Search

Background Arrhythmogenic cardiomyopathy is a genetically-inherited cardiomyopathy. PKP2 mutations are the most common cause of the disease, associated with conventional ARVC phenotype. Case presentation We presented a 14 years old sportswoman admitted to our emergency department for cardiac arrest-related to ventricular fibrillation. The patient was asymptomatic leading up to cardiac arrest. At admission, she met the diagnosis of AC with bi-ventricular involvement (T negative waves in V1-V6 and inferior leads; severe biventricular dysfunction with fibrofatty replacement involving both ventricles). Family history revealed that her cousin, a 15 years competitive athlete, received a recent diagnosis of ARVC, wherein pathogenetic variant p.Tyr857_Lys859 in heterozygosity in the PKP2 gene was found. As expected, the index case presented the same mutations in PKP2 gene, and no other mutations were found. Implanted cardioverter defibrillator (ICD) and strength follow-up, including heart failure management, was performed. Cascade screening of family members allowed us to identify 19 mutations carriers. Of these, 5 patients were identified to have disease expression. The first to be studied was her 9 years old sister, who involved in high level of sport activities. She presented abnormal ECG with negative T waves in V2-V4, significance burden of premature ventricular complex (PVC >500/24 h) with mild right ventricle dilatation. Of others family members, four patients presented early signs of myocardial disease and significant arrhythmias burden. Except for one patient, all these members were involved in amateur sport activities. Two members had signs of left ventricle (LV) involvement (inverted T waves in leads V4–V6 and inferior leads, LV wall motion abnormalities and late enhancement), whereas one patient (P3) showed a fulfilled ARVD. Three patients presented significant PVC on 24-hour ambulatory ECG monitoring (PVC >500/24 h) (P2, P3 and P5). The arrhythmic burden was more pronounced in two young patients having a sports activity (P2 and P3). This trend was also confirmed at exercise testing. Except for one patient, these findings appear to be related to sport activity, even if this is no high-intensity activity. Among other carriers of pathogenic mutation, three patients showed ECG abnormalities in infero-lateral leads and significance PVC at 24-hour ECG monitoring in absence of other findings related-cardiomyopathy. All family members carried PKP2 mutation were restricted in sports activities, and, in patients presented early disease and arrhythmogenic burden, treatment with beta-blockers was started. Conclusion In this family presenting PKP2 mutation, heterogenicity of disease expression and a close relationship with sport activity was found. This large family case encourages future ACM studies to better understand disease expression and their relationship with sports activity across the entire ACM phenotypic spectrum and ages. Also, this case underscores the importance of early familiar screening, including children involved high-level of sports activity.

In pleiotropic diseases, multiple organ systems are affected causing a variety of clinical manifestations. Here, we report a pleiotropic disorder with a unique constellation of neurological, endocrine, exocrine, and haematological findings that is caused by biallelic MADD variants. MADD, the mitogen-activated protein kinase (MAPK) activating death domain protein, regulates various cellular functions, such as vesicle trafficking, activity of the Rab3 and Rab27 small GTPases, tumour necrosis factor-α (TNF-α)-induced signalling and prevention of cell death. Through national collaboration and GeneMatcher, we collected 23 patients with 21 different pathogenic MADD variants identified by next-generation sequencing. We clinically evaluated the series of patients and categorized the phenotypes in two groups. Group 1 consists of 14 patients with severe developmental delay, endo- and exocrine dysfunction, impairment of the sensory and autonomic nervous system, and haematological anomalies. The clinical course during the first years of life can be potentially fatal. The nine patients in Group 2 have a predominant neurological phenotype comprising mild-to-severe developmental delay, hypotonia, speech impairment, and seizures. Analysis of mRNA revealed multiple aberrant MADD transcripts in two patient-derived fibroblast cell lines. Relative quantification of MADD mRNA and protein in fibroblasts of five affected individuals showed a drastic reduction or loss of MADD. We conducted functional tests to determine the impact of the variants on different pathways. Treatment of patient-derived fibroblasts with TNF-α resulted in reduced phosphorylation of the extracellular signal-regulated kinases 1 and 2, enhanced activation of the pro-apoptotic enzymes caspase-3 and -7 and increased apoptosis compared to control cells. We analysed internalization of epidermal growth factor in patient cells and identified a defect in endocytosis of epidermal growth factor. We conclude that MADD deficiency underlies multiple cellular defects that can be attributed to alterations of TNF-α-dependent signalling pathways and defects in vesicular trafficking. Our data highlight the multifaceted role of MADD as a signalling molecule in different organs and reveal its physiological role in regulating the function of the sensory and autonomic nervous system and endo- and exocrine glands.

Aims The recent American College of Cardiology and American Heart Association Guidelines on hypertrophic cardiomyopathy (HCM) have confirmed surgical myectomy as the gold standard for non-pharmacological treatment of obstructive HCM. However, during the last 15 years, an extensive use of alcohol septal ablation has led to the virtual extinction of myectomy programmes in several European countries. Therefore, many HCM candidates for myectomy in Europe cannot be offered the option of this procedure. The purpose of our study is to report the difficulties and results in developing a myectomy programme for HCM in a centre without previous experience with this procedure. Methods and results The clinical course is reported of 124 consecutive patients with obstructive HCM and heart failure symptoms who underwent myectomy at a single European centre between 1996 and 2010. The median follow-up was 20.3 months (inter-quartile range: 3.9–40.6 months). No patients were lost to follow-up. A cumulative incidence of HCM-related death after myectomy was 0.8, 3.3, and 11.2% at 1, 5, and 10 years, respectively, including one operative death (procedural mortality 0.8%). The left ventricular (LV) outflow gradient decreased from 95 ± 36 mmHg before surgery to 12 ± 6 mmHg at most recent evaluation ( P < 0.001), with none of the patients having a significant residual LV outflow gradient. Of the 97 patients in New York Heart Association functional class III–IV before surgery, 93 (96%) were in class I–II at most recent evaluation ( P < 0.001). Conclusion Our results show that the development of a myectomy programme at a centre without previous experience with this procedure is feasible and can lead to highly favourable clinical results.