Phenotypic Spectrum of GNA11 R183C Mosaicism.

Background: Many vascular anomalies harbor postzygotic somatic variants in GNAQ and GNA11; however, the phenotype of specific G-protein variants has not been well described. We report the clinical characteristics of 17 patients with a GNA11 R183C variant.

Methods: This case series is derived from a multinational cohort of vascular anomaly patients whose pathogenic mutations were identified using high-depth next generation sequencing.

DNA methylation-array interlaboratory comparison trial demonstrates highly reproducible paediatric CNS tumour classification across 13 international centres.

Aims: DNA methylation profiling, recently endorsed by the World Health Organisation (WHO) as a pivotal diagnostic tool for brain tumours, most commonly relies on bead arrays. Despite its widespread use, limited data exist on the technical reproducibility and potential cross-institutional differences. The LOGGIC Core BioClinical Data Bank registry conducted a prospective laboratory comparison trial with 12 international laboratories to enhance diagnostic accuracy for paediatric low-grade gliomas, focusing on technical aspects of DNA methylation data generation and profile interpretation under clinical real-time conditions.

Hamartoma of mature cardiac myocytes presenting as a polypoid epicardial tumor in the interatrial groove and with gene fusions by copy number anomalies of chromosome 7.

Hamartoma of mature cardiac myocytes (HMCM) is an extremely rare cardiac tumor characterized by benign growth of differentiated mature striated cardiac myocytes, and usually involves the ventricular myocardium. We describe the case of a 15-year-old female who presented with a short history of atrial fibrillation and a polypoid epicardial tumor that was attached to the interatrial groove by a short pedicle. The resected specimen showed features consistent with HMCM.

Assessment of gene-disease associations and recommendations for genetic testing for somatic variants in vascular anomalies by VASCERN-VASCA.

Background: Vascular anomalies caused by somatic (postzygotic) variants are clinically and genetically heterogeneous diseases with overlapping or distinct entities. The genetic knowledge in this field is rapidly growing, and genetic testing is now part of the diagnostic workup alongside the clinical, radiological and histopathological data. Nonetheless, access to genetic testing is still limited, and there is significant heterogeneity across the approaches used by the diagnostic laboratories, with direct consequences on test sensitivity and accuracy.