Nat Genet. 2026 Mar 30. doi: 10.1038/s41588-026-02547-5. Online ahead of print. ABSTRACT Small nuclear RNAs (snRNAs) are essential components of the spliceosome. De novo variants in snRNA genes RNU4-2 (ReNU syndrome), RNU5B-1 and RNU2-2 have been linked to dominant neurodevelopmental disorders (NDDs), revealing a large unexpected contribution of noncoding RNA genes to genetic diseases. Here, through international collaborations, we analyze systematically 200 potentially functional snRNA genes in a French cohort of 34,329 people with rare disorders. We report RNU2-2 variants in 141 individuals, including 35 with recurrent dominant pathogenic variants and 91 affected members from 73 families with biallelic variants. Recessive RNU2-2 NDD is at least twice as frequent as the dominant form and often involves a de novo variant in trans with an inherited allele, consistent with the high mutability of snRNA genes. Dominant and recessive RNU2-2 NDDs share overlapping clinical features, with frequent epilepsy. Blood transcriptomics and DNA methylation analyses revealed subtle, variant-specific effects on splicing and episignatures. Our results support a gradient-of-impact model bridging dominant and recessive inheritance, and establish RNU2-2 variants as a principal contributor to NDDs, nearly as prevalent as ReNU syndrome. PMID:41912934 | DOI:10.1038/s41588-026-02547-5

Nature. 2026 Apr 1. doi: 10.1038/s41586-026-10313-0. Online ahead of print. ABSTRACT The neural crest generates a broad spectrum of cell types that migrate across the body plan to populate multiple tissues¹. However, the relationship between lineages of neural crest derivatives remains unclear, and the extent to which neural crest cells delaminated from the neural tube have specified fates remains debated. Here, leveraging CRISPR barcoding in mice and mosaic variant barcode analysis in humans, we demonstrate robust bilateral progenitor clonal spread of neural crest progenitors along the rostrocaudal axis but limited clonal overlap between sensory and sympathetic lineages. Computational modelling of mosaic variants suggests that most neural crest cells show strong fate restriction before delamination. Real-time imaging of quail embryos further shows a fibroblast-growth-factor-dependent rostrocaudal dispersion of neural crest cells across multiple axial levels. These findings support a model in which neural crest fate bias predominantly emerges within the neural tube, with only a minor subset of delaminated progenitors retaining multipotency to generate both sensory and sympathetic derivatives. PMID:41922758 | DOI:10.1038/s41586-026-10313-0

Trends Genet. 2026 Mar 31:S0168-9525(26)00038-7. doi: 10.1016/j.tig.2026.02.003. Online ahead of print. ABSTRACT The human ASXL gene family consists of ASXL1, ASXL2, and ASXL3, first described as the additional sex combs (Asx) in Drosophila. The encoded proteins scaffold BAP1-mediated histone H2A deubiquitination. ASXL genes are implicated in pre-cancerous, cancerous, and neurodevelopmental conditions. Truncating mutations predominate and were originally predicted to result in protein loss of function (LOF); however, mounting evidence from population genetics and in vitro studies supports gain-of-function (GOF) mechanisms. Sequence analysis suggests that such mechanisms require both escape from nonsense-mediated mRNA decay and removal of a putative C-terminal degron signal within ASXL proteins. We propose GOF as a generalized mechanism for ASXL mutations, resulting in increased protein stability and altered histone modifications, with implications for diagnosis and therapy for these medical conditions. PMID:41925445 | DOI:10.1016/j.tig.2026.02.003

Trends Genet. 2026 Mar 18:S0168-9525(26)00030-2. doi: 10.1016/j.tig.2026.01.011. Online ahead of print. ABSTRACT Spina bifida is a clinically and etiologically heterogeneous group of neural tube defects (NTDs) that includes meningomyelocele. While folic acid (FA) supplementation has reduced the incidence by 30-50%, genetic contributors remain only partially understood. New trio sequencing technology has identified de novo mutations (DNMs) in 20-25% of patients. Two recent large-scale genomic studies identified DNMs in 187 candidate genes and a recurrent 22q11.2 deletion as risk factors. Partial penetrance and variable expressivity are frequent, suggesting that risk is dependent upon FA and other modifiers. The Spina Bifida Sequencing Consortium supports large-scale data sharing for multidisciplinary approaches, emphasizing high-confidence NTD genes and moving the results toward clinical testing. PMID:41850968 | DOI:10.1016/j.tig.2026.01.011

Genet Med. 2026 Mar 16:102551. doi: 10.1016/j.gim.2026.102551. Online ahead of print. ABSTRACT PURPOSE: Biallelic DIAPH1 pathogenic variants cause a neurodevelopmental syndrome occasionally associated with immunodeficiency. This study aims to define the clinical and immunological spectrum of DIAPH1-related neuroimmunological syndrome and explore the gene’s developmental role using vertebrate models. METHODS: 53 individuals with biallelic DIAPH1 variants, including 33 previously unreported patients were studied. Clinical features were analysed and functional studies were conducted using knockout models in Danio rerio and Xenopus tropicalis. RESULTS: Clinical features included developmental delay, intellectual disability, progressive microcephaly, cortical visual impairment or blindness, epilepsy, and frequent occipital-predominant brain abnormalities. Almost half suffered from infections, mainly affecting their respiratory tract related to epilepsy and aspiration. Although the majority had normal lymphocyte subsets and serum immunoglobulins, T-cell receptor excision circles and naïve T-lymphocyte counts were consistently low. The Xenopus model mirrored growth and eye defects seen in humans, while zebrafish exhibited no overt malformations but showed seizure-like behaviour in Phenothiazine assays. CONCLUSIONS: DIAPH1 is critical for neurodevelopment, immune regulation, and DNA repair. The DNA repair defect may influence susceptibility to infection, lymphoma, or treatment-related toxicity. Although absolute T-cell numbers are not consistent with SCID, impaired T-cell maturation suggests these patients could be identified by TREC newborn screening before neurological symptoms develop. PMID:41860019 | DOI:10.1016/j.gim.2026.102551

N Engl J Med. 2026 Mar 12;394(11):1142. doi: 10.1056/NEJMc2518638. NO ABSTRACT PMID:41812208 | DOI:10.1056/NEJMc2518638

Eur J Pediatr. 2026 Mar 11;185(4):175. doi: 10.1007/s00431-026-06801-0. ABSTRACT Alazami syndrome is a neurodevelopmental disorder characterized by postnatal growth retardation, moderate to severe intellectual disability, and facial dysmorphology. It is caused by biallelic variants in the transcriptional regulator La ribonucleoprotein 7 (LARP7), where frameshift variants accounted for the majority of cases. The current study presents 7 new patients, including 3 males and 4 females from 3 unrelated families. Careful and thorough clinical examination identified novel oro-dental disease abnormalities, including a prominent premaxilla and enamel defects. The detected variants (c.1113_1116del, c.997 + 2T > C and c.518T > C) were not reported in the previous studies. The substitution c.518T > C represented the second missense variant to be identified in patients with Alazami syndrome. Male patients from the three families fulfilled ≥ 2 clinical warning signs of primary immunodeficiency. Lymphocyte subset counts and immunoglobulin levels were estimated in patients from two families. The values were within reference ranges, with only minor non-significant alterations in cytotoxic T-cell counts. A functional assay of B lymphocyte response was performed in one family, demonstrating impaired Streptococcus pneumoniae IgG antibody production following Pneumovax vaccination in the male patient, while his female sibling mounted an adequate response. In conclusion, the disease has a wide range of symptoms, which vary greatly among the affected patients. Our study expanded the clinical and molecular spectrum of the disorder and highlighted immunodeficiency as an underrecognized disease feature, potentially with a male sex predilection. PMID:41811398 | DOI:10.1007/s00431-026-06801-0

bioRxiv [Preprint]. 2026 Mar 2:2026.02.27.708546. doi: 10.64898/2026.02.27.708546. ABSTRACT Extrachromosomal DNA (ecDNA) is a major driver of oncogene amplification, tumour heterogeneity and poor clinical outcomes [1-3], yet its detection relies on specialised genomic assays that are not integrated into routine diagnostics. Here, we show that ecDNA status can be inferred directly from standard haematoxylin and eosin-stained whole-slide pathology images. We develop an end-to-end, weakly supervised deep learning framework that aggregates thousands of high-magnification patches per slide with slide-level augmentation and interpretable attention. Across twelve cancer types from The Cancer Genome Atlas, the approach identifies tumours with genomic amplifications and, critically, distinguishes ecDNA-amplified from chromosomally amplified or non-amplified tumours, with the strongest signal in glioblastoma. Attention maps localise regions enriched for nuclei with altered chromatin intensity and texture, and predicted ecDNA status recapitulates its adverse association with survival. These results indicate that ecDNA amplifications leave reproducible histomorphologic foot-prints detectable by routine pathology, enabling scalable screening to prioritise tumours for confirmatory molecular testing. PMID:41847039 | PMC:PMC12991143 | DOI:10.64898/2026.02.27.708546

Genet Med. 2026 Jan;28(1):101618. doi: 10.1016/j.gim.2025.101618. Epub 2025 Oct 24. ABSTRACT PURPOSE: For decades, the selection of disorders included in newborn screening (NBS) programs has been guided by principles published by Wilson and Jungner in 1968. As research explores the expansion of conditions included in NBS through genomic sequencing, there is a critical need for updated recommendations to address the opportunities and complexities of genomic data. METHODS: The International Consortium on Newborn Sequencing includes leaders from over 16 research projects investigating genomic NBS across the United Kingdom, Europe, United States, and Oceania. Consortium members were invited to participate in a modified Delphi study, aggregating opinion on the selection of conditions for genomic NBS through 3 rounds of online questionnaires, with feedback provided to participants between rounds. RESULTS: In round 1, 94 participants completed the questionnaire, and 10 of 43 statements reached consensus. In round 2, 81 participants completed the questionnaire, and 14 of 27 statements reached consensus. In round 3, 68 participants completed the questionnaire, and all 10 statements reached 72% or more consensus. CONCLUSION: The 10 consensus recommendations developed in this study can guide future research and public health programs performing genomic NBS. This process also identified key areas of participant discordance, highlighting important topics for future research. PMID:41765866 | PMC:PMC12950953 | DOI:10.1016/j.gim.2025.101618

Am J Hum Genet. 2026 Jan 15:S0002-9297(25)00482-3. doi: 10.1016/j.ajhg.2025.12.011. Online ahead of print. ABSTRACT ASTN1 encodes astrotactin 1, a neuronal-glial ligand in the developing brain that promotes neuronal migration along radial glia in brain structures with laminar organization, such as the cerebral cortex, hippocampus, and cerebellum. In mouse models, disruption of Astn1 results in neuronal migration deficits, a mild reduction in cerebellar volume, and balance and coordination deficits. In humans, bi-allelic ASTN1 variants have been identified in nine individuals with neurodevelopmental disorders (NDDs) with or without brain malformations. ASTN1 additionally interacts with astrotactin 2 (ASTN2) to implement neuronal migration; ASTN2 deletions associate with NDDs with reduced penetrance. Here, we describe eighteen individuals with NDDs from twelve unrelated families with bi-allelic, ultra-rare, predicted damaging variants in ASTN1 and one individual with heterozygous variants in both ASTN1 and ASTN2. We expand the clinical phenotypic descriptions of ASTN1-related NDDs, which range from mild to profound developmental delay or intellectual disability and can be associated with autism, attention-deficient hyperactivity disorder (ADHD), and epilepsy. Other recurrent abnormalities include dysmorphic facial features, hypotonia, spasticity, and ataxia. Additionally, we add to the neuroradiographic phenotype of this condition, which can be normal, mildly dysmorphic (a thin corpus callosum and cerebellar dysgenesis), or severely dysmorphic (polymicrogyria and lissencephaly). Remarkably, three genetic models of multilocus pathogenic variation (MPV), including tri-allelic, double heterozygous, and double homozygous due to distributive absence of heterozygosity (AOH), were observed. This ASTN1 allelic series characterizes the consequences of perturbations in radial-glia-guided neuronal migration in humans, the phenotypic spectrum of ASTN1-related NDDs, and the contribution of MPV to the genetic basis of NDDs. PMID:41544630 | DOI:10.1016/j.ajhg.2025.12.011