NEUROGENETICS

Introducing a novel TRAPPC10 gene variant as a potential cause of developmental delay and intellectual disability in an Iranian family
Nozari A, Babaahmadi P, Jalilian N, Sadeghi T and Hasani M
TRAPP complexes are crucial components for intracellular transport and cellular organization. Their role in vesicle trafficking, particularly through their involvement in the secretory pathway, make them more important in neurodevelopmental mechanisms. This study aims to identify a novel genetic variant, associated with developmental delay and intellectual disability by analyzing a consanguineous Iranian family.
DHDDS-related epilepsy with hippocampal atrophy: a case report
de Oliveira Franco Á, Morillos MB, Bravo Leite MT, Bianchin MM and Torres CM
Developmental delay and seizures with or without movement abnormalities (DEDSM) is a neurodevelopmental phenotype associated with monoallelic mutations in the DHDDS gene. We report a novel case of DEDSM linked to a DHDDS variant (c.614G > A, p.Arg205Gln) in a 45-year-old Brazilian patient presenting with refractory epilepsy, ataxia, dystonia, parkinsonism, and global developmental delay. This is the first case to associate a DHDDS variant with hippocampal atrophy on neuroimaging. After adjustments in anticonvulsant therapy, seizure control was achieved, and the patient-who was previously unable to walk due to frequent falls attributed to myoclonic jerks-showed significant improvement in gait and mobility.
Dystrophinopathy patient data as a guide to interpretation of pregestational female population screening for DMD gene variants
Sagi-Dain L, Aartsma-Rus A, Echar M, Grinshpun-Cohen J and Singer A
Pregestational population screening of healthy females for copy number variants in DMD gene has raised numerous challenges regarding the interpretation and disclosure of these findings. Our objective was to analyze data from a local dystrophinopathy patient database, in comparison to population screening results. Utilizing the "Little steps" association registry for children with dystrophinopathy, we classified genetic findings (out-of-frame, in-frame, or difficult-to-predict) in 231 DMD and 90 BMD male patients. A comparison was made with a previously published cohort of 162 female carriers identified through population screening. Duplications classified as "difficult to predict" were absent in DMD/BMD patients, as opposed to 45.1% of women analyzed in the scope of population screening (p < 0.0001). While the distribution of deletions did not differ between the groups, significantly higher proportion of duplications initiated at the proximal hot spot in the DMD/BMD cohort (87.1%), vs. only 11.7% in women analyzed through population screening (p = 0.0038). Notably, duplications initiating in the dp427c promoter area were noted only in the latter cohort (n = 62). Local databases of dystrophinopathy patients can facilitate analysis and reporting of pregestational female population screening results. These conclusions facilitate future introductions of population screening genetic tests for diseases with variable presentation.
Expansion of phenotypic and genotypic data in autism spectrum disorders due to variants in the CHD8 gene
Parfenenko MA, Dantsev IS, Bochenkov SV, Kuramagomedova RG, Vinogradova NV, Afanaseva MP, Groznova OS and Voinova VI
Autism spectrum disorders are a group of the most common disorders of neuropsychiatric development, characterized by difficulties in social interaction and adherence to stereotypic behavioral patterns. This group of conditions frequently co-occurs with intellectual disability, epilepsy, attention-deficit hyperactivity disorder, connective tissue disorders and others. Among the most common molecular-genetic causes of autism spectrum disorders are pathogenic variants in the CHD8 gene. CHD8 codes for chromodomain-helicase-DNA-binding protein 8 - a chromatin remodeler that regulates cellular proliferation and brain development in embryogenesis. 6 children and 1 adult (mother of 1 of the children) and were found to have clinically significant variants in CHD8 on whole genome sequencing (3 children and 1 adult had likely pathogenic variants, 3 children- variants of unknown significance). Their phenotype consisted of autism spectrum disorders, developmental delay, ataxia, overgrowth and other signs typically observed in patients with pathogenic variants in CHD8, as well as common comorbidities of autism spectrum disorders, such as attention-deficit hyperactivity disorder and connective tissue disorders. Additionally, 4 patients had hepatomegaly and 2- hyperbilirubinemia (1 had both) - clinical features have not been previously associated with pathogenic variants in CHD8. 2 patients also presented with cardiovascular abnormalities, primarily arrythmias and, in 1 case, cardiomyopathy- also uncharacteristic of patients with pathogenic variants in CHD8. Further research is required to determine the mechanisms underlying the abovementioned clinical features, which are likely carried out through complex interactions between CHD8 and other regulatory proteins.
TREK-1 channel as a therapeutic target for dexmedetomidine-mediated neuroprotection in cerebral ischemia
Xu Y, Teng X, Wei M and Liu Y
Our objective is to explore the protective effect of Dexmedetomidine on brain apoptosis and its mechanism through TREK-1 pathway. Forty male Sprague-Dawley rats were allocated into four groups: Sham, Cerebral Ischemia/Reperfusion Injury (CIRI), 50 µg/kg Dex, and 100 µg/kg Dex. A rat model of middle cerebral artery occlusion (MCAO) was employed to simulate cerebral embolism. Primary cortical neurons were exposed to Dex for 48 h, with some receiving additional treatment with 100 µM yohimbine hydrochloride (YOH) or TREK-1 small interfering RNA (siRNA). Neuronal damage was assessed using hematoxylin and eosin (HE) staining. Cell viability and apoptosis were measured by Cell Counting Kit-8 (CCK8) and flow cytometry, respectively. Protein and gene expression levels of Bcl-2, Bax, and TREK-1 were determined by Western blot and real-time polymerase chain reaction (PCR). Histopathological changes revealed that Dex treatment at both 50 µg/kg and 100 µg/kg significantly mitigated neuronal damage compared to the CIRI group. YOH treatment and Trek1 siRNA significantly reduced cell viability (p < 0.05). The mRNA expression and protein levels of TREK-1 and Bax were remarkably increased, while mRNA expression and protein levels of Bcl-2 was seriously decreased after CIRI modeling. In contrast, Dex treatment at both concentrations led to decreased TREK-1 and Bax expression and increased Bcl-2 expression in primary cortical neurons. Addition of 100 µM YOH and Trek1 siRNA reversed the effects of Dex on apoptosis-related genes (p < 0.05). Dex exerts neuroprotective effects through the TREK-1 pathway in vivo and in vitro.
Spinocerebellar ataxia type 27B (SCA27B) in India: insights from a large cohort study suggest ancient origin
De T, Sharma P, Upilli B, Vivekanand A, Bari S, Sonakar AK, Srivastava AK and Faruq M
The ethnic diversity of India provides a unique opportunity to study the history of the origin of mutations of genetic disorders. Spinocerebellar ataxia type 27B (SCA27B), a recently identified dominantly inherited cerebellar disorder is caused by GAA-repeat expansions in intron 1 of Fibroblast Growth Factor 14 (FGF14). Predominantly reported in the European population, we aimed to screen this mutation and study the founder haplotype of SCA27B in Indian ataxia patients.
Kufor-Rakeb syndrome-associated psychosis: a novel loss-of-function ATP13A2 variant and response to antipsychotic therapy
Colijn MA, Vrijsen S, Au PYB, Abou El Asrar R, Houdou M, Van den Haute C, Sarna J, Montgomery G and Vangheluwe P
Biallelic (autosomal recessive) pathogenic variants in ATP13A2 cause a form of juvenile-onset parkinsonism, termed Kufor-Rakeb syndrome. In addition to motor symptoms, a variety of other neurological and psychiatric symptoms may occur in affected individuals, including supranuclear gaze palsy and cognitive decline. Although psychotic symptoms are often reported, response to antipsychotic therapy is not well described in previous case reports/series. As such, we describe treatment response in an individual with Kufor-Rakeb syndrome-associated psychosis. His disease was caused by a homozygous novel loss-of-function ATP13A2 variant (NM_022089.4, c.1970_1975del) that was characterized in this study. Our patient exhibited a good response to quetiapine monotherapy, which he has so far tolerated well. We also reviewed the literature and summarized all previous descriptions of antipsychotic treatment response. Although its use has infrequently been described in Kufor-Rakeb syndrome, quetiapine is commonly used in other degenerative parkinsonian disorders, given its lower propensity to cause extrapyramidal symptoms. As such, quetiapine should be considered in the treatment of Kufor-Rakeb syndrome-associated psychosis when antipsychotic therapy is deemed necessary.
The lethal homozygous variant in the ATP1A2 gene is associated with FARIMPD syndrome phenotypes in newborns
Haj Mohammad Hassani B and Malekzadeh K
FARIMPD (Fetal akinesia, respiratory insufficiency, microcephaly, polymicrogyria, and dysmorphic facies) syndrome is a severe condition caused by ATP1A2 gene variants. The syndrome's novelty and rarity have limited its clinical and molecular knowledge. This research tries to provide new insight by investigating the cause of the early deaths due to FARIMPD syndrome in a particular family and reviewing previous studies. DNA and RNA were extracted from the blood samples of newborns and their parents, followed by whole exome sequencing and segregation analysis. A pathogenic homozygous nonsense variant (c.1234C > T: p.Arg412*) in the ATP1A2 gene was found in newborns. This variant is reported as homozygous for the first time. The migraine symptoms were the result of the heterozygous state of this particular variant, which supported the dominant inheritance pattern of this disease. Real-time PCR was used to analyze ATP1A2 gene expression in the newborns compared to parents and control subjects. The expression analysis also showed significant mRNA degradation in the newborns compared to heterozygous and healthy individuals, due to Nonsense-mediated mRNA Decay phenomena. Our study describes an ATP1A2 nonsense variant (c.1234C > T) that appears compatible with infant survival in the heterozygous and compound heterozygous states but is lethal in the homozygous state.
A novel variant in the GNE gene in a Malian patient presenting with distal myopathy
Kotioumbé M, Maiga AB, Bamba S, Cissé L, Diarra S, Diallo S, Yalcouyé A, Kané F, Diallo SH, Coulibaly D, Coulibaly T, Dembélé K, Maiga B, Guinto CO and Landouré G
GNE-myopathy (GNE-M) is a rare autosomal recessive disorder caused by variants in the GNE gene. We report a novel variant in GNE causing GNE-M in a Malian family. A 19-year-old male patient from consanguineous marriage was seen for progressive walking difficulty. Neurological examination found predominant distal muscle weakness and atrophy, decreased tendon reflexes, predominating in lower limbs. Electroneuromyography showed an axonal neuropathy pattern. However, whole exome sequencing (WES) revealed a novel biallelic variant in GNE c.1838G > A:p.Gly613Glu, segregating with the phenotype within the family. This study highlights its diagnosis challenges in sub-Saharan Africa and broadens the genetic spectrum of this rare disease.
Unveiling the therapeutic prospects of IFNW1 and IFNA21: insights into glioma pathogenesis and clinical significance
Cheng H, Zhao Y, Hou X, Ling F, Wang J, Wang Y and Cao Y
Glioma, a type of brain tumor, poses significant challenges due to its heterogeneous nature and limited treatment options. Interferon-related genes (IRGs) have emerged as potential players in glioma pathogenesis, yet their expression patterns and clinical implications remain to be fully elucidated. We conducted a comprehensive analysis to investigate the expression patterns and functional enrichment of IRGs in glioma. This involved constructing protein-protein interaction networks, heatmap analysis, survival curve plotting, diagnostic and prognostic assessments, differential expression analysis across glioma subgroups, GSVA, immune infiltration analysis, and drug sensitivity analysis. Our analysis revealed distinct expression patterns and functional enrichment of IRGs in glioma. Notably, IFNW1 and IFNA21 were markedly downregulated in glioma tissues compared to normal tissues, and higher expression levels were associated with improved overall survival and disease-specific survival. Furthermore, these genes showed diagnostic capabilities in distinguishing glioma tissues from normal tissues and were significantly downregulated in higher-grade and more aggressive gliomas. Differential expression analysis across glioma subgroups highlighted the association of IFNW1 and IFNA21 expression with key pathways and biological processes, including metabolic reprogramming and immune regulation. Immune infiltration analysis revealed their influence on immune cell composition in the tumor microenvironment. Additionally, elevated expression levels were associated with increased resistance to chemotherapeutic agents. Our findings underscore the potential of IFNW1 and IFNA21 as diagnostic biomarkers and prognostic indicators in glioma. Their roles in modulating glioma progression, immune response, and drug sensitivity highlight their significance as potential therapeutic targets. These results contribute to a deeper understanding of glioma biology and may inform the development of personalized treatment strategies for glioma patients.
Genotypic and phenotypic analysis of Korean patients with tuberous sclerosis complex
Shin HJ, Lee S, Kim SH, Lee JS, Oh JY, Ko A and Kang HC
Tuberous sclerosis complex (TSC) is a rare autosomal dominant disorder caused by mutations in the TSC1 or TSC2 gene. The aim of this study was to analyze the genotypes and phenotypes of Korean patients diagnosed with TSC and expand our understanding of this disorder. This retrospective observational study included 331 patients clinically diagnosed with TSC between November 1990 and April 2023 at Severance Children's Hospital, Seoul, South Korea. The demographic and clinical characteristics of the patients were investigated. Thirty novel variants were identified. Of the 331 patients, 188 underwent genetic testing, and genotype-phenotype variation was analyzed according to the type of gene mutation and functional domain. Fourty-nine patients (49/188, 26%) were had TSC1 mutations, 103 (55%) had TSC2 mutations, and 36 (19%) had no mutation identified (NMI). Hotspots were identified in exons 8 of TSC1 and exons 35 and 41 of TSC2. Patients with TSC2 mutations exhibited a significantly younger age at the time of seizure onset and had refractory epilepsy. Infantile epileptic spasms syndrome (IESS) was more common in the middle mutation domain of TSC2 than in the hamartin domain. Additionally, retinal hamartoma, cardiac rhabdomyoma, and renal abnormalities were significantly associated with TSC2 compared with other gene types. This study contributes to our understanding of TSC by expanding the genotypic spectrum with novel variants and providing insights into the clinical spectrum of patients with TSC in Korea.
Unraveling the three-dimensional (3D) genome architecture in Neurodevelopmental Disorders (NDDs)
Carballo-Pacoret P, Carracedo A and Rodriguez-Fontenla C
The human genome, comprising millions of pairs of bases, serves as the blueprint of life, encoding instructions for cellular processes. However, genomes are not merely linear sequences; rather, the complex of DNA and histones, known as chromatin, exhibits complex organization across various levels, which profoundly influence gene expression and cellular function. Central to understanding genome organization is the emerging field of three-dimensional (3D) genome studies. Utilizing advanced techniques such as Hi-C, researchers have unveiled non-random dispositions of genomic elements, highlighting their importance in transcriptional regulation and disease mechanisms. Topologically Associating Domains (TADs), that demarcate regions of chromatin with preferential internal interactions, play crucial roles in gene regulation and are increasingly implicated in various diseases such as cancer and schizophrenia. However, their role in Neurodevelopmental Disorders (NDDs) remains poorly understood. Here, we focus on TADs and 3D conservation across the evolution and between cell types in NDDs. The investigation into genome organization and its impact on disease has led to significant breakthroughs in understanding NDDs etiology such ASD (Autism Spectrum Disorder). By elucidating the wide spectrum of ASD manifestations, researchers aim to uncover the underlying genetic and epigenetic factors contributing to its heterogeneity. Moreover, studies linking TAD disruption to NDDs underscore the importance of spatial genome organization in maintaining proper brain development and function. In summary, this review highlights the intricate interplay between genome organization, transcriptional control, and disease pathology, shedding light on fundamental biological processes and offering insights into the mechanisms underlying NDDs like ASD.
The role of gut-derived short-chain fatty acids in Parkinson's disease
Saadh MJ, Mustafa AN, Mustafa MA, S RJ, Dabis HK, Prasad GVS, Mohammad IJ, Adnan A and Idan AH
The emerging function of short-chain fatty acids (SCFAs) in Parkinson's disease (PD) has been investigated in this article. SCFAs, which are generated via the fermentation of dietary fiber by gut microbiota, have been associated with dysfunction of the gut-brain axis and, neuroinflammation. These processes are integral to the development of PD. This article examines the potential therapeutic implications of SCFAs in the management of PD, encompassing their capacity to modulate gastrointestinal permeability, neuroinflammation, and neuronal survival, by conducting an extensive literature review. As a whole, this article emphasizes the potential therapeutic utility of SCFAs as targets for the management and treatment of PD.
Impact of flexible assertive community treatment model (FACT) on community rehabilitation of schizophrenia in Southern China
Zhao Y, Zheng S, Zhang H, Zhang Y, Wang Z and Huang Q
Schizophrenia is a group of severe mental illnesses of unknown etiology, most of which are slow or subacute in young adults. 160 adult schizophrenic patients were randomly divided into an intervention group given FACT and a control group given routine mental health follow-up. The scale includes the Positive and Negative Syndrome Scale (PANSS), Social Disability Screening Schedule Scale (SDSS), and the World Health Organization's multicultural quality of life instrument in its brief form Scale(WHOQOL-BREF) were recorded. The average scores of positive scale, negative scale, general psychopathology scale and total score in PANSS scale before intervention(baseline) of the patients in the intervention group were 24.90 ± 5.43, 17.53 ± 3.84, 38.31 ± 4.09 and 80.54 ± 6.75. After 6 months and 12 months of intervention, positive scale, negative scale, general psychopathology scale and total score of the PANSS scale in the intervention group and the total score of SDSS all decreased significantly. The WHOQOL-BREF total score was significantly improved, and the differences were statistically significant (P < 0.05). The FACT intervention model has a significant effect on the rehabilitation of patients with schizophrenia in the community, improves their social function, and improves their quality of life.
Novel splicing variant and gonadal mosaicism in DYRK1A gene identified by whole-genome sequencing in multiplex autism spectrum disorder families
Agha Gholizadeh M, Behjati F, Ghasemi Firouzabadi S, Heidari E, Razmara E, Almadani N, Sharifi Zarchi A and Garshasbi M
Autism spectrum disorder (ASD) is a complex neurodevelopmental condition with considerable genetic heterogeneity. The disorder is clinically diagnosed based on DSM-5 criteria, featuring deficits in social communication and interaction, along with restricted and repetitive behaviours. Here, we performed whole-genome sequencing (WGS) on four individuals with ASD from two multiplex families (MPX), where more than one individual is affected, to identify potential single nucleotide variants (SNVs) and structural variants (SVs) in coding and non-coding regions. A rigorous bioinformatics pipeline was employed for variant detection, followed by segregation analysis. Our investigation revealed an unreported splicing variant in the DYRK1A gene (c.-77 + 2T > C; IVS1 + 2T > C; NM_001396.5), in heterozygote form in two affected children in one of the families (family B), which was absent in the healthy parents and siblings. This finding suggests the presence of gonadal mosaicism in one of the parents, representing the first documented instance of such inheritance for a variant in the DYRK1A gene associated with ASD. Furthermore, we identified a 50 bp deletion in intron 9 of the DLG2 gene in two affected patients from the same family, confirmed by PCR and Sanger sequencing. In Family A, we identified potential candidate variants associated with ASD shared by the two patients. These findings enhance our understanding of the genetic landscape of ASD, particularly in MPX families, and highlight the utility of WGS in uncovering novel genetic contributions to neurodevelopmental disorders.
A perspective on epigenomic aging processes in the human brain and their plasticity in patients with mental disorders - a systematic review
Postberg J, Schubert MT, Nin V, Wagner L and Piefke M
The debate surrounding nature versus nurture remains a central question in neuroscience, psychology, and in psychiatry, holding implications for both aging processes and the etiology of mental illness. Epigenetics can serve as a bridge between genetic predisposition and environmental influences, thus offering a potential avenue for addressing these questions. Epigenetic clocks, in particular, offer a theoretical framework for measuring biological age based on DNA methylation signatures, enabling the identification of disparities between biological and chronological age. This structured review seeks to consolidate current knowledge regarding the relationship between mental disorders and epigenetic age within the brain. Through a comprehensive literature search encompassing databases such as EBSCO, PubMed, and ClinicalTrials.gov, relevant studies were identified and analyzed. Studies that met inclusion criteria were scrutinized, focusing on those with large sample sizes, analyses of both brain tissue and blood samples, investigation of frontal cortex markers, and a specific emphasis on schizophrenia and depressive disorders. Our review revealed a paucity of significant findings, yet notable insights emerged from studies meeting specific criteria. Studies characterized by extensive sample sizes, analysis of brain tissue and blood samples, assessment of frontal cortex markers, and a focus on schizophrenia and depressive disorders yielded particularly noteworthy results. Despite the limited number of significant findings, these studies shed light on the complex interplay between epigenetic aging and mental illness. While the current body of literature on epigenetic aging in mental disorders presents limited significant findings, it underscores the importance of further research in this area. Future studies should prioritize large sample sizes, comprehensive analyses of brain tissue and blood samples, exploration of specific brain regions such as the frontal cortex, and a focus on key mental disorders. Such endeavors will contribute to a deeper understanding of the relationship between epigenetic aging and mental illness, potentially informing novel diagnostic and therapeutic approaches.
Phenotype-genotype spectrum of a cohort of congenital muscular dystrophies: a single-centre experience from India
Chawla T, Nashi S, Baskar D, Polavarapu K, Vengalil S, Bardhan M, Preethish-Kumar V, Sukrutha R, Unnikrishnan G, Huddar A, Padmanabha H, Anjanappa RM, Bevinahalli N, Nittur V, Rajanna M, Arunachal Udupi G and Nalini A
Congenital Muscular Dystrophies (CMD) are phenotypically and genotypically heterogenous disorders with a prevalence of 0.68 to 2.5/100,000, contributing to significant morbidity and mortality. We aimed to study the phenotype-genotype spectrum of genetically confirmed cases of CMD. This was retrospective & descriptive study done at a quaternary care referral centre in south India. Genetically confirmed cases of CMDs seen between 2010 to 2020 were recruited. Detailed clinical history, including pedigree, MRI brain/muscle, next generation sequencing results of 61 CMD cases were collected. Collagen VI-related dystrophy (COL6-RD) (36%) was the most common subtype with variants frequently seen in COL6A1 gene. Other CMDs identified were LAMA2-RD (26%), alpha-dystroglycan-RD (19%), LMNA-RD (8%), CHKB-RD (7%) and SEPN1-RD (3%). Similar to previous cohorts, overall, missense variants were common in COL-6 RD. Variants in triple helical domain (THD) of COL6-RD were seen in 11/22 patients, 5 of whom were ambulatory contrary to previous literature citing severe disease with these variants. However, our follow-up period was shorter. In the LAMA2-RD, 2/16 patients were ambulatory & all 16 carried truncating variants. Among dystroglycanopathies, FKRP-RD was the commonest. Milder phenotype of FKRP- RD was observed with variant c.1343C > T, which was also a recurrent variant in our cohort. p.Arg249Trp variant in LMNA-CMD associated with early loss of ambulation was also identified in 1/5 of our patients who expired at age 2.8 years. The current retrospective series provides detailed clinical features and mutation patterns of genetically confirmed cases of CMD from a single center in India.
A novel missense variant in the ATPase domain of ATP8A2 and review of phenotypic variability of ATP8A2-related disorders caused by missense changes
Flannery KP, Safwat S, Matsell E, Battula N, Hamed AAA, Mohamed IN, Elseed MA, Koko M, Abubaker R, Abozar F, Elsayed LEO, Bhise V, Molday RS, Salih MA, Yahia A and Manzini MC
ATPase, class 1, type 8 A, member 2 (ATP8A2) is a P4-ATPase with a critical role in phospholipid translocation across the plasma membrane. Pathogenic variants in ATP8A2 are known to cause cerebellar ataxia, impaired intellectual development, and disequilibrium syndrome 4 (CAMRQ4) which is often associated with encephalopathy, global developmental delay, and severe motor deficits. Here, we present a family with two siblings born from a consanguineous, first-cousin union from Sudan presenting with global developmental delay, intellectual disability, spasticity, ataxia, nystagmus, and thin corpus callosum. Whole exome sequencing revealed a homozygous missense variant in the nucleotide binding domain of ATP8A2 (p.Leu538Pro) that results in near complete loss of protein expression. This is in line with other missense variants in the same domain leading to protein misfolding and loss of ATPase function. In addition, by performing diffusion-weighted imaging, we identified bilateral hyperintensities in the posterior limbs of the internal capsule suggesting possible microstructural changes in axon tracts that had not been appreciated before and could contribute to the sensorimotor deficits in these individuals.
Frequency of C9orf72, GRN, and MAPT pathogenic variants in patients recruited at the Belgrade Memory Center
Stefanova E, Marjanović A, Dobričić V, Mandić-Stojmenović G, Stojković T, Branković M, Šarčević M, Novaković I and Kostić VS
Most of the heritability in frontotemporal dementia (FTD) is accounted for by autosomal dominant hexanucleotide expansion in the chromosome 9 open reading frame 72 (C9orf72), pathogenic/likely pathogenic variants in progranulin (GRN), and microtubule-associated protein tau (MAPT) genes. Until now, there has been no systematic analysis of these genes in the Serbian population. Herein, we assessed the frequency of the C9orf72 expansion, pathogenic/likely pathogenic variants in GRN and MAPT in a well-characterized group of 472 subjects (FTD, Alzheimer's disease - AD, mild cognitive impairment - MCI, and unspecified dementia - UnD), recruited in the Memory Center, Neurology Clinic, University Clinical Center of Serbia. The C9orf72 repeat expansion was detected in 6.98% of FTD cases (13.46% familial; 2.6% sporadic). In the UnD subgroup, C9orf72 repeat expansions were detected in 4.08% (8% familial) individuals. Pathogenic variants in the GRN were found in 2.85% of familial FTD cases. Interestingly, no MAPT pathogenic/likely pathogenic variants were detected, suggesting possible geographical specificity. Our findings highlight the importance of wider implementation of genetic testing in neurological and psychiatric practice managing patients with cognitive-behavioral and motor symptoms.
Hitting Epstein Barr virus where it hurts: computational methods exploration for siRNA therapy in alleviating Epstein Barr virus-induced multiple sclerosis
Ojo TO, Elegbeleye OE, Bolaji OQ, Adelusi TI, Oladipo EK, Olawuyi MO, Afolayan BO, Oyaronbi AO, Ogunjobi TT, Oyewole MP, Folorunso KP and Ogunlana AT
Multiple sclerosis (MS), an intricate neurological disorder, continues to challenge our understanding of the pivotal interplay between the immune system and the central nervous system (CNS). This condition arises from the immune system's misdirected attack on nerve fiber protection, known as myelin sheath, alongside nerve fibers themselves. This enigmatic condition, characterized by demyelination and varied clinical manifestations, prompts exploration into its multifaceted etiology and potential therapeutic avenues. Research has revealed a potential connection between Epstein Barr virus (EBV), specifically Epstein Barr Nuclear Antigen 1 (EBNA-1), and MS. The immune response to EBNA-1 antigen triggers the production of anti-EBNA-1 molecules, including IgG that identify a similar amino acid sequence to EBNA-1 in myelin, inadvertently targeting myelin sheath and contributing to MS progression. Currently, no treatment exists for EBNA-1-induced MS apart from symptom management. Addressing this, a novel potential therapeutic avenue utilizing small interference RNAs (siRNA) has been designed. By targeting the conserved EBNA-1 gene sequences in EBV types 1 and 2, five potential siRNAs were identified in our analysis. Thorough evaluations encompassing off-target binding, thermodynamics and secondary structure elucidation, efficacy prediction, siRNA-mRNA sequence binding affinity exploration, melting temperature, and docking of siRNAs with human argonaute protein 2 (AGO2) were conducted to elucidate the siRNAs efficiency. These designed siRNA molecules harnessed promising silencing activity in the EBNA-1 gene encoding the EBNA-1 antigen protein and thus have the potential to mitigate the severity of this dangerous virus.
Investigation of genotype-phenotype and familial features of Turkish dystrophinopathy patients
Ozkalayci H, Bora E, Cankaya T, Kocabey M, Zubari NC, Yis U, Giray Bozkaya O, Turan S, Pekcanlar Akay A, Caglayan AO and Ulgenalp A
Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are X-linked recessive allelic muscle diseases caused by dystrophin gene mutations. Eight hundred thirty-seven patients admitted between 1997 and 2022 were included in the study. Two hundred twenty patients were analyzed by multiplex PCR (mPCR) alone. Five hundred ninety-five patients were investigated by multiplex ligation-dependent probe amplification (MLPA), and 54 patients were examined by sequencing. Deletion was detected in 60% (132/220) of the cases in the mPCR group only and in 58.3% (347/595) of the cases with MLPA analysis. The rates of deletion and duplication were 87.7% and 12.3%, respectively, in the MLPA analysis. Single exon deletions were the most common mutation type. The introns 43-55 (81.8%) and exons 2-21 (13.1%) regions were detected as hot spots in deletions. It was determined that 89% of the mutations were suitable for exon skipping therapy. The reading frame rule did not hold in 7.6% of D/BMD cases (17/224). We detected twenty-five pathogenic/likely pathogenic variants in sequencing, five of which were novel variants. Nonsense mutation was the most common small mutation (44%). 21% of DMD patients were familial. We detected germline mosaicism in four families (4.3%) in the large rearrangement group and one gonosomal mosaicism in a family with a nonsense mutation. This is the largest study examining genotype and phenotype data in Turkish D/BMD families investigated by MLPA analysis. The reading frame hypothesis is not valid in all cases. Sharing the genotype and phenotype characteristics of these cases in the literature will shed light on the molecular structure of DMD and guide gene therapy research. In genetic counseling, carrier screening in the family and possible gonadal mosaicism should be emphasized.