Gene therapies are promising for diseases previously considered incurable. Adeno-associated virus serotype 9 (AAV9) demonstrates remarkable tropism for motor neurons (MNs) and represents an exciting candidate to target genetic causes of motor neuron diseases like amyotrophic lateral sclerosis (ALS). However, systemic delivery risks immunogenicity and off-target effects, therefore localised delivery to the CNS is advantageous. We assessed MN transduction in wild-type post-natal mice using AAV9-controlled, cytomegalovirus-promoter driven, enhanced GFP expression. Intra-cisterna magna (ICM) and intra-cerebroventricular (ICV) methods were compared. Four weeks post-delivery, GFP positivity in MN and astrocytes were quantified via immunohistochemical approaches and viral genome copy number determined by qPCR. All delivery methods achieved high MN transduction in lumbar spinal cord (> 68%). Unilateral ICV delivery provided the highest and most consistent levels (89 ± 3%), and minimal peripheral viral copies. ICV delivery resulted in higher astrocytic transduction, most notably in the cortex. Brainstem MN transduction was high with all methods (> 55%). We failed to find evidence of neuronal transduction in motor cortex. Viral genome copies trended higher in spinal cord and brainstem with ICV approaches, however further work is required to understand how bilateral repeated dose delivery leads to more profound increases. Whilst several routes of administration into cerebrospinal fluid exist, direct comparisons for targeting MNs in vivo remain limited. Overall, all methods of CNS-directed delivery result in high levels of motor neuron transduction in the lumbar spinal cord and brainstem, but not in motor cortex. Unilateral ICV appears to provide the best balance between consistent, high levels of transduction and low off-target effects. However, ICM might be the better option if seeking to avoid astrocytic transduction.

Abstract Context Recent genetic discoveries in congenital hyperinsulinism (HI) and advances in sequencing technology suggest that the diagnostic yield may be improved by rescreening in people with genetically unsolved HI. Objective To evaluate this hypothesis in a nationwide cohort of individuals with a historical diagnosis of HI of unknown genetic cause. Methods Twenty-seven probands, representing 77% of the genetically unsolved HI cases in Finland, underwent rescreening which targeted the coding regions of 18 known HI genes, and 5 relevant non-coding regions. The median age of the cohort was 21 years (range, 4–44 years). Participants had previously undergone a median of 3 genetic tests (range, 1–4), all of which yielded negative (n=17) or inconclusive (n=10) results. Results Genetic rescreening was informative in 22% (6 of 27) of cases. Definitive genetic diagnoses were established in 4 (15%) participants. These included the detection of non-coding variants in the ABCC8, HK1, and SLC16A1 genes, and a GCK mosaic variant (8% allele fraction). In 2 (7%) cases, revised genetic results but did not provide a definitive genetic diagnosis. Conclusions In this Finnish cohort, rescreening with a comprehensive gene panel provided new or revised diagnoses in 22% of cases, informing on medical management and recurrence risk. These findings emphasize the importance of regularly updating genetic testing strategies and highlight the clinical value of re-evaluating the need for rescreening in genetically unexplained HI cases even following clinical remission.

Rickets is a medical condition caused by vitamin D deficiency, typically caused by inadequate dietary intake, limited sun exposure, or, less commonly, genetic disorders. While skeletal abnormalities are the hallmark of rickets in children, oral manifestations, such as recurrent dental abscesses occurring in the absence of carious lesions, can also be observed. This report describes the case of a child presenting with oral features suggestive of hereditary rickets, despite the lack of skeletal abnormalities and without a confirmed genetic aetiology. Histological and microstructural analyses of dental tissues played a key role in guiding the diagnosis, ultimately leading to referral to a paediatrician and confirmation of vitamin D deficiency. A 4-year-old male presented to the Emergency Dental Department of a paediatric clinic with a history of spontaneous dental abscesses. Three affected primary teeth, extracted for clinical reasons, were comprehensively analysed using micro-computed tomography, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and optical microscopy. Investigations revealed an enlarged pulp chamber, pulpal calcifications, extensive interglobular dentine, and porous, hypomineralised enamel. Additionally, an irregular and poorly defined dentino-enamel junction was observed, along with abrupt spatial variations in mineral composition. The findings are consistent with defective biomineralisation. Subsequent biochemical testing confirmed vitamin D deficiency in the absence of a detectable genetic cause. The patient was supplemented with vitamin D and calcium, resulting in clinical improvement. Vitamin D deficiency profoundly impairs the development and mineralisation of dental hard tissues, including both enamel and dentine. These alterations compromise the structural integrity of teeth and may increase the risk of spontaneous dental abscesses. Early identification of such oral manifestations is critical for prompt diagnosis and appropriate management.

Medical providers and biogenetic messages about depression: A vignette experiment.

Generation of an induced pluripotent stem cell line (AHMUCNi004-A) from a 14-year-old male with Down syndrome.

Under the dual hit: genetic and phenotypic analysis of a Han family with severe adolescent cirrhosis from the convergence of Wilson's disease and favism.

Nephrolithiasis (NL) and nephrocalcinosis (NC) are common, recurrent conditions globally. While monogenic causes are increasingly recognized, data on their prevalence and spectrum remain limited in Saudi pediatric populations. This retrospective cross-sectional study was conducted in our tertiary care center from January 2008 to April 2023. Pediatric patients (0-18years) with radiologically confirmed NL/NC who underwent genetic testing were included. Clinical, biochemical, radiological, and genetic data were analyzed. Genetic variants were classified using ACMG criteria, and segregation analysis was performed when available. Of 186 pediatric patients diagnosed with NL/NC, 54 (29.03%) underwent genetic testing. Median age at diagnosis was 3months [IQR: 3-60], with median follow-up 56months [IQR: 24-108]. Genetic mutations related to NL/NC were identified in 35/54 patients (64.81%), most commonly in CLDN16 (28.57%), SLC2A2 (17.14%), AGXT (11.43%), and SLC12A1 (8.57%). Thirteen novel variants were identified, with eleven linked to NL/NC phenotypes. Eight patients (14.81%) developed kidney failure requiring kidney replacement therapy; CLDN16 was significantly associated with kidney failure and transplant (P = 0.003), and AGXT with liver transplant (P < 0.001). Notably, the MOCS1 gene was found in a patient with early-onset neurological symptoms, hypouricemia, and later confirmed NL/NC. Monogenic causes were identified in 35 of 54 (64.81%) Saudi pediatric patients with NL/NC who underwent genetic testing, a prevalence higher than reported internationally, likely due to the high consanguinity rate. Our findings underscore the importance of genetic testing in early-onset NL/NC. We recommend adding MOCS1 to the list of genes associated with monogenic NL/NC.

No evidence for the LRRK2 p.L1795F variant in a Southern Italian cohort with Parkinson's disease.

A 3-hit metabolic signaling model for the core symptoms of autism spectrum disorder.

Infertility represents a major public health concern, affecting approximately 15% of couples worldwide, with male factors contributing to more than half of all cases. Optimizing clinical management therefore necessitates a comprehensive understanding of the underlying pathophysiological mechanisms, not only to refine diagnostic stratification but also to advance therapeutic strategies—particularly in the context of medically assisted reproduction. Nevertheless, for a long time, no causal explanation was found in almost half of the cases of male infertility. This mainly concerns the most severe cases, where the available treatments remain ineffective. Scientists believed that in idiopathic infertility there are often underlying genetic causes. But the patients were under-explored and the genetic tests carried out were essentially limited to karyotype and old molecular biology techniques. Recently, the development and cost reduction of next-generation sequencing has enabled the identification of dozens of genes implicated in male infertility. This summary review of the literature reports the various chromosomal and gene abnormalities strongly correlated with syndromic and non-syndromic male infertility, depending on the level of impairment (central, primary testicular or post-testicular); and according to the nature of the abnormalities found in the spermogram – spermocytogram. Its results help to predict the chances of success of treatments and make it possible to better assess the potential risks to the health of the patient and his possible offspring in order to provide adequate genetic counseling.

Several diseases show geographic clustering, giving insights into possible genetic and environmental causes. The pathogenesis of Congenital Heart Disease (CHD) remains largely unknown and analysis of geographic distribution of CHD cases lacks input from large, national-scale datasets. People with structural CHD were selected from the Australia and New Zealand CHD Registry. Of people known to be still living, from linkage with the National Death Index, addresses were geocoded and aggregated to standardised geographic regions with measures of the Australian population. Areas were described based on measures of their remoteness and driving time to hospitals. The relationship between the distribution of the CHD and Australian populations was compared with bivariate spatial correlation. Of 81,349 people with structural CHD in the Registry, 63,863 were still living and could be geocoded. Overall, most people lived in Major Cities, and within 1-hour drive from a hospital, with the proportion the same across the CHD population, the "complex CHD" population and the Australian population. Across the country, there was a strong positive correlation between the Australian population and the CHD population. There were only a small number of areas (6%) where the Australian and the CHD populations were proportionally different. Overall, there was clear evidence that the geographic distribution of the CHD population proportionally follows the general Australian population. This suggests that there is unlikely to be any spatial clusters that are driven by genetic or environmental causes.

Variants in the keratin 6A (KRT6A) gene are a major cause of pachyonychia congenita (PC), a rare autosomal dominant disorder characterized by nail hypertrophy and other ectodermal abnormalities. This study aimed to identify the causative mutation in a PC family and investigate the underlying pathogenic mechanism. We performed exome sequencing on this PC pedigree and validated candidate variations using Sanger sequencing. In silico predictions and invitro experiments showed that the heterozygous missense variant c.512A>G in KRT6A was pathogenic, inducing protein aggregation and disrupting filamentous network structures. Enrichment analysis suggested that the PPAR signaling pathway played a crucial role in PC, with decreased expression of PPARβ/δ in HeLa cells. Comparative analysis of PC patients carrying the p.Asn171 variant revealed marked heterogeneity in clinical manifestations. Notably, oral leukokeratosis, a common phenotype in KRT6A mutation carriers, was not observed in the patients in this study. Interestingly, one patient presented with small papules around the lips and nasal bridge. We conclude that the c.512A>G variant in KRT6A is the genetic cause of this PC family, diagnosed as PC-K6a subtype. This study expands the phenotypic spectrum of congenital PC and suggests the PPAR signaling pathway as a potential therapeutic target.

Most infants born small for gestational age (SGA) experience catch-up growth within 2 years, while 10% to 15% remain short. The cause of this persistent growth failure remains unknown. To investigate the genetic causes of SGA with short stature (SGA-SS) due to failure of catch-up growth. A total of 191 children from multicenter SGA-SS cohorts across 7 hospitals in South Korea underwent whole-exome sequencing. Identified copy number variants (CNVs) were confirmed via chromosomal microarray analysis. Genetic variants were identified in 34 children (17.8% diagnostic rate). CNVs accounted for 50% (17/34), including 6 children with 22q11.2 microdeletion syndrome, predominantly exhibiting mild dysmorphic features without severe intellectual disability (ID), developmental delay (DD) or severe anomalies. Single-nucleotide variants (SNVs) were identified in 17 children (17/34, 50%). One had compound heterozygous mutations in SLC26A2, 1 likely pathogenic mutation, and another of uncertain significance. The remaining children had heterozygous variants, including 5 pathogenic variants in COL2A1, ACAN, SALL1, TAOK1, ANKRD11 and 11 likely pathogenic variants in PIK3R1, PLAG1, SCUBE3, COL9A2 (in 2 patients), SMAD4, PTPN11 (in 2 patients), CDKN1C, ACAN, NF1. A novel familial Silver-Russell syndrome case was linked to a CDKN1C mutation. Genetic causes were identified in 14 (58.3%) of 24 patients with ID/DD: 9 with CNVs and 5 with SNVs. SGA-SS has a heterogeneous genetic basis, with CNVs significantly contributing. The variable presentation of 22q11.2 microdeletion syndrome highlights its relevance. A genetic diagnosis is more likely in familial cases or those with ID/DD, supporting the utility of genetic testing.

Isolated dystonia generally occurs due to genetic causes, and the pattern and distribution may change over time. Botulinum toxin is the first-line treatment in those with isolated focal and segmental dystonia. We aimed to describe the clinical profile and evolution of adult patients with isolated focal and segmental dystonia presenting for treatment in our botulinum neurotoxin (BoNT) clinic, and the response to treatment, over 20 years. We retrospectively reviewed the medical records of patients with isolated focal and segmental dystonia who had at least two visits in our BoNT clinic. The clinical features at presentation and during follow-up, muscles injected for each type of dystonia, the self-reported benefit with BoNT, and adverse effects were analyzed. Five hundred seventy-eight patients with isolated dystonia were injected and had at least one additional follow-up. Five hundred seventeen (89.4%) had focal dystonia, and 61 (10.6%) had segmental dystonia. Cervical dystonia was the most common type. Spread to other regions was seen in 81 (14%) of patients. Those with blepharospasm as initial presentation tended to have the highest occurrence (27.3%) of spread to other parts. The mean response to BoNT was around 68%. The presence of a sensory trick and the absence of tremor were found to be predictors of good outcomes with BoNT. Isolated focal and segmental dystonia in adults has a good prognosis, with the majority responding well to BoNT and the dystonia remaining confined to the initially affected body part. Our study provides evidence for the response to BoNT therapy in a real-world scenario, outside of a clinical trial setting.

Increased neuronal activity restores circadian function in Drosophila models of C9orf72-ALS/FTD.

Retinitis pigmentosa (RP), affecting more than 20 million people worldwide, refers to a group of inherited retinal dystrophies characterized by progressive photoreceptor degeneration and vision loss. However, the underlying genetic causes of substantial RP cases remain unidentified. In this report, we identified a novel homozygous splicing variant, c.219-1delG, which introduced skipping of exon 4 of the ZNF124 gene in a large RP pedigree by whole-exome sequencing analysis. To elucidate the pathogenesis of the mutation, we generated a retina-specific knockout mouse model of ZNF124 murine homologous gene Gm20541, which manifested RP-like phenotypes characterized by reduced electroretinogram response and progressive retinal degeneration. Integrated analysis using CUT&Tag, ChIP-exo, and RNA-seq data further revealed that ZNF124 regulated MSX2 expression through binding its promoter region. Moreover, deletion of Msx2in the retina led to thinning of retina owing to progressive degeneration of rod cells. Integrated analysis of RNA-seq data from both Gm20541 and Msx2 mutant retinas indicated that ZNF124 is essential for maintaining normal retinal function by regulating Msx2 transcription, which in turn controls the expression of murine homologues of retinal dystrophy genes Rs1, Pde6g, and Pdc. Taken together, our study identified a novel mechanism of transcriptional regulation for retinal homeostasis via ZNF124-MSX2 axis and ZNF124 as a novel candidate gene for RP.

Bi-allelic variants in FSD1L cause a neurodevelopmental disorder overlapping with L1 syndrome.

Mutations in optineurin (OPTN) are linked to neurodegenerative diseases such as normal tension glaucoma (NTG) and amyotrophic lateral sclerosis. The E50K-OPTN mutation is the most common genetic cause of NTG, where it disrupts mitophagy and leads to the accumulation of dysfunctional mitochondria. To understand how cellular metabolism is altered in these persistent mitochondria, and whether any pathological state can be reversed, we investigated NTG-patient-derived fibroblasts carrying the E50K-OPTN mutation. We identified a form of mitochondrial leak metabolism driven by elevated levels of the ATP synthase c-subunit leak channel (ACLC). These cells exhibit reversed F1FO ATP synthase activity, increased mitochondrial proton leak, and fragmented mitochondria, resulting in inefficient oxidative phosphorylation and a shift toward aerobic glycolysis and high protein synthesis rate. The ratio of ATP synthase c-subunit to β-subunit was markedly elevated, suggesting open ACLC pores. Treatment with dexpramipexole normalized ATP synthase function and cellular metabolism, promoted ATP synthesis rather than hydrolysis and reduced protein synthesis rates. Dexpramipexole reduced p62 levels in E50K fibroblasts, consistent with a reduced mitophagic burden from decreased accumulation of damaged mitochondrial cargo. These findings identify ACLC-mediated leak as a central driver of metabolic dysfunction in E50K-OPTN glaucoma and suggest ACLC closure as a viable therapeutic strategy.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterised by the death of motor neurons leading to paralysis and death, generally 3-5 years post-symptom onset. The most frequent genetic cause of ALS is a hexanucleotide repeat expansion (HRE) in the chromosome 9 open reading frame 72 (C9orf72) gene, that has three major hypothesised pathological mechanisms including the production of dipeptide repeat proteins (DPRs). Our laboratory has previously identified purine metabolism dysfunction in induced neural progenitor cell-derived astrocytes (iAstrocytes) from C9orf72 ALS (C9-ALS) cases (C9-iAstrocytes), driven by loss of the enzyme adenosine deaminase (ADA). Here, we have demonstrated that loss of ADA along with changes to ecto-5'-nucleotidase and hypoxanthine-guanine phosphoribosyl transferase led to disruption in purine metabolite levels including purine dNTP output. These changes were recapitulated in patient CSF, whilst loss of ADA was recapitulated in patient white matter. Immunofluorescence also demonstrated purinosome formation dysfunction in C9-iAstrocytes. These changes are likely driven by DPRs as ADA loss was recapitulated in in vitro and in vivo DPR models. Finally, ADA levels could be recovered by reducing DPR levels either by inhibiting serine/arginine-rich splicing factor 1 or overexpressing RuvB-like 2. Our data demonstrate that DPR production negatively affects purine function in C9-ALS suggesting a potentially pivotal role for purine metabolism dysfunction in C9-ALS pathology.

Craniosynostosis (CS) is the second most common craniofacial birth defect after orofacial clefts. Genetic counseling is essential for reproductive planning in affected families. Nine fetal CS cases-six Apert syndrome (AS) and three Pfeiffer syndrome (PS)-with established genetic causes were retrospectively analyzed for clinical, radiological, and molecular features. Mean gestational age at first examination was 26.2weeks. Four AS and two PS cases were diagnosed during the prenatal stage by ultrasonography (USG), whereas two AS and one PS cases were identified during postmortem. Common prenatal findings included polyhydramnios, high flat forehead, and syndactyly. Two of the three cases diagnosed at the postmortem stage had multiple congenital anomalies (MCA), while in the third, CS was suspected due to frontal bossing and proptosis despite the absence of classic signs. All cases carried pathogenic FGFR2 variants. Proptosis, frontal bossing, and trigonocephaly are key prenatal indicators of CS, but their absence-especially with systemic anomalies-can challenge diagnosis. In cases with MCA, CS should be suspected even if classic signs are absent, particularly when syndactyly accompanies other complex abnormalities. Postmortem evaluation and molecular genetic testing are essential for definitive diagnosis, especially when clinical features are ambiguous.