BRAT1-related disorders: phenotypic spectrum and phenotype-genotype correlations from 97 patients.

BRAT1 biallelic variants are associated with rigidity and multifocal seizure syndrome, lethal neonatal (RMFSL), and neurodevelopmental disorder associating cerebellar atrophy with or without seizures syndrome (NEDCAS). To date, forty individuals have been reported in the literature. We collected clinical and molecular data from 57 additional cases allowing us to study a large cohort of 97 individuals and draw phenotype-genotype correlations.

Genotypes and phenotypes heterogeneity in PIK3CA-related overgrowth spectrum and overlapping conditions: 150 novel patients and systematic review of 1007 patients with PIK3CA pathogenetic variants.

Background: Postzygotic activating variants cause several phenotypes within the -related overgrowth spectrum (PROS). Variant strength, mosaicism level, specific tissue involvement and overlapping disorders are responsible for disease heterogeneity. We explored these factors in 150 novel patients and in an expanded cohort of 1007 mutated patients, analysing our new data with previous literature to give a comprehensive picture.

DNA methylation episignature testing improves molecular diagnosis of Mendelian chromatinopathies.

Purpose: Chromatinopathies include more than 50 disorders caused by disease-causing variants of various components of chromatin structure and function. Many of these disorders exhibit unique genome-wide DNA methylation profiles, known as episignatures. In this study, the methylation profile of a large cohort of individuals with chromatinopathies was analyzed for episignature detection.

Novel Frameshift Mutation in a Patient Affected by a Syndromic Form of Neurodevelopmental Disorder.

The cohesin complex is a large evolutionary conserved functional unit which plays an essential role in DNA repair and replication, chromosome segregation and gene expression. It consists of four core proteins, SMC1A, SMC3, RAD21, and STAG1/2, and by proteins regulating the interaction between the complex and the chromosomes. Mutations in the genes coding for these proteins have been demonstrated to cause multisystem developmental disorders known as "cohesinopathies".

Whole Exome Sequencing Reveals a Novel In-Frame Deletion in a Boy with Global Developmental Delay, Absent Speech, Dysmorphic Features, and Cerebral Anomalies.

Neurodevelopmental disorders (NDDs) are a group of highly prevalent, clinically and genetically heterogeneous pediatric disorders comprising, according to the Diagnostic and Statistical Manual of Mental Disorders 5th edition (DSM-V), intellectual disability, developmental delay, autism spectrum disorders, and other neurological and cognitive disorders manifesting in the developmental age. To date, more than 1000 genes have been implicated in the etiopathogenesis of NNDs. Among them, (OMIM # 607270) encodes a protein involved in neural migration and neuritogenesis, and causes NNDs with different molecular mechanisms including copy number variations, single or multiple exonic deletion and single nucleotide variants.

Customised next-generation sequencing multigene panel to screen a large cohort of individuals with chromatin-related disorder.

Background: The regulation of the chromatin state by epigenetic mechanisms plays a central role in gene expression, cell function, and maintenance of cell identity. Hereditary disorders of chromatin regulation are a group of conditions caused by abnormalities of the various components of the epigenetic machinery, namely writers, erasers, readers, and chromatin remodelers. Although neurological dysfunction is almost ubiquitous in these disorders, the constellation of additional features characterizing many of these genes and the emerging clinical overlap among them indicate the existence of a community of syndromes.

De novo unbalanced translocations have a complex history/aetiology.

We investigated 52 cases of de novo unbalanced translocations, consisting in a terminally deleted or inverted-duplicated deleted (inv-dup del) 46th chromosome to which the distal portion of another chromosome or its opposite end was transposed. Array CGH, whole-genome sequencing, qPCR, FISH, and trio genotyping were applied. A biparental origin of the deletion and duplication was detected in 6 cases, whereas in 46, both imbalances have the same parental origin.

Report of a patient and further clinical and molecular characterization of interstitial 4p16.3 microduplication.

Background: Pure interstitial duplications of chromosome band 4p16.3 represent an infrequent chromosomal finding with, to the best of our knowledge, only two patients to date reported.

Case Presentation: We report on a 13-year-old boy showing a set of dysmorphic facial features, attention deficit hyperactivity disorders, learning difficulties, speech and cognitive delays, overgrowth and musculoskeletal anomalies in whom an interstitial duplication of about 400 kb in 4p16.