A de novo ryanodine receptor 2 gene variant in a case of sudden cardiac death.

A 34-year-old man, who was previously fit and healthy, died suddenly on exercise. A post-mortem exam performed by forensic pathologists and a toxicological screening were normal; therefore, the cause of death was suspected to be sudden arrhythmic death syndrome, prompting the need for a molecular autopsy. Screening for genetic variations underlying arrhythmogenic genes by next-generation sequencing highlighted a heterozygous single-nucleotide variant in the exon n. 94 of the ryanodine receptor type 2 gene. This gene, encoding the cardiac ryanodine receptor, is one of the main genetic variants of catecholaminergic polymorphic ventricular tachycardia, estimated to affect 1 in 10,000 individuals. It manifests with syncope, seizures, or sudden death due to exercise- or emotional stress-induced bidirectional or polymorphic ventricular tachycardia, usually in children and young adults with morphologically normal hearts and normal baseline electrocardiograms. Even if this de novo missense mutation has not yet been associated with catecholaminergic polymorphic ventricular tachycardia, it is likely to be a disease-causing variant which leads to a defective protein responsible for disturbed ion flow.