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PubMed2026

Associations Between Antiparietal Cell Antibody Values and Atrophy in a South and Southeast Asian General Population.

GOALS: To investigate the association between atrophy severity and antiparietal cell antibody (APCA) levels in South and Southeast Asia. BACKGROUND: APCA is an autoantibody that damages gastric parietal cells; autoimmune gastritis (AIG) is a chronic gastric inflammatory disease related to APCA and severe predominant corpus atrophy. Although a positive APCA result is a key clinical diagnostic tool for AIG, its rates vary widely among ethnic groups, and its exact relationship with AIG and predominant corpus atrophy remains unclear. STUDY: Associations between histopathology-assessed and endoscopy-assessed atrophy, APCA positivity rates, Helicobacter pylori status, and pepsinogen levels were investigated in 1982 symptomatic patients from Vietnam, Thailand, Myanmar, Bangladesh, and Nepal. RESULTS: Overall, 38.5% of participants were negative for Helicobacter pylori infection, while 57.6% had a current infection. A positive APCA result, defined as a titer >10, was present in 44.0% of participants (95% confidence interval: 41.8%-46.3%, 873/1982). Pathologic atrophy, corpus atrophy, and predominant corpus atrophy were found in 8.7% (169/1982), 5.1% (101/1982), and 4.1% (81/1982) of participants, respectively. Positive APCA rates significantly differed among countries (10.6% to 63.8%, P <0.001). No significant correlation was found between APCA results and the presence or severity of atrophy. CONCLUSIONS: Although APCA positivity was high among symptomatic patients from South and Southeast Asian countries, few had severe predominant corpus atrophy or positive pepsinogen tests, which suggests a low rate of AIG in this population. Long-term surveillance of APCA-positive individuals is necessary to determine the clinical significance of a positive APCA result without AIG.

Humans↗

PubMed2022

Lipid hydroperoxides and oxylipins are mediators of denervation induced muscle atrophy.

Loss of innervation is a key driver of age associated muscle atrophy and weakness (sarcopenia). Our laboratory has previously shown that denervation induced atrophy is associated with the generation of mitochondrial hydroperoxides and lipid mediators produced downstream of cPLA2 and 12/15 lipoxygenase (12/15-LOX). To define the pathological impact of lipid hydroperoxides generated in denervation-induced atrophy in vivo, we treated mice with liproxstatin-1, a lipid hydroperoxide scavenger. We treated adult male mice with 5 mg/kg liproxstain-1 or vehicle one day prior to sciatic nerve transection and daily for 7 days post-denervation before tissue analysis. Liproxstatin-1 treatment protected gastrocnemius mass and fiber cross sectional area (∼40% less atrophy post-denervation in treated versus untreated mice). Mitochondrial hydroperoxide generation was reduced 80% in vitro and by over 65% in vivo by liproxstatin-1 treatment in denervated permeabilized muscle fibers and decreased the content of 4-HNE by ∼25% post-denervation. Lipidomic analysis revealed detectable levels of 25 oxylipins in denervated gastrocnemius muscle and significantly increased levels for eight oxylipins that are generated by metabolism of fatty acids through 12/15-LOX. Liproxstatin-1 treatment reduced the level of three of the eight denervation-induced oxylipins, specifically 15-HEPE, 13-HOTrE and 17-HDOHE. Denervation elevated protein degradation rates in muscle and treatment with liproxstatin-1 reduced rates of protein breakdown in denervated muscle. In contrast, protein synthesis rates were unchanged by denervation. Targeted proteomics revealed a number of proteins with altered expression after denervation but no effect of liproxstain-1. Transcriptomic analysis revealed 203 differentially expressed genes in denervated muscle from vehicle or liproxstatin-1 treated mice, including ER stress, nitric oxide signaling, Gαi signaling, glucocorticoid receptor signaling, and other pathways. Overall, these data suggest lipid hydroperoxides and oxylipins are key drivers of increased protein breakdown and muscle loss associated with denervation induced atrophy and a potential target for sarcopenia intervention.

Male↗

PubMed2026

The miR-206-3p/Cpeb1 axis delays acetylcholine receptor degradation and preserves neuromuscular junction stability in denervation-induced muscle atrophy.

Peripheral nerve injury leads to progressive neuromuscular junction (NMJ) destabilization and acetylcholine receptor (AChR) degradation, which are critical drivers of denervation-induced muscle atrophy and impaired motor recovery. However, the post-transcriptional mechanisms regulating AChR stability during denervation remain poorly understood. Here, we investigated the role of miR-206-3p in NMJ maintenance and muscle preservation after denervation, with a focus on its interaction with the RNA-binding protein cytoplasmic polyadenylation element binding protein 1 (Cpeb1). Using C2C12 myoblasts and a sciatic nerve transection mouse model, we demonstrate that miR-206-3p promotes myogenic differentiation, enhances AChR clustering, and preserves postsynaptic AChR morphology. miR-206-3p directly targets the 3' untranslated region of Cpeb1, suppressing its expression, as confirmed by dual-luciferase reporter assays. In vivo, adeno-associated virus-mediated overexpression of miR-206-3p delayed denervation-induced AChR fragmentation, attenuated muscle atrophy, and significantly improved motor function recovery. Conversely, Cpeb1 overexpression accelerated AChR degradation and muscle wasting, whereas co-overexpression of miR-206-3p mitigated these detrimental effects, indicating that Cpeb1 is a key downstream effector of miR-206-3p. Collectively, our findings identify the miR-206-3p/Cpeb1 axis as a previously unrecognized regulator of NMJ stability and muscle integrity after denervation, providing mechanistic insight and a potential therapeutic target for preserving neuromuscular function during prolonged denervation.

Animals↗

PubMed2024

Concomitant telomere attrition is associated with spinal muscular atrophy in highly inbred region of North India: unraveling the thread in Kashmir region.

Spinal muscular atrophy (SMA) is a rare genetic disorder that unequivocally results in the degeneration of motor neurons, leading to muscle weakness and atrophy. This condition is caused by a mutation in the survival motor neuron 1 (SMN1) gene, which inevitably results in a deficiency of the SMN protein. In present study, we investigated the potential role of telomere attrition in SMA patients. Relative telomere length in peripheral blood lymphocytes was measured by Monochrome Multiplex Quantitative Polymerase Chain Reaction (MMQPCR) in 98 subjects and we conclusively found that SMA cases exhibit telomere attrition compared to healthy controls (P = 4 × 10- 2). Moreover, significant attrition was also observed in severe form of SMA, i.e. SMA type 0 (P = 0.04) as well.Although, the exact mechanism through which telomere shortening contributes to the pathogenesis of SMA is not fully understood and is yet to be delineated. However, one possibility is that telomere shortening leads to genomic instability and DNA damage, which can contribute to motor neuron degeneration. Another possibility is that telomere shortening leads to cellular senescence, which can impair the ability of motor neurons to regenerate and repair themselves. Recent studies have suggested that telomere shortening may be a potential therapeutic target in SMA. Thus, understanding the role of SMN1 gene in disease pathogenesis & its effect on telomere length will aid in estimating the risk & prognosis of SMA in genetically less explored & highly inbred region of Kashmir, Northern India.

Humans↗

PubMed2026

C9orf72-associated poly-GR in skeletal muscle leads to neuromuscular junction deficits and muscle atrophy.

Hexanucleotide repeat expansions in C9orf72 produce dipeptide repeat (DPR) proteins that are widely expressed, including in the nervous system and skeletal muscle. Among these DPRs, arginine-containing proteins, poly-GR and poly-PR, are toxic in the nervous system, but whether DPRs in skeletal muscle contribute to amyotrophic lateral sclerosis (ALS) pathogenesis is unclear. Here, we show that muscle-restricted expression of poly-GR drives motor deficits in mice, including muscle atrophy and neuromuscular junction (NMJ) deficits. Poly-GR in muscle interacted with the NMJ key organizer MuSK and promoted MuSK degradation, disrupting postsynaptic structure and impairing neuromuscular transmission. Importantly, a MuSK agonist antibody (X-17) stabilized NMJs and rescued neuromuscular transmission. Moreover, poly-GR in muscle activated the integrated stress response (ISR), elevating eIF2α phosphorylation and broadly suppressing protein translation. ISR inhibition with ISRIB restored translation and MuSK protein levels and ameliorated both muscle atrophy and NMJ deficits. These findings demonstrate that skeletal muscle actively contributes to C9orf72-ALS pathology. Targeting muscle with ISRIB offers a therapeutic strategy to preserve motor function in C9orf72-ALS.

Animals↗

PubMed2025

Marek's disease virus-1 unique gene LORF1 is involved in viral replication and MDV-1/Md5-induced atrophy of the bursa of Fabricius.

Marek's disease virus (MDV), an alphaherpesvirus, causes severe immunosuppression and T cell lymphomas in chickens, known as Marek's disease (MD), an economically important poultry disease primarily controlled by vaccination. Importantly, it also serves as a comparative model for studying herpesvirus-induced tumor formation in humans. MDV encodes more than 100 genes, most of which have unknown functions. MDV LORF1 is unique to serotype I MDV (MDV-1), lacking homologs in other herpesviruses, and has not been explored yet. To this end, an infectious bacterial artificial chromosome (BAC) harboring the complete genome of the MDV-1 very virulent strain Md5 was generated, and the rescued rMd5 maintained biological properties similar to the parental virus both in vitro and in vivo. Subsequently, rMd5ΔLORF1, a recombinant Md5 virus deficient in pLORF1 expression, was generated by a frameshift mutation in the LORF1 gene. Chickens infected with rMd5ΔLORF1 exhibited a lower mortality rate and delayed bursal atrophy than those infected with the parental rMd5 and the revertant virus (rMd5-reLORF1). Consistently, viral loads of rMd5ΔLORF1 were obviously lower than those of rMd5 or rMd5-reLORF1 in the bursa, but not in the spleen. Importantly, we found that pLORF1 deficiency impairs viral replication in bursal B cells. Furthermore, we showed that pLORF1 associated with the cellular membrane, interacted with MDV structural proteins, and exhibited punctate colocalization with tegument or capsid proteins in the cytoplasm. Taken together, this study demonstrates for the first time that the MDV-1 unique gene LORF1 is involved in MDV-induced bursal atrophy but not in tumor formation.

Animals↗

PubMed2026

Compound muscle action potential amplitudes in newborn screen positive spinal muscular atrophy.

OBJECTIVE: To evaluate the utility of compound muscle action potential (CMAP) amplitudes as biomarkers of disease severity in newborn screening (NBS)-positive infants with spinal muscular atrophy (SMA). METHODS: We conducted a retrospective review of 21 infants identified through SMA NBS (11 with 2 SMN2 copies and 10 with 3 SMN2 copies). Baseline and serial right median, ulnar, and fibular motor nerve CMAP amplitudes (millivolts, mV) were obtained during the study. Functional outcomes were assessed using the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND). RESULTS: At baseline, infants with 2 SMN2 copies demonstrated significantly lower median, ulnar, and fibular CMAP amplitudes compared with infants with 3 SMN2 copies (p < 0.05). In contrast, baseline CHOP-INTEND scores did not differ significantly between the two groups. Prior to genetic confirmation, a right median CMAP amplitude ≥3.2 mV predicted ≥3 SMN2 copies. Following treatment, right median and fibular CMAP amplitudes demonstrated significant improvement over time, including in analyses accounting for SMN2 copies number. CONCLUSION: CMAP amplitudes obtained from multiple upper- and lower-extremity motor nerves provided objective electrophysiological measures that distinguished infants with two versus three SMN2 copies, despite similar baseline CHOP-INTEND scores. Furthermore, CMAP abnormalities were detectable in some cases before confirmatory genetic testing results became available. Serial CMAP measurements demonstrated significant longitudinal changes following treatment, whereas functional assessments approached ceiling values, supporting the potential value of electrophysiological monitoring in the era of disease-modifying therapies. SIGNIFICANCE: CMAP assessment is a useful adjunct in the evaluation of infants identified through SMA NBS.

Humans↗

PubMed2026

A novel ASCC1 splice-site variant broadens the phenotypic spectrum of spinal muscular atrophy with congenital bone fractures type 2.

Spinal muscular atrophy with congenital bone fractures type 2 (SMABF2) is an ultra-rare neuromuscular disorder caused by pathogenic variants affecting the ASC-1 complex, most commonly ASCC1. The disorder is typically characterized by severe congenital hypotonia, prenatal or congenital fractures, and early respiratory failure. We report a girl with a novel homozygous intronic donor-site variant, c.95+5G>C, in ASCC1. In contrast to the classic SMABF2 phenotype, she had no congenital fractures and survived until 7 years of age. Her clinical presentation included generalized hypotonia, areflexia, minimal spontaneous movements, dysmorphic features related to fetal hypomobility, progressive respiratory insufficiency requiring tracheostomy and gastrostomy, and cardiac involvement. This case expands both the genetic and phenotypic spectrum of ASCC1-associated disease. The comparatively prolonged survival and absence of congenital fractures suggest that not all ASCC1 variants result in a fully loss-of-function phenotype. However, this interpretation remains hypothetical because functional RNA studies were not performed.

Humans↗

PubMed2024

Diagnosing missed cases of spinal muscular atrophy in genome, exome, and panel sequencing data sets.

PURPOSE: We set out to develop a publicly available tool that could accurately diagnose spinal muscular atrophy (SMA) in exome, genome, or panel sequencing data sets aligned to a GRCh37, GRCh38, or T2T reference genome. METHODS: The SMA Finder algorithm detects the most common genetic causes of SMA by evaluating reads that overlap the c.840 position of the SMN1 and SMN2 paralogs. It uses these reads to determine whether an individual most likely has 0 functional copies of SMN1. RESULTS: We developed SMA Finder and evaluated it on 16,626 exomes and 3911 genomes from the Broad Institute Center for Mendelian Genomics, 1157 exomes and 8762 panel samples from Tartu University Hospital, and 198,868 exomes and 198,868 genomes from the UK Biobank. SMA Finder's false-positive rate was below 1 in 200,000 samples, its positive predictive value was greater than 96%, and its true-positive rate was 29 out of 29. Most of these SMA diagnoses had initially been clinically misdiagnosed as limb-girdle muscular dystrophy. CONCLUSION: Our extensive evaluation of SMA Finder on exome, genome, and panel sequencing samples found it to have nearly 100% accuracy and demonstrated its ability to reduce diagnostic delays, particularly in individuals with milder subtypes of SMA. Given this accuracy, the common misdiagnoses identified here, the widespread availability of clinical confirmatory testing for SMA, and the existence of treatment options, we propose that it is time to add SMN1 to the American College of Medical Genetics list of genes with reportable secondary findings after genome and exome sequencing.

Humans↗

PubMed2025

Biallelic null variants in C19orf44 cause a unique late-onset retinal dystrophy phenotype characterized by patchy perifoveal chorioretinal atrophy.

PURPOSE: To identify the genetic cause for disease in individuals affected with inherited retinal disease and to characterize their retinal phenotype and the properties of the underlying gene. METHODS: Participants underwent a comprehensive ophthalmological evaluation, including best-corrected visual acuity, visual field testing, fundus autofluorescence, optical coherence tomography, and electroretinography. Genetic analyses included exome, genome, and Sanger sequencing. Gene expression pattern was analyzed by reverse transcription-polymerase chain reaction. Localization of the encoded protein in cells and in the human retina was examined by immunofluorescence staining. RESULTS: Four different pathogenic variants in C19orf44 were identified in 15 biallelic individuals from 11 unrelated families. The most common variant was c.549_550del p.(Ser185ProfsTer2). Most individuals were affected with a unique clinical phenotype characterized by late-onset patchy perifoveal chorioretinal atrophy and electroretinographic features of rod-cone degeneration. C19orf44 is expressed in various human tissues, including the retina, where it was found in the outer nuclear layer and in the outer plexiform layer. In cultured cells (hTERT RPE-1 and HeLa) and in human primary fibroblasts, C19orf44 is found in the nucleus, and it is downregulated during mitosis. CONCLUSION: Based on our results, C19orf44 is crucial for normal human retinal function, and pathogenic variants in this gene are associated with autosomal recessive inherited retinal disease.

Humans↗

PubMed2026

Plasma cfDNA hypermethylation at SNCA intron 1 as a potential blood-based epigenetic signal in Parkinson's disease and multiple system atrophy.

BACKGROUND: The accumulation of α-synuclein (SNCA) in the central nervous system is a hallmark of Parkinson's disease (PD) and multiple system atrophy (MSA). SNCA intron 1 methylation is implicated in SNCA transcriptional regulation and may serve as a peripheral epigenetic signal in synucleinopathies. However, studies of SNCA methylation in leukocyte-derived DNA have yielded inconsistent results. We aimed to evaluate whether cell-free DNA (cfDNA)-based SNCA intron 1 methylation differs in PD or MSA compared with normal controls (NC). METHODS: Plasma cfDNA was collected from 105 patients with PD, 50 with MSA, and 114 NC. DNA methylation at CpG sites 10-17 was quantified by bisulfite pyrosequencing. Multivariable linear and logistic regression models, adjusted for age, sex, and education, were used to compare methylation levels and estimate odds ratios (ORs). RESULTS: Patients with PD exhibited hypermethylation at CpG site 14 and higher mean methylation across CpG sites 10-17 compared with NC. Patients with MSA showed hypermethylation at CpG sites 10, 12, 13, and 17 and elevated mean methylation. Elevated mean methylation was also observed in drug-naïve de novo PD and early-stage PD patients. Compared with the lowest tertile, the highest mean methylation tertile was associated with increased odds of PD (OR, 2.49; 95% CI, 1.08-5.92) and MSA (OR, 5.02; 95% CI, 1.58-18.00). CONCLUSION: Plasma cfDNA SNCA intron 1 hypermethylation is associated with PD and MSA and detectable in drug-naïve and early-stage PD. It may represent a peripheral epigenetic alteration and warrants evaluation as an adjunctive signal for early screening.

Humans↗

PubMed2026

Chromosome X-wide association study in multiple system atrophy identifies sex-differential risk loci.

The human X chromosome accounts for ∼5% of the genome. Despite its size, the role of X-chromosomal variants in human diseases is not well understood, mainly due to its distinct inheritance pattern and the frequent omission of sex chromosomes from genome-wide association studies. This study used whole-genome sequencing data from 888 multiple system atrophy (MSA) cases and 7128 controls to perform an X-chromosome-wide common variant association study. Our analyses revealed two sex-differential risk loci: one located at Xq28, associated with increased risk for MSA in females [index variant: rs4898389, odds ratio (OR) = 1.69, 95% confidence interval (CI) = 1.40-2.03, P-value = 2.43 × 10⁻⁸], and another at Xp22.2 within the TBL1X gene, identified in males (index variant: rs6638956, OR = 1.48, 95%CI = 1.26-1.73, P-value = 9.92 × 10⁻⁷). In the Xq28 locus, colocalization analyses pointed to FAM3A and PLXNA3 as genes of interest. These findings emphasize the vital role of sex-differential genetic factors in the pathogenesis of MSA.

Humans↗

PubMed2026

Multi-Omics Landscape of Paraspinal Muscles in Spinal Muscular Atrophy With Scoliosis.

Most spinal muscular atrophy (SMA) patients develop severe scoliosis by late adolescence. Given that the paraspinal muscles-particularly the multifidus-are indispensable for maintaining spinal stability, their site-specific multi-omics characteristics in SMA remain insufficiently defined. Herein, integrated multi-omics sequencing was performed on bilateral multifidus samples from SMA patients and surgical controls. We identified 5219 differentially expressed genes, 1063 differentially expressed proteins and 370 differential metabolites between the control and SMA, showing significant enrichment in glucose and amino acid metabolism pathways, specifically key steps of glycolysis/gluconeogenesis. Key enzymes in the glycolytic process such as PFKM, ENO3 and PKM1 were markedly downregulated. Notably, a comparative analysis of the bilateral paraspinal muscles in SMA revealed asymmetrical metabolic signatures in carbohydrate and amino acid processing between the concave and convex sides. Key regulatory enzymes exhibited significant differential expression: PYGL, a central driver of starch and sucrose metabolism; creatine kinase, involved in arginine and proline metabolism; and PGAM2, a key mediator of glycine, serine, and threonine metabolism. These metabolic signatures indicate a complex metabolic reprogramming in the multifidus, where asymmetric disparities point to the influence of mechanical loading, while systemic dysregulation aligns with the effects of SMN depletion.

Humans↗

PubMed2026

Characteristics of early-onset, rapidly progressive scoliosis in spinal muscular atrophy type I treated with disease-modifying therapy -a multicenter retrospective study conducted in Japan.

In the era of disease-modifying therapy (DMT), almost all patients with spinal muscular atrophy (SMA) type I treated after onset, but before 6 months of age, develop early-onset, rapidly progressive scoliosis by 2 years of age, despite improvements in their motor function. Seven symptomatic patients with SMA type I who were treated before the age of 6 months were included in this retrospective observational study. Scoliosis had developed in all patients by 27 months of age. Among them, the patients who could stand with support or independently (standing patients; n = 3) tended to present with more progressive scoliosis than the sitters (n = 4). All standing patients demonstrated thoracic hyperkyphosis before or at the time of their scoliosis diagnosis. Despite receiving DMT, these patients continued to show residual key manifestations of SMA type I. Chronic difficulty maintaining posture due to trunk muscle weakness in the lying, sitting, or standing position was considered to be the main contributor to the development and progression of the scoliosis. The development and progression of such scoliosis, which begins in infancy, may be related to inappropriate postural management, which is not currently recognized as such by clinicians, caregivers, or guardians. In this population, it is important to closely monitor patients for such scoliosis from soon after the diagnosis of SMA. As this type of scoliosis progresses rapidly during the early developmental stage, when surgery is not possible, it is necessary to establish a proactive non-surgical management strategy for it.

Humans↗

PubMed2026

Clinical and Genetic Spectrum of ACO2-Linked Dominant Optic Atrophy.

IMPORTANCE: Aconitase 2 (ACO2) gene variants are one of the most frequent causes of dominant optic atrophy (DOA). However, the associated phenotypes and genotypes still lack proper characterization. OBJECTIVE: To characterize the clinical and genetic spectrum of ACO2-related DOA and evaluate genotype-phenotype correlations. DESIGN, SETTING, AND PARTICIPANTS: This was a retrospective case series to describe the ophthalmological examination of novel DOA cases with a heterozygous ACO2 variant. Data were collected from 13 reference centers in ophthalmology from France and Great Britain between January 2021 and September 2025. Included participants were those patients with OA and confirmed heterozygous or compound heterozygous ACO2 variants. EXPOSURES: DOA cases with a heterozygous ACO2 variant. MAIN OUTCOMES AND MEASURES: Positive molecular diagnosis for ACO2 variants by next-generation sequencing, clinical examination including age at diagnosis, sex, best-corrected visual acuity (BCVA), retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) thickness, visual field mean deviation (MD), and fundus examination. RESULTS: Data for 55 patients (median [IQR] age at diagnosis for 45 patients, 24 [8-51] years; 33 male [67%]) from 37 families with ACO2 variants were compiled. Analyses were conducted on 49 patients who were strictly heterozygous or compound heterozygous with the c.220C>G benign variant. Clinical data disclosed a high variability of severity, from pauci-symptomatic up to legal blindness. Median BCVA was 0.46 logMAR (Snellen equivalent, 20/63; IQR 0.00-0.89; n = 45). Four patients exhibited retinal abnormalities: 3 displayed a foveopathy, and 1 had retinitis pigmentosa. There were 12 previously unreported variants (to the authors' knowledge), including the deletion of ACO2 exon 9. No correlation between BCVA and sex, age at diagnosis (Spearman ρ = -0.19; 95% CI, -0.45 to 0.07), or variant type (Kruskal-Wallis test P =.33) was found, but there was a correlation between BCVA and RNFL (Spearman ρ = -0.74; 95% CI, -0.85 to -0.54), GCL (Spearman ρ = -0.60; 95% CI, -0.79 to -0.30), and MD (Spearman ρ = -0.65; 95% CI, -0.89 to -0.31). RNFL correlated with GCL (Spearman ρ = 0.69; 95% CI, 0.42-0.87) and MD (Spearman ρ = 0.57; 95% CI, 0.14-0.85); age at diagnosis correlated with GCL (Spearman ρ = -0.37; 95% CI, -0.63 to -0.03). CONCLUSIONS AND RELEVANCE: Results of this case series reveal the high clinical heterogeneity among patients with ACO2-related DOA and demonstrated that some of these patients can also exhibit retinal abnormalities. In addition, there was a deletion of an entire ACO2 exon, emphasizing the potential importance of searching for large genomic rearrangements in patients without a molecular diagnosis. These findings support further studies to explain clinical variability, as no genotype-phenotype correlation was encountered.

Humans↗

PubMed2026

Genetic evidence that advanced COVID-19 accelerates longitudinal brain atrophy: A Mendelian randomization study.

Coronavirus disease 2019 (COVID-19) was reported to persist long-term in the brain and leave several long-term neurologic sequelae. However, the causal relationship between COVID-19 and brain aging is still unknown. The genome-wide association study (GWAS) data on COVID-19 phenotypes (susceptibility, hospitalization, and severity), involving a total of 5,779,391 participants, were collected from the COVID-19 Host Genetics Initiative. In addition, GWAS data on longitudinal changes in 15 brain structures, assessed via magnetic resonance imaging across the lifespan, were sourced from the ENIGMA Consortium and involved 15,640 participants. Two-sample Mendelian randomization was conducted to infer the causal relationship between COVID-19 and longitudinal brain changes. Multi-trait GWAS meta-analysis, colocalization, and fine-mapping analyses were performed to identify shared genetic etiologies. H3K27me3 ChIP-seq was used to evaluate the regulatory effect of colocalized loci. Two-step Mendelian randomization was applied to explore potential mediating mechanisms across multi-omics layers, including proteomics, metabolomics, and immunomics. Our results showed that COVID-19 hospitalization (β = -262.405, P = .041) and severity (β = -177.676, P = .049) were genetically associated with atrophied volume of total brain during longitudinal change. This suggests that individuals with advanced COVID-19 may be more susceptible to accelerated global brain aging. Caudate was genetically affected by all COVID-19 phenotypes. Seven variants were shared between advanced COVID-19 and global brain aging. rs117169628 was colocalized between advanced COVID-19 and global brain aging, and exerted an inhibitory effect on CDH15 expression, further strengthening the causality. Six metabolites, 1 protein, and 1 immune trait were identified as potential mediators. Our study indicates that advanced COVID-19 might be genetically associated with accelerated brain aging. Brain health should be paid more attention in long COVID-19.

Humans↗

PubMed2026

A New Case of Lethal Congenital Contracture Syndrome Type 3 With Hyperinsulinism and Optic Atrophy.

Lethal congenital contracture syndrome 3 (LCCS3, MIM #611369) is a rare autosomal recessive neuromuscular disorder caused by biallelic loss-of-function (LOF) variants in PIP5K1C, reported in only two families to date. It typically presents with severe fetal akinesia, arthrogryposis multiplex congenita, and perinatal lethality due to respiratory insufficiency case. Herein, we report a new case with survival beyond birth. Prenatal findings included clubfeet with preserved amniotic fluid volume and fetal movements. The infant was delivered by cesarean section at 37 + 7 weeks following breech presentation and developed respiratory distress requiring 14 days of ventilatory support. Physical examination revealed bilateral talipes equinovarus, flexion contractures of the knees, restricted hip mobility, clenched hands with flexion contractures of the third and fourth fingers, and hyperextension of the second and fifth fingers. Neurologically, he had encephalopathy, profound hypotonia with a frog posture, and abnormal neonatal reflexes with a discontinuous background pattern on cerebral function monitoring. Additional observed features were bilateral optic atrophy and hyperinsulinemic hypoglycemia responsive to Diazoxide. Trio genome sequencing identified a homozygous pathogenic splice-site variant in PIP5K1C (c.1127+1G>A, NM_012398.3). The infant died at 6 months from multisystemic failure. Further studies are warranted to elucidate the pathomechanisms underlying the PIP5K1C defect and its phenotypic consequences.

LCCS3↗

PubMed2026

Plasma von Willebrand Factor and ADAMTS13 Interact With APOE-ε4 in Predicting Longitudinal Brain Atrophy and Cognitive Decline Over a 9-Year Follow-Up.

BACKGROUND: Von Willebrand factor (VWF) and ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motif, 13) are linked to dementia risk, and limited evidence suggests apolipoprotein E (APOE)-ε4 alters VWF release. This study assessed whether baseline VWF and ADAMTS13 levels predict neurodegeneration and cognitive decline and evaluated effect modification by APOE-ε4 carriership. METHODS: Vanderbilt Memory and Aging Project cohort participants (n=332, 73±7 years, 59% male) completed serial blood draw, neuropsychological assessment, and brain magnetic resonance imaging over 6.4 years (range 1.4-9.7 years). Baseline plasma VWF and ADAMTS13 levels were quantified using mass spectrometry and Olink. Fully adjusted linear mixed-effects models related protein×time and protein×APOE-ε4×time interaction terms to longitudinal brain magnetic resonance imaging and neuropsychological outcomes. RESULTS: Lower baseline ADAMTS13 predicted faster declines in language (β=0.11, P=0.01), information processing speed (β=0.27, P=0.001), executive function (β=0.01, P=0.03), episodic memory (β=0.01, P=0.03), and visuospatial ability (β=0.11, P=0.001) and faster increases in global (β=-0.29, P=0.01) and frontal (β=-0.17, P=0.01) white matter hyperintensity volumes. Associations between ADAMTS13 and faster rates of cognitive decline and white matter injury were driven by APOE-ε4 carriers. Models relating VWF to longitudinal outcomes were null. APOE-ε4 interacted with VWF on longitudinal gray matter volumetric outcomes, such that faster rates of global gray matter atrophy were observed with higher baseline VWF levels among APOE-ε4 noncarriers only (β=-1530.5, P<0.001). CONCLUSIONS: ADAMTS13 shows promise as a potential plasma biomarker for brain aging outcomes, but additional research is warranted to understand the performance of VWF in the presence versus absence of an APOE-ε4 allele.

Humans↗