Neurology-Genetics最新文献

Some epilepsy syndromes are more common in female individuals. Often, these syndromes have an underlying genetic variant involving the X chromosome that is typically lethal in male individuals, resulting in a higher female prevalence. However, some of the idiopathic generalized epilepsies such as juvenile myoclonic epilepsy are conditions with complex inheritance, with thousands of variants in genes throughout the genome. But they can also have a predominance in female individuals. In this study, we performed a narrative review of PubMed and Scopus using the following entries: "epilepsy in women," "genetic epilepsy in female individuals," "epilepsy genetics in women," "female-specific epilepsy genetics," "epilepsy and genetic mutations in female individuals." The findings were synthesized and described according to clinical characteristics, underlying genetic mechanisms, and treatment considerations for these epilepsy syndromes manifesting largely in female individuals. The epilepsy syndromes reviewed here include Rett syndrome, CDKL5 deficiency disorder, PCDH19-related epilepsy, subcortical band heterotopia, periventricular heterotopia, Aicardi syndrome, and juvenile myoclonic epilepsy. Recognizing these epilepsy syndromes and understanding their underlying genetic etiology helps provide a tailored treatment approach early in the course of the disease. It can also assist with genetic counselling for family members who plan to have children.

Background and objectives: Mild malformation of cortical development with oligodendroglial hyperplasia and epilepsy (MOGHE) is a newly described rare entity of drug-resistant epilepsy, with a wide spectrum of presentations. We aim to describe the diagnostic features and prognosis of MOGHE in a large cohort.

Methods: We performed a systematic review preregistered on PROSPERO (CRD42023472978), in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. We searched PubMed, Embase, Scopus, and ScienceDirect between database inception and November 30, 2023, for all published studies on MOGHE. Inclusion criteria were a histopathologic diagnosis of MOGHE. The risk of bias was analyzed with a standardized tool specifically for case reports and case series. The demographic, clinical, EEG, neuroimaging, genetic, and neuropathologic features; treatments; and prognosis were extracted and analyzed. Subgroup analysis was performed with the age at onset and SLC35A2 variant status.

Results: A total of 163 patients with MOGHE from 18 studies were included in the analysis. The median age at seizure onset was 1.2 years, and 103 were male. Ninety-five patients presented with unilobed lesions. Ninety-nine had lesions in the frontal lobe. A total of 101 patients achieved a favorable surgical outcome. Patients with an onset before 10 years were more likely to present with epileptic spasms, the West syndrome, a circumscribed pattern of interictal EEG, intellectual disabilities, and a better seizure outcome, compared with those with an onset age 10 years and older. Forty-five patients (72.6%) were SLC35A2-positive. Patients harboring the SLC35A2 variants were more likely to present as Lennox-Gastaut syndrome, when compared with those who were SLC35A2-negative.

Discussion: MOGHE is a distinct entity of drug-resistant epilepsy associated with SLC35A2 variants, characterized by age-dependent phenotypes. The study emphasizes the clinical pearls indicative of the rare disease, which may facilitate early recognition and appropriate selection of treatments. The included studies were case reports or series, which were mainly limited by selection and reporting biases.

Alzheimer disease (AD), the most common dementing syndrome in the United States, is currently established by the presence of amyloid-β and tau protein biomarkers in the setting of clinical cognitive impairment. These straightforward diagnostic parameters belie an immense complexity of genetic architecture underlying risk and presentation in AD. In this review, we provide a focused overview of the current state of AD genetics. We discuss the discovery of familial autosomal dominant genes, the identification of candidate genes associated with AD, and genetic variants conferring higher risk of developing AD compared with the general population. In particular, we discuss important features of AD risk due to the APOE ε4 allele. In addition to risk, we describe how the field has made headway understanding genetic factors that may protect from AD. The biological implications and practical limitations of information gleaned from genome-wide association studies in AD over the years are also discussed. The readers will have an up-to-date understanding of where we are in our efforts to understand the layers of genetic complexity in AD.

Spinocerebellar ataxias (SCAs) are dominantly inherited diseases that lead to neurodegeneration in the cerebellum and other parts of the nervous system. This review examines the progress that has been made in SCA2 from its initial clinical description to discovery of DNA CAG-repeat expansions in the ATXN2 gene. ATXN2 repeat alleles cover the range from recessive and dominant mendelian alleles to risk alleles for amyotrophic lateral sclerosis. We review studies aimed at defining the normal function of ATXN2 and mutant ATXN2 using cellular and mouse models. Progress in testing small compounds and antisense oligonucleotides in preclinical studies is described as well including our recent focus on staufen-1 (STAU1) and mRNA metabolism and control of autophagy.

UK Biobank is a large-scale prospective study with extensive genetic and phenotypic data from half a million adults. Participants, aged 40 to 69, were recruited from the general UK population between 2006 and 2010. During recruitment, participants completed questionnaires covering lifestyle and medical history, underwent physical measurements, and provided biological samples for long-term storage. Whole-cohort assays have been conducted, including biochemical markers, genotyping, whole-exome and whole-genome sequencing, as well as proteomics and metabolomics in large subsets of the cohort, with potential for additional assays in the future. Participants consented to link their data to electronic health records, enabling the identification of health outcomes over time. Research studies using UK Biobank data have already enhanced our understanding of the role of genetic variation in neurologic disease, offering insights into potential therapeutic approaches. The integration of genetic and imaging data has led to significant discoveries regarding the relationship between genetic variants and brain structure and function, particularly in Alzheimer disease and Parkinson disease. Genetic data have also allowed Mendelian randomization analyses to be performed, enabling further investigation into the causality of associations between behavioral and physiologic factors-such as diet and blood pressure-and neurologic outcomes. Furthermore, genetic and proteomic data have been particularly useful in identifying new drug targets for neurologic disease and in enhancing risk prediction algorithms that are increasingly applied in clinical practice to identify those at higher risk. As UK Biobank continues to be enhanced, and the cases of neurologic disease accrue over time, the study will become increasingly valuable for both discovery and translational research on genetics and neurologic disease.

Background and objectives: Migraine is strongly comorbid with irritable bowel syndrome (IBS), one of several gastrointestinal (GI) conditions that are distinguished by symptomatic profiles that are partly overlapping. Potential shared mechanisms of migraine and the GI conditions were investigated by assessing shared genetics on a genome-wide basis.

Methods: Analyses leveraged genome-wide summary statistics from large-scale genetic studies for migraine, including by aura status, IBS, peptic ulcer disease (PUD), gastrointestinal reflux (GERD), functional dyspepsia (FD), diverticular disease (DD), and the immune-related inflammatory bowel disease (IBD) or its constituents, ulcerative colitis (UC) and Crohn disease (CD). Genetic correlation was evaluated on a genome-wide basis and at independent local regions, including those related to therapeutic targeting of serotonin and the calcitonin gene-related peptide. Genetic correlation was assessed for enrichment at genes according to tissue specificity of gene expression. Potential causality between migraine and the GI conditions was assessed by Mendelian randomization.

Results: Genetic correlation with migraine was strongly significant among the nonimmune GI disorders, maximally for IBS (rg [SE] = 0.37[0.04], p = 10^-21) and minimally for DD (0.18 (0.04), 7.5 × 10^-7), but null for IBD. There were distinct patterns of local genetic sharing with migraine across the GI conditions at 22 significant segments of the genome, 7 of which were novel for either migraine or GI or both. Enrichment analysis suggested involvement of the CNS in genetic overlap of GERD, IBS, and PUD with migraine. There was local genetic sharing with migraine at CALCA/CALCB (encoding calcitonin gene-related peptide [CGRP]) in an inverse sense for GERD and PUD, but with concordance and greater significance for DD, IBD, and UC. Mendelian randomization supported causal effects of PUD, GERD and particularly DD (OR[SE] = 1.90 (1.35-2.68, p = 2.2 × 10^-4) on migraine, but not of migraine on any GI condition.

Discussion: Genetic sharing of migraine and non-immune-related GI disorders was extensive yet distinct across GI disorders that have overlapping symptoms, with enrichment signals that imply neurologic mechanisms. Causal effects of some GI conditions on migraine were supported. A concordant local correlation at CALCA/CALCB of migraine with both DD and the immune-related disorders suggests potential benefit to these conditions from repurposed migraine therapeutics targeting CGRP.

Background and objectives: In the era of precision medicine, genetic test results have become increasingly relevant in the care of patients with Parkinson disease (PD). While large research consortia are performing widespread research genetic testing to accelerate discoveries, debate continues about whether, and to what extent, the results should be returned to patients. Ethically, it is imperative to keep participants informed, especially when findings are potentially actionable. However, research testing may not hold the same standards required from clinical diagnostic laboratories and hold significant psychosocial implications. The absence of universally recognized protocols complicates the establishment of appropriate guidelines.

Methods: Aiming to develop recommendations on return of research results (RoR) practice within the Global Parkinson's Genetics Program (GP2), we conducted a global survey to gain insight on GP2 members' perceptions, practice, readiness, and needs surrounding RoR.

Results: GP2 members (n = 191), representing 147 institutions and 60 countries across 6 continents, completed the survey. Access to clinical genetic testing services was significantly higher in high-income countries compared with low- and middle-income countries (96.6% vs 58.4%), where funding was predominantly covered by patients themselves. While 92.7% of the respondents agreed that genetic research results should be returned, levels of agreement were higher for clinically relevant results relating to pathogenic or likely pathogenic variants in genes known to cause PD or other neurodegenerative diseases. Less than 10% offered separate clinically accredited genetic testing before returning genetic research results. A total of 48.7% reported having a specific statement on RoR policy in their ethics consent form, while 53.9% collected data on participants' preferences on RoR prospectively. 24.1% had formal genetic counselling training. Notably, the comfort level in returning incidental genetic findings or returning results to unaffected individuals remains low.

Discussion: Given the differences in resources and training for RoR, as well as ethical and regulatory considerations, tailored approaches are required to ensure equitable access to RoR. Several identified strategies to enhance RoR practices include improving informed consent processes, increasing capacity for genetic counselling including providing counselling toolkits for common genetic variants, broadening access to sustainable clinically accredited testing, building logistical infrastructure for RoR processes, and continuing public and health care education efforts on the important role of genetics in PD.

Background and objectives: Nemaline myopathy type 6 (NEM6) is the most prevalent type of nemaline myopathy in the Netherlands. Because a detailed clinical characterization is not available yet, we here provide a detailed assessment of 24 patients.

Methods: In this cross-sectional study, we performed a full clinical assessment (medical history and neurologic examination) in patients with NEM6. Patient demographics, causative variants in the KBTBD13 gene, creatine kinase levels, and the results of previous muscle biopsies were collected. We evaluated experienced health-related quality of life, fatigue severity, prevalence of falls, balance control (Mini-Balance Evaluation Systems Test [Mini-BESTest]), functional motor score (Motor Function Measure [MFM]), and 6-minute walk distance. We used transcranial magnetic stimulation to assess muscle relaxation kinetics.

Results: Twenty-four patients were included (19 women [19-76 years]; 5 men [25-57 years]). Key patient-reported symptoms since childhood were muscle weakness (n = 23; 96%), slowness of movements (n = 23; 96%), and difficulties with running (n = 20; 83%). Axial, proximal, and distal muscles showed mild weakness in most patients. Health-related quality of life was significantly lower, and there was a significantly increased fatigue severity compared with controls. Prospectively, in a period of 100 days, 8 patients (33%) fell at least 1 time, of whom 5 patients (21%) fell 2 times or more. The median total score on the Mini-BESTest was 24 (21.0-26.0 [interquartile range]) of 28 and the median total percentage on the MFM was 91% (83.5-95.3), both considered to be mildly abnormal. The 6-minute walk distance was below the lower limit of normal in 4 patients (17%). All patients with NEM6 showed a markedly reduced muscle relaxation rate with a median of 6.5 [4.9-8.1] s^-1 (lower limit of normal is 10.1 s^-1).

Discussion: This cross-sectional study in patients with NEM6 shows a relatively mild clinical phenotype and mildly abnormal functional tests. However, patients report an important impact on the daily activities, which is illustrated by functional difficulties, reduced quality of life, increased fatigue severity, and increased prevalence of falls. This might be related to delayed muscle relaxation. This study provides a comprehensive overview of the clinical presentation and functional limitations in patients with NEM6.