Molecular Heterogeneity in Pediatric Malignant Rhabdoid Tumors in Patients With Multi-Organ Involvement.

Rhabdoid tumors (RTs) of the brain (atypical teratoid/rhabdoid tumor; AT/RT) and extracranial sites (most often the kidney; RTK) are malignant tumors predominantly occurring in children, frequently those with germline alterations. Here we present data from seven RTs from three pediatric patients who all had multi-organ involvement. The tumors were analyzed using a multimodal molecular approach, which included exome sequencing of tumor and germline comparator and RNA sequencing and DNA array-based methylation profiling of tumors.

Detection of brain somatic variation in epilepsy-associated developmental lesions.

Objective: Epilepsy-associated developmental lesions, including malformations of cortical development and low-grade developmental tumors, represent a major cause of drug-resistant seizures requiring surgical intervention in children. Brain-restricted somatic mosaicism has been implicated in the genetic etiology of these lesions; however, many contributory genes remain unidentified.

Methods: We enrolled 50 children who were undergoing epilepsy surgery into a translational research study.

Maternal mosaicism for a missense variant in the gene that causes Snyder-Robinson syndrome.

There is increasing recognition for the contribution of genetic mosaicism to human disease, particularly as high-throughput sequencing has enabled detection of sequence variants at very low allele frequencies. Here, we describe an infant male who presented at 9 mo of age with hypotonia, dysmorphic features, congenital heart disease, hyperinsulinemic hypoglycemia, hypothyroidism, and bilateral sensorineural hearing loss. Whole-genome sequencing of the proband and the parents uncovered an apparent de novo mutation in the X-linked gene.

Clinical response to dabrafenib plus trametinib in a pediatric ganglioglioma with p.T599dup mutation.

In this follow-up report, we present updated information regarding a previously reported pediatric patient with a World Health Organization grade I ganglioglioma harboring a p.T599dup mutation ( 4: a002618). This patient, based on our initial finding, is receiving combination targeted therapy with a selective BRAF inhibitor (dabrafenib) plus MEK inhibitor (trametinib).