Efficacy of pharmacological treatment and genetic characterization in early diagnosed patients affected by long QT syndrome with impaired AV conduction

Long QT syndrome with AV Wenckebaching & bundle branch block in a neonate

We present a case of 21-day-old neonate brought with history of 3 episodes of syncope. Evaluation revealed congenital long QT syndrome associated with long cycle atypical AV Wenkebaching with a long short cycle sequence related left bundle branch aberrancy. Syncope was attributed to multiple episodes of Torsades de Pointes, necessitating emergency epicardial pacemaker implantation. In addition, child was started on oral propranolol therapy. On 2 months follow up, child was stable with no ventricular high rate episodes during pacemaker interrogation.

Yield and clinical significance of genetic screening in elite and amateur athletes

AIMS

The purpose of this study was to assess the value of genetic testing in addition to a comprehensive clinical evaluation, as part of the diagnostic work-up of elite and/or amateur Italian athletes referred for suspicion of inherited cardiac disease, following a pre-participation screening programme.

METHODS

Between January 2009-December 2018, of 5892 consecutive participants, 61 athletes were investigated: 30 elite and 31 amateur athletes. Elite and amateur athletes were selected, on the basis of clinical suspicion for inherited cardiac disease, from two experienced centres for a comprehensive cardiovascular evaluation. Furthermore, the elite and amateur athletes were investigated for variants at DNA level up to 138 genes suspected to bear predisposition for possible cardiac arrest or even sudden cardiac death.

RESULTS

Of these 61 selected subjects, six (10%) had diagnosis made possible by a deeper clinical evaluation, while genetic testing allowed a definite diagnosis in eight (13%). The presence of >3 clinical markers (i.e. family history, electrocardiogram and/or echocardiographic abnormalities, exercise-induced ventricular arrhythmias) was associated with a higher probability of positive genetic diagnosis (75%), compared with the presence of two or one clinical markers (14.2%, 8.1%, respectively, p-value = 0.004).

CONCLUSION

A combined clinical and genetic evaluation, based on the subtle evidence of clinical markers for inherited disease, was able to identify an inherited cardiac disease in about one-quarter of the examined athletes.

DNA sequence capture and next-generation sequencing for the molecular diagnosis of genetic cardiomyopathies

Hypertrophic cardiomyopathy is a relatively frequent disease with a prevalence of 0.2% worldwide and a remarkable genetic heterogeneity, with more than 30 causative genes reported to date. Current PCR-based strategies are inadequate for genomic investigations involving many candidate genes. Here, we report a next-generation sequencing procedure associated with DNA sequence capture that is able to sequence 202 cardiomyopathy-related genes simultaneously. We developed a complementary data analysis pipeline to select and prioritize genetic variants. The overall procedure can screen a large number of target genes simultaneously, thereby potentially revealing new disease-causing and modifier genes. By using this procedure, we analyzed hypertrophic cardiomyopathy patients in a shorter time and at a lower cost than with current procedures. The specificity of the next-generation sequencing-based procedure is at least as good as other techniques routinely used for mutation searching, and the sensitivity is much better. Analysis of the results showed some novel variants potentially involved in the pathogenesis of hypertrophic cardiomyopathy: a missense mutation in MYH7 and a nonsense variant in INS-IGF2 (patient 1), a splicing variant in MYBPC3 and an indel/frameshift variant in KCNQ1 (patient 2), and two concomitant variations in CACNA1C (patient 3). Sequencing of DNA from the three patients within a pool allowed detection of most variants identified in each individual patient, indicating that this approach is a feasible and cost-effective procedure.