Comprehensive analysis of CNOT3-related neurodevelopmental disorders: phenotypic and genotypic characterization.

The CCR4-NOT complex, crucial in gene expression regulation, includes CNOT3, a subunit linked to neurodevelopmental disorders when mutated. This study investigates 51 patients from 42 families with heterozygous CNOT3 variants, aiming to expand the understanding of CNOT3-related neurodevelopmental disorders and explore genotype-phenotype correlations. Patients originated from various countries, reflecting the disorder's global significance.

MBOAT7 encephalopathy: Characterizing the neurology and epileptology.

Objective: Biallelic pathogenic MBOAT7 variants are associated with neurodevelopmental disorders, intellectual disability (ID), epilepsy, and neuropsychiatric disorders such as attention-deficit/hyperactivity disorder and autism spectrum disorders. We aimed to characterize the epilepsy phenotype in a cohort of patients affected by this syndrome.

Methods: We describe epilepsy features, electroencephalography, magnetic resonance imaging (MRI) findings, antiseizure treatment response, and neurodevelopment of 15 patients with biallelic MBOAT7 variants.

Mapping variants in thyroid hormone transporter MCT8 to disease severity by genomic, phenotypic, functional, structural and deep learning integration.

Predicting and quantifying phenotypic consequences of genetic variants in rare disorders is a major challenge, particularly pertinent for 'actionable' genes such as thyroid hormone transporter MCT8 (encoded by the X-linked SLC16A2 gene), where loss-of-function (LoF) variants cause a rare neurodevelopmental and (treatable) metabolic disorder in males. The combination of deep phenotyping data with functional and computational tests and with outcomes in population cohorts, enabled us to: (i) identify the genetic aetiology of divergent clinical phenotypes of MCT8 deficiency with genotype-phenotype relationships present across survival and 24 out of 32 disease features; (ii) demonstrate a mild phenocopy in ~400,000 individuals with common genetic variants in MCT8; (iii) assess therapeutic effectiveness, which did not differ among LoF-categories; (iv) advance structural insights in normal and mutated MCT8 by delineating seven critical functional domains; (v) create a pathogenicity-severity MCT8 variant classifier that accurately predicted pathogenicity (AUC:0.91) and severity (AUC:0.

Koolen-de Vries Syndrome: a journey from diagnosis to treatments.

The Koolen-de Vries Syndrome Foundation was founded in 2013 with the mission to educate, increase awareness, promote research and develop treatments for individuals living with Koolen-de Vries Syndrome (KdVS) and their families. With this aim, the foundation has focused on: developing scientific resources through patient cell and animal models, providing seed funding to basic and clinical researchers, establishing a natural history study of KdVS and increasing patient engagement. Projects have been prioritized across these areas of focus with an emphasis on expanding international research on KdVS, supporting translational research, establishing an international natural history study and conducting studies to assess patient priorities.

A new blood DNA methylation signature for Koolen-de Vries syndrome: Classification of missense KANSL1 variants and comparison to fibroblast cells.

Pathogenic variants in KANSL1 and 17q21.31 microdeletions are causative of Koolen-de Vries syndrome (KdVS), a neurodevelopmental syndrome with characteristic facial dysmorphia. Our previous work has shown that syndromic conditions caused by pathogenic variants in epigenetic regulatory genes have identifiable patterns of DNA methylation (DNAm) change: DNAm signatures or episignatures.

Ocular manifestations in Koolen-de Vries syndrome: an international study.

Objectives: Koolen-de Vries Syndrome (KdVS) is a rare multisystem neurodevelopmental disorder. Ocular manifestations, including strabismus, ptosis, and hyperopia, have been reported in KdVS patients, but detailed clinical data are limited. This study aims to investigate the already known ocular malformations and their frequency while uncovering novel ocular associations.

CAMTA1-related disorder: Phenotypic and molecular characterization of 26 new individuals and literature review.

Calmodulin-binding transcriptional activator 1 (CAMTA1) is highly expressed in the brain and plays a role in cell cycle regulation, cell differentiation, regulation of long-term memory, and initial development, maturation, and survival of cerebellar neurons. The existence of human neurological phenotypes, including cerebellar dysfunction with variable cognitive and behavioral abnormalities (CECBA), associated with CAMTA1 variants, has further supported its role in brain functions. In this study, we phenotypically and molecularly characterize the largest cohort of individuals (n = 26) with 23 novel CAMTA1 variants (frameshift-7, nonsense-6, splicing-1, initiation codon-1, missense-5, and intragenic deletions-3) and compare the findings with all previously reported cases (total = 53).

The Human Phenotype Ontology in 2024: phenotypes around the world.

The Human Phenotype Ontology (HPO) is a widely used resource that comprehensively organizes and defines the phenotypic features of human disease, enabling computational inference and supporting genomic and phenotypic analyses through semantic similarity and machine learning algorithms. The HPO has widespread applications in clinical diagnostics and translational research, including genomic diagnostics, gene-disease discovery, and cohort analytics. In recent years, groups around the world have developed translations of the HPO from English to other languages, and the HPO browser has been internationalized, allowing users to view HPO term labels and in many cases synonyms and definitions in ten languages in addition to English.

Deep phenotyping of the neuroimaging and skeletal features in KBG syndrome: a study of 53 patients and review of the literature.

Background: KBG syndrome is caused by haploinsufficiency of and is characterised by macrodontia of upper central incisors, distinctive facial features, short stature, skeletal anomalies, developmental delay, brain malformations and seizures. The central nervous system (CNS) and skeletal features remain poorly defined.

Methods: CNS and/or skeletal imaging were collected from molecularly confirmed individuals with KBG syndrome through an international network.

Clinical and radiological assessment of scoliosis in Koolen-de Vries syndrome.

The Koolen-de Vries syndrome (KdVS) is a multisystem disorder characterized by developmental delay, intellectual disability, characteristic facial features, epilepsy, cardiovascular and urogenital malformations, and various musculoskeletal disorders. Scoliosis is a common feature. The aim of this study is to fill the gap in the current knowledge about scoliosis in individuals with KdVS and to provide recommendations for management and follow-up.

GenIDA, a participatory patient registry for genetic forms of intellectual disability provides detailed caregiver-reported information on 237 individuals with Koolen-de Vries syndrome.

Purpose: GenIDA is an international patient registry for individuals diagnosed with intellectual disability, autism spectrum disorder, and/or epilepsy, which is based on an online questionnaire that is completed by parent caregivers. In this study, the GenIDA data on Koolen-de Vries syndrome (KdVS) was analyzed illustrating the value of GenIDA and patient/caregiver participation in rare genetic neurodevelopmental disorders (NDDs).

Methods: Recruitment was done on the GenIDA website from November 2016 to February 2022.

Expanding the speech and language phenotype in Koolen-de Vries syndrome: late onset and periodic stuttering a novel feature.

Speech and language impairment is core in Koolen-de Vries syndrome (KdVS), yet only one study has examined this empirically. Here we define speech, language, and functional/adaptive behaviour in KdVS; while deeply characterising the medical/neurodevelopmental phenotype in the largest cohort to date. Speech, language, literacy, and social skills were assessed using standardised measures, alongside an in-depth health and medical questionnaire.

GenIDA: an international participatory database to gain knowledge on health issues related to genetic forms of neurodevelopmental disorders.

Intellectual disability with or without manifestations of autism and/or epilepsy affects 1-2% of the population, and it is estimated that more than 30-50% of these cases have a single genetic cause. More than 1000 genes and recurrent chromosomal abnormalities are involved in these genetic forms of neurodevelopmental disorders, which often remain insufficiently described in terms of clinical spectrum, associated medical problems, etc., due to their rarity and the often-limited number of patients' phenotypes reported.

In-depth characterisation of a cohort of individuals with missense and loss-of-function variants disrupting .

Background: Heterozygous disruptions of were the first identified molecular cause for severe speech disorder: childhood apraxia of speech (CAS), and yet few cases have been reported, limiting knowledge of the condition.

Methods: Here we phenotyped 28 individuals from 17 families with pathogenic -only variants (12 loss-of-function, five missense variants; 14 males; aged 2 to 62 years). Health and development (cognitive, motor, social domains) were examined, including speech and language outcomes with the first cross-linguistic analysis of English and German.

The performance of genome sequencing as a first-tier test for neurodevelopmental disorders.

Genome sequencing (GS) can identify novel diagnoses for patients who remain undiagnosed after routine diagnostic procedures. We tested whether GS is a better first-tier genetic diagnostic test than current standard of care (SOC) by assessing the technical and clinical validity of GS for patients with neurodevelopmental disorders (NDD). We performed both GS and exome sequencing in 150 consecutive NDD patient-parent trios.