Adaptive behavior and psychiatric comorbidities in KCNB1 encephalopathy.

Aim: KCNB1 encephalopathy encompasses a broad phenotypic spectrum associating intellectual disability, behavioral disturbances, and epilepsies of various severity. Using standardized parental questionnaires, we aimed to capture the heterogeneity of the adaptive and behavioral features in a series of patients with KCNB1 pathogenic variants.

Methods: We included 25 patients with a KCNB1 encephalopathy, aged from 3.

Stankiewicz-Isidor syndrome: expanding the clinical and molecular phenotype.

Purpose: Haploinsufficiency of PSMD12 has been reported in individuals with neurodevelopmental phenotypes, including developmental delay/intellectual disability (DD/ID), facial dysmorphism, and congenital malformations, defined as Stankiewicz-Isidor syndrome (STISS). Investigations showed that pathogenic variants in PSMD12 perturb intracellular protein homeostasis. Our objective was to further explore the clinical and molecular phenotypic spectrum of STISS.

Loss-of-function variants in ARHGEF9 are associated with an X-linked intellectual disability dominant disorder.

ARHGEF9 defects lead to an X-linked intellectual disability disorder related to inhibitory synaptic dysfunction. This condition is more frequent in males, with a few affected females reported. Up to now, sequence variants and gross deletions have been identified in males, while only chromosomal aberrations have been reported in affected females who showed a skewed pattern of X-chromosome inactivation (XCI), suggesting an X-linked recessive (XLR) disorder.

Further delineation of the clinical spectrum of de novo TRIM8 truncating mutations.

De novo mutations of the TRIM8 gene, which codes for a tripartite motif protein, have been identified using whole exome sequencing (WES) in two patients with epileptic encephalopathy (EE), but these reports were not sufficient to conclude that TRIM8 was a novel gene responsible for EE. Here we report four additional patients presenting with EE and de novo truncating mutations of TRIM8 detected by WES, and give further details of the patient previously reported by the Epi4K consortium. Epilepsy of variable severity was diagnosed in children aged 2 months to 3.

IQSEC2-related encephalopathy in males and females: a comparative study including 37 novel patients.

Purpose: Variants in IQSEC2, escaping X inactivation, cause X-linked intellectual disability with frequent epilepsy in males and females. We aimed to investigate sex-specific differences.

Methods: We collected the data of 37 unpublished patients (18 males and 19 females) with IQSEC2 pathogenic variants and 5 individuals with variants of unknown significance and reviewed published variants.

Recessive mutations in ATP8A2 cause severe hypotonia, cognitive impairment, hyperkinetic movement disorders and progressive optic atrophy.

Background: ATP8A2 mutations have recently been described in several patients with severe, early-onset hypotonia and cognitive impairment. The aim of our study was to characterize the clinical phenotype of patients with ATP8A2 mutations.

Methods: An observational study was conducted at multiple diagnostic centres.

Early-onset encephalopathy with paroxysmal movement disorders and epileptic seizures without hemiplegic attacks: About three children with novel ATP1A3 mutations.

Objective: Heterozygous mutations in the ATP1A3 gene are responsible for various neurological disorders, ranging from early-onset alternating hemiplegia of childhood to adult-onset dystonia-parkinsonism. Next generation sequencing allowed the description of other phenotypes, including early-onset epileptic encephalopathy in two patients. We report on three more patients carrying ATP1A3 mutations with a close phenotype and discuss the relationship of this phenotype to alternating hemiplegia of childhood.

NR4A2 haploinsufficiency is associated with intellectual disability and autism spectrum disorder.

NR4A2, a member of the nuclear receptor superfamily, is involved in modulation of target gene transcription, regulating several developmental processes such as regulation of cellular homeostasis, neuronal development, inflammation and carcinogenesis. 2q24.1 deletions are extremely rare, and only 1 patient with a de novo deletion encompassing only NR4A2 gene was reported so far.

[Changes in clinical practice related to the arrival of next-generation sequencing in the genetic diagnosis of developmental diseases].

Introduction: The arrival of high-throughput sequencing (HTS) has led to a sweeping change in the diagnosis of developmental abnormalities (DA) with or without intellectual deficiency (ID). With the prospect of deploying these new technologies, two questions have been raised: the representations of HTS among geneticists and the costs incurred due to these analyses.

Methods: Geneticists attending a clinical genetics seminar were invited to complete a questionnaire.

Bipolar Disorder Type 1 in a 17-Year-Old Girl with Wolfram Syndrome.

Objective: Wolfram syndrome (WS, MIM 222300) is a rare autosomal, recessive neurodegenerative disorder associated with mutations in WFS1, a gene that has been associated with bipolar disorder (BD). WS, characterized by the association of juvenile-onset diabetes mellitus (DM) and bilateral progressive optic atrophy (BPOA), encompasses several other clinical features, including cognitive impairments and psychiatric disorders. Detailed data on the psychiatric phenotype are still scarce, and how WS relates to BD is still unknown.