding gene SCN5A in a 19-year-old female SADS victim. The aim of this study was to perform a co-segregation analysis in family members of the index case and to evaluate the functional consequences of this SCN5A variant. Functional characterization of the SCN5A N1774H variant was performed using patch-clamp techniques in TsA-201 cell line transiently expressing either wild-type or variant Nav1.5 channels. Electrophysiological analyses revealed that variant Nav1.5 channels show a loss-of-function in the peak current densities, but an increased late current compared to the wild-type channels, which could lead to both, loss- and gain-of-function respectively. Furthermore, clinical assessment and genetic testing of the relatives of the index case showed that all N1774H mutation carriers have prolonged QT intervals. The identification of several genotype and phenotype positive family members and the functional implication of the SCN5A N1774H variant support the evidence of the in silico predicted pathogenicity of the here reported sequence alteration. [ABSTRACT FROM AUTHOR]