Short tandem repeat expansions in are absent in cohorts of familial and sporadic amyotrophic lateral sclerosis patients of European ancestry.

In patients of Asian ancestry, a heterozygous CGG repeat expansion of >100 units in is the cause of oculopharyngodistal myopathy type 1 (OPDM1). Repeat lengths of between 61 and 100 units have been associated with rare amyotrophic lateral sclerosis (ALS) cases of Asian ancestry, although with unusually long disease duration and without significant upper motor neuron involvement. This study sought to determine whether CGG repeat expansions were also present in ALS patients of European ancestry.

ALS/FTD-associated mutation in cyclin F inhibits ER-Golgi trafficking, inducing ER stress, ERAD and Golgi fragmentation.

Amyotrophic lateral sclerosis (ALS) is a severely debilitating neurodegenerative condition that is part of the same disease spectrum as frontotemporal dementia (FTD). Mutations in the CCNF gene, encoding cyclin F, are present in both sporadic and familial ALS and FTD. However, the pathophysiological mechanisms underlying neurodegeneration remain unclear.

RNA sequencing of peripheral blood in amyotrophic lateral sclerosis reveals distinct molecular subtypes: Considerations for biomarker discovery.

Aim: Amyotrophic lateral sclerosis (ALS) is a heterogeneous neurodegenerative disease with limited therapeutic options. A key factor limiting the development of effective therapeutics is the lack of disease biomarkers. We sought to assess whether biomarkers for diagnosis, prognosis or cohort stratification could be identified by RNA sequencing (RNA-seq) of ALS patient peripheral blood.

Characterising the Genetic Landscape of Amyotrophic Lateral Sclerosis: A Catalogue and Assessment of Over 1,000 Published Genetic Variants.

Background: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with genetic and phenotypic heterogeneity. Pathogenic genetic variants remain the only validated cause of disease, the majority of which were discovered in familial ALS patients. While causal gene variants are a lesser contributor to sporadic ALS, an increasing number of risk alleles (low penetrance genetic variants associated with a small increase in disease risk) and variants of uncertain significance have been reported.

The E3 Ubiquitin Ligase SCF Cyclin F Promotes Sequestosome-1/p62 Insolubility and Foci Formation and is Dysregulated in ALS and FTD Pathogenesis.

Amyotrophic lateral sclerosis (ALS)- and frontotemporal dementia (FTD)-linked mutations in CCNF have been shown to cause dysregulation to protein homeostasis. CCNF encodes for cyclin F, which is part of the cyclin F-E3 ligase complex SCF known to ubiquitylate substrates for proteasomal degradation. In this study, we identified a function of cyclin F to regulate substrate solubility and show how cyclin F mechanistically underlies ALS and FTD disease pathogenesis.

Short tandem repeat expansions in sporadic amyotrophic lateral sclerosis and frontotemporal dementia.

Pathogenic short tandem repeat (STR) expansions cause over 20 neurodegenerative diseases. To determine the contribution of STRs in sporadic amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), we used ExpansionHunter, REviewer, and polymerase chain reaction validation to assess 21 neurodegenerative disease-associated STRs in whole-genome sequencing data from 608 patients with sporadic ALS, 68 patients with sporadic FTD, and 4703 matched controls. We also propose a data-derived outlier detection method for defining allele thresholds in rare STRs.

Identity-by-descent analysis of CMTX3 links three families through a common founder.

A large 78 kb insertion from chromosome 8q24.3 into Xq27.1 was identified as the cause of CMTX3 in three families of European descent from Australia (CMT193, CMT180) and New Zealand/United Kingdom (CMT623).

Association between DNA methylation variability and self-reported exposure to heavy metals.

Individuals encounter varying environmental exposures throughout their lifetimes. Some exposures such as smoking are readily observed and have high personal recall; others are more indirect or sporadic and might only be inferred from long occupational histories or lifestyles. We evaluated the utility of using lifetime-long self-reported exposures for identifying differential methylation in an amyotrophic lateral sclerosis cases-control cohort of 855 individuals.

NEK1 and STMN2 short tandem repeat lengths are not associated with Australian amyotrophic lateral sclerosis risk.

Sporadic amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with a complex genetic architecture. The lengths of two short tandem repeats (STRs), at the NEK1 and STMN2 loci, were recently associated with ALS risk in cohorts of European descent. The STMN2 STR was proposed to be predictive of clinical features including the age of onset and disease duration in bulbar onset cases.

Simultaneous Isolation of High-Quality RNA and DNA From Postmortem Human Central Nervous System Tissues for Omics Studies.

Multi-omics approaches are increasingly being adopted to understand the complex networks underlying disease. The coisolation of high-quality nucleotides from affected tissues is paramount for the parallel analysis of transcriptomic, genomic, and epigenomic data sets. Although nucleotides extracted from postmortem central nervous system (CNS) tissue are widely used in the study of neurodegenerative disease, assessment of methods for the simultaneous isolation of DNA and RNA is limited.

Common and rare variant association analyses in amyotrophic lateral sclerosis identify 15 risk loci with distinct genetic architectures and neuron-specific biology.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with a lifetime risk of one in 350 people and an unmet need for disease-modifying therapies. We conducted a cross-ancestry genome-wide association study (GWAS) including 29,612 patients with ALS and 122,656 controls, which identified 15 risk loci. When combined with 8,953 individuals with whole-genome sequencing (6,538 patients, 2,415 controls) and a large cortex-derived expression quantitative trait locus (eQTL) dataset (MetaBrain), analyses revealed locus-specific genetic architectures in which we prioritized genes either through rare variants, short tandem repeats or regulatory effects.

Association of Variants in the SPTLC1 Gene With Juvenile Amyotrophic Lateral Sclerosis.

Importance: Juvenile amyotrophic lateral sclerosis (ALS) is a rare form of ALS characterized by age of symptom onset less than 25 years and a variable presentation.

Objective: To identify the genetic variants associated with juvenile ALS.

Design, Setting, And Participants: In this multicenter family-based genetic study, trio whole-exome sequencing was performed to identify the disease-associated gene in a case series of unrelated patients diagnosed with juvenile ALS and severe growth retardation.

Splicing factor proline and glutamine rich intron retention, reduced expression and aggregate formation are pathological features of amyotrophic lateral sclerosis.

Aim: Splicing factor proline and glutamine rich (SFPQ) is an RNA-DNA binding protein that is dysregulated in Alzheimer's disease and frontotemporal dementia. Dysregulation of SFPQ, specifically increased intron retention and nuclear depletion, has been linked to several genetic subtypes of amyotrophic lateral sclerosis (ALS), suggesting that SFPQ pathology may be a common feature of this heterogeneous disease. Our study aimed to investigate this hypothesis by providing the first comprehensive assessment of SFPQ pathology in large ALS case-control cohorts.

Polygenic risk score analysis for amyotrophic lateral sclerosis leveraging cognitive performance, educational attainment and schizophrenia.

Amyotrophic Lateral Sclerosis (ALS) is recognised to be a complex neurodegenerative disease involving both genetic and non-genetic risk factors. The underlying causes and risk factors for the majority of cases remain unknown; however, ever-larger genetic data studies and methodologies promise an enhanced understanding. Recent analyses using published summary statistics from the largest ALS genome-wide association study (GWAS) (20,806 ALS cases and 59,804 healthy controls) identified that schizophrenia (SCZ), cognitive performance (CP) and educational attainment (EA) related traits were genetically correlated with ALS.

Meta-analysis of genome-wide DNA methylation identifies shared associations across neurodegenerative disorders.

Background: People with neurodegenerative disorders show diverse clinical syndromes, genetic heterogeneity, and distinct brain pathological changes, but studies report overlap between these features. DNA methylation (DNAm) provides a way to explore this overlap and heterogeneity as it is determined by the combined effects of genetic variation and the environment. In this study, we aim to identify shared blood DNAm differences between controls and people with Alzheimer's disease, amyotrophic lateral sclerosis, and Parkinson's disease.

Genetic analysis of GLT8D1 and ARPP21 in Australian familial and sporadic amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease caused by the progressive degeneration of motor neurons. Recently, genetic variants in GLT8D1 and ARPP21 were associated with ALS in a cohort of European descent. A synergistic relationship was proposed between ALS associated variants in GLT8D1 and ARPP21.

Evidence for polygenic and oligogenic basis of Australian sporadic amyotrophic lateral sclerosis.

Background: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with phenotypic and genetic heterogeneity. Approximately 10% of cases are familial, while remaining cases are classified as sporadic. To date, >30 genes and several hundred genetic variants have been implicated in ALS.