Postmortem diagnosis of left dominant arrhythmogenic cardiomyopathy: the importance of a multidisciplinary network for sudden death victims. “HIC mors gaudet succurere vitae”

Filamin C (FLNC) truncating mutation in a fatal arrhythmogenic left ventricular cardiomyopathy (ALVC)

Forensic pathologists are frequently asked to investigate cases of sudden death (SD), and identifying the cause of death can be of particular importance, especially where it may be necessary to perform family screening among the relatives of the victim. A multidisciplinary approach inclusive of genetic analysis is therefore strongly recommended. According to forensic practice, arrhythmogenic cardiomyopathy (ACM) is a well-known cause of SD. However, cases of SD caused by a left ventricular pattern of ACM diagnosed at autopsy are rarely reported in the literature. We present the case of an apparently healthy, 37-year-old male found dead at his home. At autopsy, multiple foci of epicardial and mid-wall fibrous and fibro-adipose tissue were observed within the left ventricle and, to a lesser extent, within the interventricular septum. Toxicology was negative, whereas a filamin C truncating mutation was detected through genetic analysis. To our knowledge, this is the first instance of arrhythmogenic left ventricular cardiomyopathy being diagnosed at autopsy.

New Insights on Molecular Autopsy in Sudden Death: A Systematic Review

Sudden unexpected deaths often remain unresolved despite forensic examination, posing challenges for pathologists. Molecular autopsy, through genetic testing, can reveal hidden causes undetectable by standard methods. This review assesses the role of molecular autopsy in clarifying SUD cases, examining its methodology, utility, and effectiveness in autopsy practice. This systematic review followed PRISMA guidelines and was registered with PROSPERO (registration number: CRD42024499832). Searches on PubMed, Scopus, and Web of Science identified English studies (2018-2023) on molecular autopsy in sudden death cases. Data from selected studies were recorded and filtered based on inclusion/exclusion criteria. Descriptive statistics analyzed the study scope, tissue usage, publication countries, and journals. A total of 1759 publications from the past 5 years were found, with 30 duplicates excluded. After detailed consideration, 1645 publications were also excluded, leaving 84 full-text articles for selection. Out of these, 37 full-text articles were chosen for analysis. Different study types were analyzed. Mutations were identified in 17 studies, totaling 47 mutations. Molecular investigations are essential when standard exams fall short in determining sudden death causes. Expertise in molecular biology is crucial due to diverse genetic conditions. Discrepancies in post-mortem protocols affect the validity of results, making standardization necessary. Multidisciplinary approaches and the analysis of different tissue types are vital.

Arrhythmogenic left ventricular cardiomyopathy caused by a novel likely pathogenic DSP mutation, p.K1165Rfs*8, in a family with sudden cardiac death

OBJECTIVE

We conducted an investigation into the clinical and molecular characteristics of Arrhythmogenic left ventricular cardiomyopathy (ALVC) caused by a novel likely pathogenic mutation in an Iranian pedigree with sudden cardiac death (SCD).

BACKGROUND

ALVC is a genetically inherited myocardial disease characterized by the substitution of fibro-fatty tissue in the left ventricular myocardium, predominantly inherited in an autosomal dominant pattern and is commonly associated with genes involved in encoding desmosomal proteins, specifically Desmoplakin (DSP).

METHODS

The patient and available family members underwent a comprehensive clinical assessment, including Cardiac magnetic resonance (CMR) imaging, along with Whole-exome sequencing (WES). The identified variant was confirmed and segregated by Polymerase chain reaction (PCR) and Sanger sequencing in the family members.

RESULTS

A novel likely pathogenic heterozygous variant, DSP (NM_004415.4), c.3492_3498del, p.K1165Rfs*8 was discovered in the proband. This variant is likely to be the primary reason for ALVC in this specific family. This variant was confirmed by Sanger sequencing and segregated in other affected members of the family.

CONCLUSION

We identified a novel likely pathogenic variant in the DSP gene, which has been identified as the cause of ALVC in an Iranian family. Our investigation underscores the importance of genetic testing, specifically WES, for individuals suspected of ALVC and have a family history of SCD.

Genetic Background and Clinical Features in Arrhythmogenic Left Ventricular Cardiomyopathy: A Systematic Review

In recent years a phenotypic variant of Arrhythmogenic cardiomyopathy has been described, characterized by predominant left ventricular (LV) involvement with no or minor right ventricular abnormalities, referred to as Arrhythmogenic left ventricular cardiomyopathy (ALVC). Different disease-genes have been identified in this form, such as Desmoplakin (DSP), Filamin C (FLNC), Phospholamban (PLN) and Desmin (DES). The main purpose of this critical systematic review was to assess the level of knowledge on genetic background and clinical features of ALVC. A search (updated to April 2022) was run in the PubMed, Scopus, and Web of Science electronic databases. The search terms used were “arrhythmogenic left ventricular cardiomyopathy” OR “arrhythmogenic cardiomyopathy” and “gene” OR “arrhythmogenic dysplasia” and “gene”. The most represented disease-gene turned out to be DSP, accounting for half of published cases, followed by FLNC. Overall, ECG abnormalities were reported in 58% of patients. Major ventricular arrhythmias were recorded in 26% of cases; an ICD was implanted in 29% of patients. A total of 6% of patients showed heart failure symptoms, and 15% had myocarditis-like episodes. DSP is confirmed to be the most represented disease-gene in ALVC patients. An analysis of reported clinical features of ALVC patients show an important degree of electrical instability, which frequently required an ICD implant. Moreover, myocarditis-like episodes are common.

Pitfalls in arrhythmogenic left ventricular cardiomyopathy (ALVC). A review of the literature with considerations on a single case of sudden death in a juvenile athlete

Sudden cardiac death (SCD) in young athletes represents a challenging issue in forensic practice. The pathologist is frequently asked to establish the cause of death basing upon anatomical findings and to evaluate the role of the physician in preparticipation evaluation (PPE) and eligibility decision. Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a leading cause of SCD during sport activity. However, in the last few years, forms with predominant or even isolated involvement of the left ventricle (LV) have progressively been correlated with a high risk of SCD. We present a case of SCD in an apparently healthy 19-year-old semi-professional football player. Annual PPEs performed in accordance with international and Italian recommendations, were unremarkable. At autopsy, a 1-cm area of subepicardial fibro-fatty replacement was observed at the postero-lateral wall of the LV. The finding was diagnostic of arrhythmogenic left ventricular cardiomyopathy (ALVC). A review of this rare pathology has been performed under a forensic perspective, focusing on the evaluation of the medico-legal responsibility of the physician in the PPE and on the morphological aspects of the disease. Current diagnostic criteria and recommendations result to be focused on the right ventricular pattern, with a risk of misdiagnosis for isolated LV forms. Furthermore, few detailed autopsies cases concerning ALVC have been published. There is a need, therefore, to study this rare disease with a careful and revised approach.