Genetic investigations of sudden unexpected deaths in infancy using next-generation sequencing of 100 genes associated with cardiac diseases

Abstract

Sudden infant death syndrome (SIDS) is the most frequent manner of post-perinatal death among infants. One of the suggested causes of the syndrome is inherited cardiac diseases, mainly channelopathies, that can trigger arrhythmias and sudden death. The purpose of this study was to investigate cases of sudden unexpected death in infancy (SUDI) for potential causative variants in 100 cardiac-associated genes. We investigated 47 SUDI cases of which 38 had previously been screened for variants in RYR2, KCNQ1, KCNH2 and SCN5A. Using the Haloplex Target Enrichment System (Agilent) and next-generation sequencing (NGS), the coding regions of 100 genes associated with inherited channelopathies and cardiomyopathies were captured and sequenced on the Illumina MiSeq platform. Sixteen (34%) of the SUDI cases had variants with likely functional effects, based on conservation, computational prediction and allele frequency, in one or more of the genes screened. The possible effects of the variants were not verified with family or functional studies. Eight (17%) of the SUDI cases had variants in genes affecting ion channel functions. The remaining eight cases had variants in genes associated with cardiomyopathies. In total, one third of the SUDI victims in a forensic setting had variants with likely functional effect that presumably contributed to the cause of death. The results support the assumption that channelopathies are important causes of SUDI. Thus, analysis of genes associated with cardiac diseases in SUDI victims is important in the forensic setting and a valuable supplement to the clinical investigation in all cases of sudden death.

Natural and Undetermined Sudden Death: Value of Post-Mortem Genetic Investigation

“…Our higher percentage may be due to a comprehensive genetic analysis including both genes associated with channelopathies and genes associated with cardiomyopathies, recently associated with arrhythmic pathologies without any structural alteration [52, 53]. In concordance with our results, recent studies performed in post-mortem samples using NGS technology showed percentages of rare variants potentially pathogenic in 30%-40% of samples analyzed [24–26, 54–58]. …”

A comprehensive next‐generation sequencing assay for the diagnosis of epidermolysis bullosa

“…We also found EBSEQ to have high analytical reliability of 99% for base substitutions and small deletions and duplication and clinical sensitivity of 75% to 98%. EBSEQ was used in this study primarily to identify mutations in undiagnosed patients, although even when the clinical phenotype is typical of a specific diagnosis, we are studying the type and location and ultimately the consequences of these mutations to increase understanding and predict clinical severity and prognosis . Tenedini and colleagues recently published a similar NGS assay on 10 patients, and there is a report of a commercial laboratory (GeneDx, Gaithersburg, MD, USA) using whole‐exome sequencing to screen for EB .…”

“…Target DNA was captured, amplified, and purified based on fragment size. The Haloplex Target Enrichment System for Illumina was used for library preparation. Probes were designed using Agilent's web‐based SureSelect Custom Design portal.…”

Post-mortem investigation of young deceased individuals with ischemic heart disease—outcome of supplementary genetic testing for dyslipidemia

“…Genetic testing as part of the forensic investigation has proven to be beneficial in, for example, suspected cases of sudden cardiac death [13][14][15]. However, only few studies have used NGS for post-mortem genetic investigations [16][17][18][19][20]. We aimed to investigate the diagnostic outcome for FH by broader genetic screening using NGS in a post-mortem setting in individuals with IHD.…”

“…The relevant DNA regions were isolated by a capture method using the custom design of the Haloplex Target Enrichment system (Agilent Technologies, CA, USA) with 150-bp read lengths [20]. The design included all coding exons, 25 bp of adjacent introns as well as 5′-and 3′-UTR regions of the eight investigated genes to a total size of 51, 941 bp.…”