Objective Fever can trigger seizures in several early-onset epilepsies. SCN1A-related epilepsies, including Dravet Syndrome, are the best characterised conditions in this spectrum, but a growing number of genes implicated in fever-sensitive epilepsies have emerged. We assessed the genetic heterogeneity of individuals who underwent testing because of seizures or epilepsy with fever sensitivity. In particular, we investigated the occurrence of ATP6V0C pathogenic variants and delineated its associated electroclinical features. Methods We retrospectively reviewed individuals tested with epilepsy-targeted Next Generation Sequencing (NGS) panels and/or Whole Exome Sequencing (WES) between 2022 and 2025, selecting those with documented fever sensitivity (defined as seizure occurrence or exacerbation temporally linked to febrile episodes in subjects who suffer from both febrile and afebrile seizures). Variants were filtered for frequency, evaluated through segregation and prediction tools, and classified according to ACMG guidelines. Results Among 721 individuals tested with NGS or WES for neurological indications, 418 (58%) had a history of seizures, including 53 (7.3%) with fever-sensitive epilepsy. Pathogenic or likely pathogenic variants were identified in 30% of these cases. Notably, ATP6V0C variants accounted for 2/16 (12.5%) of all pathogenic/likely pathogenic findings and were identified in 3.8% of tested fever-sensitive epilepsy patients, ranking among the most frequently implicated genes in this cohort. Significance Our findings support ATP6V0C as a relevant gene in the landscape of childhood epilepsies with fever sensitivity. The associated phenotype appears characterized by early febrile-triggered motor seizures, initially normal EEG followed by multifocal abnormalities, normal MRI and subsequent onset of neurodevelopmental impairment. These results highlight the importance of accurate molecular diagnosis in children presenting with fever-sensitive seizures, with potential implications for future precision therapies.

The TP53 gene encodes the well-known p53 tumor suppressor protein, which plays a crucial role in preventing cancer development. Germline TP53 variants cause Li-Fraumeni Syndrome (LFS), an autosomal dominant disorder associated with early-onset cancers, including breast cancer, brain tumors, leukemias, bone cancers, and soft tissue sarcomas. Here, we described a germline TP53 variant c.671A>C, located at the penultimate nucleotide of exon 6 and predicted to result in the missense substitution p.E224A. The variant was identified in a 2-year-old child with retroperitoneal rhabdomyosarcoma and with a strong family history suggestive of LFS. Functional assays in yeast and human cells demonstrated wild type-like activity of the protein p.E224A; however, in silico splicing analysis indicated potential splice defects (e.g., SpliceAI score = 0.77). Given this discrepancy, we further investigated this variant using a minigene approach, demonstrating that it causes the skipping of exon 6, likely resulting in a frameshift and the introduction of a premature stop codon. These findings supported the classification of the TP53 germline variant c.671A>C (p.E224A) as likely pathogenic, providing a definitive molecular diagnosis for family counselling. Additionally, the present results sheds light on how certain predicted TP53 missense variants can be linked to disease mechanisms through RNA splicing disruption.

CONTEXT:Neuroradiological findings in Noonan syndrome (NS) remain insufficiently characterized. OBJECTIVE:To characterize neuroimaging abnormalities in children with genetically confirmed NS and evaluate their associations with clinical phenotype. DESIGN, SETTING, AND PARTICIPANTS:In this multicenter retrospective study, brain MRI scans and longitudinal clinical and genetic data were reviewed from children with genetically confirmed NS evaluated between 2008 and 2023 at seven pediatric endocrinology centers. MAIN OUTCOME MEASURES:Prevalence and spectrum of neuroimaging abnormalities and their associations with genotype and clinical features. RESULTS:The cohort included 130 individuals with NS (71 males; mean age at MRI, 9.7 years), most carrying PTPN11 variants (69.2%). Structural brain abnormalities were identified in 84.7% and included midbrain-hindbrain malformations (69.2%), callosal anomalies (52.3%), cortical malformations (50%), white matter abnormalities (48.4%), and cranio-cervical junction anomalies (40%). Brain tumors and Chiari I malformation were present in 12.3% and 10.7%, respectively. Seizures were associated with cortical tumors (p = 0.02) and callosal anomalies (p = 0.03), whereas developmental delay was associated with callosal anomalies (p = 0.02) and microcephaly (p < 0.01). Follow-up MRI, available in 41 patients over a mean duration of 6.3 years, showed interval changes in 48.7%, including tumor progression, progressive tonsillar descent, odontoid retroversion, and newly detected lesions. CONCLUSIONS:In this selected cohort of children with NS who underwent brain MRI as part of routine clinical care, structural brain abnormalities were frequent and were associated with neurological manifestations. These findings support a role for RAS/MAPK pathway dysregulation in brain development and highlight the clinical value of MRI in selected patients with NS.

OBJECTIVES:This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To evaluate the benefits and harms of using NGS techniques compared to conventional newborn screening alone for pre-symptomatic identification of genetic diseases in newborns. SECONDARY OBJECTIVES:to explore equity and ethical issues in the application of the new techniques, to inform healthcare decisions by families, carers, and policymakers.

Infantile sialic acid storage disorder (ISSD) represents the most severe form of free sialic acid storage disease (FSASD), a rare lysosomal storage disorder caused by mutations in SLC17A5, which encodes the lysosomal sialic acid transporter sialin. These mutations lead to the accumulation of free sialic acid within lysosomes, resulting in multisystemic involvement. Through a case report and literature review, we explored the phenotypic spectrum of FSASD, with a particular focus on neurological manifestations and characteristic neuroimaging findings of ISSD. Our patient exhibited severe hypotonia shortly after birth, dysmorphic features, and hyporegenerative anemia, a clinical presentation that has not previously described in ISSD. Brain MRI revealed hypomyelination, periventricular white matter T1-hyperintensity and T2-hypointensity, callosal thinning, and optic atrophy, providing critical diagnostic clues. MR spectroscopy showed an elevated NAA-like peak, further supporting the suspicion of ISSD. Laboratory tests demonstrated increased chitotriosidase activity and elevated urinary excretion of free sialic acid. Next-generation sequencing identified compound heterozygosity for a known pathogenic variant and a previously unreported SLC17A5 variant (c.709G>A), affecting a highly conserved transmembrane domain residue and predicted to be pathogenic.Our findings underscore the role of neuroimaging in the early diagnosis of ISSD and suggest a potential link between sialic acid metabolism and erythropoiesis, suggesting further investigation. Despite the lack of targeted therapies, recognizing FSASD remains essential for patient management and genetic counselling, ensuring appropriate clinical care and family support.

Introduction:Arteriovenous cerebral high-flow shunts include the vein of Galen aneurysmal malformation (VGAM) and vein of Galen dilatation, which are considered secondary to arteriovenous malformations or arteriovenous fistulas. These entities are often sporadic but are found in association with variants of the RASA1 and EPHB4 genes (capillary malformation-arteriovenous malformation, CMAVM; OMIM #608354) or ACVRL1, ENG, and SMAD4 genes (hereditary hemorrhagic telangiectasia, HHT; OMIM #187300). The clinical phenotypes associated with these conditions are highly variable, with incomplete penetrance and mostly dependent on the hemodynamic consequences (including heart failure and cerebral hemorrhage) or management complications rather than anatomical vascular variations per se. The present study aimed to genetically characterize a cohort of 29 patients affected by arteriovenous cerebral high-flow shunts who were treated at a pediatric referral center. Methods:The genetic techniques employed include next-generation sequencing, multiplex ligation-dependent probe amplification, and whole-exome sequencing. Results:Of the 29 patients, 11 cases were found to have variants in genes associated with vascular functions, five cases received a genetic diagnosis, one case presented with a variant of uncertain significance in the EPHB4 gene, and five cases showed variants in novel genes possibly linked with cerebrovascular disorders. Discussion:We provide extensive case descriptions and attempt to infer the genotype-phenotype correlations; variants in all of the known genes associated with arteriovenous cerebral shunts were reported in VGAM patients, while cutaneous angiomas were specific to RASA1 mutations. The genotypic and phenotypic descriptions of the affected individuals may thus have relevant implications in terms of better pathophysiological understanding, genotype-phenotype correlations, treatment strategies, and outcomes.

BACKGROUND:Distal arthrogryposis with impaired proprioception and touch (DAIPT) is a rare autosomal recessive neurological disease characterized by progressive alteration of mechanosensation. DAIPT is caused by loss of function variants in the PIEZO2 gene that encodes an ionic channel involved in mechanotransduction signaling. Our study started from the case of an 11-year-old boy with skeletal and neuromuscular features suggestive of DAIPT. METHODS:Exome sequencing was performed on the trio. The identified variants in PIEZO2 were validated by Sanger sequencing. Functional assays of the variants were performed by minigene assay in HEK-293 cells and on patient-derived cells using NMD inhibitors. RESULTS:Trio exome sequencing revealed the presence of two novel variants in the PIEZO2 gene: a nonsense variant (c.1924G>T; p.Glu642*) and an intronic variant of uncertain significance (c.2170-15A>G). Functional analysis demonstrated that the intronic variant disrupts splicing, leading to premature stop codon formation and possible mRNA targeting to nonsense-mediated mRNA decay (NMD). Molecular study in patient-derived fibroblasts with specific NMD inhibitors shows that transcripts derived from both alleles are degraded by NMD, thus confirming the effect of the nonsense variant and enabling reclassification of the VUS. CONCLUSION:We present the phenotypic and genetic description of a patient with features suggestive of DAIPT carrying novel biallelic variants in PIEZO2, one of which could be reclassified as pathogenic after functional assays. This study also provides a detailed review of all the published patients with DAIPT and expands the phenotypic and genetic understanding of DAIPT, aiding in diagnosis, genetic counseling, and clinical management.

Nail-Patella syndrome (NPS) is a rare autosomal dominant condition due to haploinsufficiency of LMX1B, caused by loss-of-function variants affecting the coding sequence, or partial/whole deletions of the gene. In here, we describe two familial cases of NPS, carrying novel variants of the LMX1B 5’UTR region (−174C>T and −226G>A). To verify their pathogenic role, we carried out a functional characterization, both by reporter gene assays in heterologous systems and in patient’s derived cells. We demonstrated that both variants impair LMX1B expression at post-transcriptional level. They introduce two upstream open reading frames (uORFs), out-of-frame with the main LMX1B coding sequence, generating transcripts detected by the non-sense mediated decay (NMD). We also demonstrated that the escape of the altered mRNA from NMD, if any, may lead to the synthesis of an aberrant LMX1B protein.

UPF3B encodes the Regulator of nonsense transcripts 3B protein, a core-member of the nonsense-mediated mRNA decay pathway, protecting the cells from the potentially deleterious actions of transcripts with premature termination codons. Hemizygous variants in the UPF3B gene cause a spectrum of neuropsychiatric issues including intellectual disability, autism spectrum disorder, attention deficit hyperactivity disorder, and schizophrenia/childhood-onset schizophrenia (COS). The number of patients reported to date is very limited, often lacking an extensive phenotypical and neuroradiological description of this ultra-rare syndrome. Here we report three subjects harboring UPF3B variants, presenting with variable clinical pictures, including cognitive impairment, central hypotonia, and syndromic features. Patients 1 and 2 harbored novel UPF3B variants-the p.(Lys207*) and p.(Asp429Serfs*27) ones, respectively-while the p.(Arg225Lysfs*229) variant, identified in Patient 3, was already reported in the literature. Novel features in our patients are represented by microcephaly, midface hypoplasia, and brain malformations. Then, we reviewed pertinent literature and compared previously reported subjects to our cases, providing possible insights into genotype-phenotype correlations in this emerging condition. Overall, the detailed phenotypic description of three patients carrying UPF3B variants is useful not only to expand the genotypic and phenotypic spectrum of UPF3B-related disorders, but also to ameliorate the clinical management of affected individuals.

The NHS Genomic Medicine service for England (GMS) was established in 2018 to "harness the power of genomic technology and science to improve the health of our population and deliver on the commitments in the NHS Long Term Plan". These commitments include being the first national health care system to offer WGS as part of routine care. The GMS comprises of 7 Genomic Laboratory Hubs (GLH) and associated Genomic Medicine Service Alliances (GMSAs). The GMSAs are working with health providers, patients and the public to embed genomics into mainstream healthcare and ensure easy and equitable access to the genomic investigations specified in the NHS Genomic Test Directory. There are approximately 50 NHS Mental Health Trusts in England which provide mental health services (including dementia, learning disability and autism services). The directory includes genetic tests relevant to the assessment of intellectual disability (ID) and dementia – for example microarray and the WGS neurodegeneration panel. There is little data on the use of genetic investigations within mental health services but what there is suggests overall low use with large variability in practice. A NTGMSA transformation project was commissioned to: map the utilisation of genomics investigations by NHS mental health trust in the North Thames (North London) region develop model "end to end" genomic testing pathways for adult ID services and dementia services. develop a strategy to increase genomic testing and improve equity of access Request data was extracted from the North Thames GLH (at Great Ormond Street hospital). Consultants in the Psychiatry of ID and psychiatrists working in dementia services in the North Thames region were surveyed about genomic testing. Model genomic testing pathways were developed using the "Clinical Pathway Initiative" framework (NHS Genomic Education Programme). Extensive consultation with stakeholders and in particular patient/carer groups was undertaken to create the pathways. Clinical nurse specialist posts have been created and QI projects set up to increase testing and address equity of access. 10 Mental Health Trust are covered by the NTGMSA footprint. It appears that genetic investigation of adults with ID is seldom initiated in mental health services with less than 10 requests over an 18 month period. We were unable to identify any requests for the dementia panel originating from Mental Health Trusts over the same period. Overall, the survey highlighted the need for further education/training about and support for genomic testing among the psychiatry workforce. Two model testing pathways have been developed. These can be adapted to fit the needs of individual services. The consultation process revealed broad support for the aims of the project. Services users and carers identified difficulties with the logistics of testing and lack of post diagnostic support as key areas for improvement. Mental and GMS clinicians and scientists highlighted the need for strong links between GMS and mental health services and the need for basic competencies in genomic medicine across the wider mental health workforce. The level of genetic testing in mental health services in North London is currently very low. People who meet criteria for genomic investigation (as laid out in the directory) should have easy and equitable access. It appears there is still much work to be done to support the workforce with the integration of genomic medicine in mental health settings.

Genetic alterations within the cAMP/PKA pathway result in a spectrum of adrenocortical disorders. Implicated genes include GNAS, PDE8, PDE11A, PRKAR1A/B, and PRKACA. To date, somatic PRKACA mutations and germline PRKACA copy number gain have been associated with the development of cortisol-secreting adrenocortical adenomas and bilateral adrenal hyperplasia, respectively. While perturbations within the PRKAR1A gene are known to cause Carney complex, PKRACA mutations are rarely associated with an extra-adrenal phenotype. We describe a mosaic PRKACA duplication in an infant who presented with a Carney-like complex at the age of three months with bilateral non-pigmented micronodular adrenal hyperplasia, severe early-onset Cushing syndrome, and distinct acral soft tissue overgrowth due to cutaneous mucinosis. This represents a novel manifestation of PRKACA disruption and broadens its extra-adrenal phenotype. It suggests that the Cushing syndrome phenotypes arising from somatic and germline PRKACA abnormalities likely exist on a spectrum. We emphasise the importance of ascertaining a genetic diagnosis for PRKACA-mediated disease.

A 6-month-old girl was referred for further management of her congenital malformations. These were identified antenatally, and, at birth, she was noted to have wrinkled abdominal skin (Figure 1) consistent with the syndrome of absent abdominal musculature (Eagle-Barrett syndrome). The typical appearance of the abdomen in these patients previously led to the descriptive term of "prune-belly syndrome." Additional malformations included an omphalocele and urologic abnormalities, including megacystis and a left megaureter.

Opitz G/BBB syndrome (OS) is a rare genetic developmental condition characterized by congenital defects along the midline of the body. The main clinical signs are represented by hypertelorism, laryngo–tracheo–esophageal defects and hypospadias. The X-linked form of the disease is associated with mutations in the MID1 gene located in Xp22 whereas mutations in the SPECC1L gene in 22q11 have been linked to few cases of the autosomal dominant form of this disorder, as well as to other genetic syndromes. In this study, we have undertaken a mutation screening of the SPECC1L gene in samples of sporadic OS cases in which mutations in the MID1 gene were excluded. The heterozygous missense variants identified are already reported in variant databases raising the issue of their pathogenetic meaning. Recently, it was reported that some clinical manifestations peculiar to OS signs are not observed in patients carrying mutations in the SPECC1L gene, leading to the proposal of the designation of ‘SPECC1L syndrome’ to refer to this disorder. Our study confirms that patients with diagnosis of OS, mainly characterized by the presence of hypospadias and laryngo–tracheo–esophageal defects, do not carry pathogenic SPECC1L mutations. In addition, SPECC1L syndrome-associated mutations are clustered in two specific domains of the protein, whereas the missense variants detected in our work lies elsewhere and the impact of these variants in the function of this protein is difficult to ascertain with the current knowledge and will require further investigations. Nonetheless, our study provides further insight into the SPECC1L syndrome classification.

BACKGROUND:Epilepsy is a main feature of Mowat Wilson Syndrome (MWS), a congenital malformation syndrome caused by ZEB2 variants. The aim of this study was to investigate the long-term evolution of the electroclinical phenotype of MWS in a large population. METHODS:Forty-individuals with a genetically confirmed diagnosis were enrolled. Three age groups were identified (t1 = 0-4; t2 = 5-12; t3 = >13 years); clinical data and EEG records were collected, analyzed, and compared for age group. Video-EEG recorded seizures were reviewed. RESULTS:Thirty-six of 40 individuals had epilepsy, of whom 35/35 aged >5 years. Almost all (35/36) presented focal seizures at onset (mean age at onset 3.4 ± 2.3 SD) that persisted, reduced in frequency, in 7/22 individuals after the age of 13. Absences occurred in 22/36 (mean age at onset 7.2 ± 0.9 SD); no one had absences before 6 and over 16 years old. Paroxysmal interictal abnormalities in sleep also followed an age-dependent evolution with a significant increase in frequency at school age (p = 0.002) and a reduction during adolescence (p = 0.008). Electrical Status Epilepticus during Sleep occurred in 14/36 (13/14 aged 5-13 years old at onset). Seven focal seizure ictal video-EEGs were collected: all were long-lasting and more visible clinical signs were often preceded by prolonged electrical and/or subtle (erratic head and eye orientation) seizures. Valproic acid was confirmed as the most widely used and effective drug, followed by levetiracetam. CONCLUSIONS:Epilepsy is a major sign of MWS with a characteristic, age-dependent, electroclinical pattern. Improvement with adolescence/adulthood is usually observed. Our data strengthen the hypothesis of a GABAergic transmission imbalance underlying ZEB2-related epilepsy.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.