Browse
Submit Data
Databases
API
Help

Dataset Information

31 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

SIGMAR1 gene mutation causing Distal Hereditary Motor Neuropathy in a Portuguese family.

ABSTRACT: SIGMAR1 gene encodes a non-opioid endoplasmic reticulum (ER) protein which is involved in a large diversity of cell functions and is expressed ubiquitously in both central and peripheral nervous systems. Alterations of its normal function may contribute to two different phenotypes: juvenile amyotrophic lateral sclerosis (ALS 16) and distal hereditary motor neuropathies (dHMN). We present the case of a female patient, of 37-years-old, with distal muscle weakness and atrophy beginning in childhood and slowly progressive in the first two decades of life. Neurological examination revealed a symmetrical severe muscle wasting and weakness in distal lower and upper limbs, with claw hands, footdrop with equinovarus deformity and hammer toes, generalized areflexia and normal sensory examination. The electrodiagnostic study revealed a pure chronic motor peripheral nerve involvement without signs of demyelination. The molecular study found the deletion c.561_576del on exon 4 and a deletion of all exon 4, in the SIGMAR1 gene.

SUBMITTER: Almendra L

PROVIDER: S-EPMC6060428 | biostudies-literature | 2018 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Further Validation of the SIGMAR1 c.151+1G>T Mutation as Cause of Distal Hereditary Motor Neuropathy.

Project description:Distal hereditary motor neuropathies represent a group of rare genetic disorders characterized by progressive distal motor weakness without sensory loss. Their genetic heterogeneity is high and thus eligible for diagnostic whole exome sequencing. The authors report successful application of whole exome sequencing in diagnosing a second consanguineous family with distal hereditary motor neuropathy due to a homozygous c.151+1G>T variant in SIGMAR1. This variant was recently proposed as causal for the same condition in a consanguineous Chinese family. Compared to this family, the Afghan ethnic origin of our patient is distinct, yet the features are identical, validating the SIGMAR1 deficiency phenotype: progressive muscle wasting/weakness in lower and upper limbs without sensory loss. Rapid disease progression during adolescent growth is similar and may be due to SIGMAR1's role in regulating axon elongation and tau phosphorylation. Finally, the authors conclude that SIGMAR1 deficiency should be added to the differential diagnosis of distal hereditary motor neuropathies.

| S-EPMC5417346 | biostudies-literature

Alanyl-tRNA synthetase mutation in a family with dominant distal hereditary motor neuropathy.

Project description:OBJECTIVE: To identify a new genetic cause of distal hereditary motor neuropathy (dHMN), which is also known as a variant of Charcot-Marie-Tooth disease (CMT), in a Chinese family. METHODS: We investigated a Chinese family with dHMN clinically, electrophysiologically, and genetically. We screened for the mutations of 28 CMT or related pathogenic genes using an originally designed microarray resequencing DNA chip. RESULTS: Investigation of the family history revealed an autosomal dominant transmission pattern. The clinical features of the family included mild weakness and wasting of the distal muscles of the lower limb and foot deformity, without clinical sensory involvement. Electrophysiologic studies revealed motor neuropathy. MRI of the lower limbs showed accentuated fatty infiltration of the gastrocnemius and vastus lateralis muscles. All 4 affected family members had a heterozygous missense mutation c.2677G>A (p.D893N) of alanyl-tRNA synthetase (AARS), which was not found in the 4 unaffected members and control subjects. CONCLUSION: An AARS mutation caused dHMN in a Chinese family. AARS mutations result in not only a CMT phenotype but also a dHMN phenotype.

| S-EPMC3359507 | biostudies-literature

Mutations in the SIGMAR1 gene cause a distal hereditary motor neuropathy phenotype mimicking ALS: Report of two novel variants.

Project description:Distal hereditary motor neuropathy (dHMN) is an inherited neuromuscular disease characterized by symmetric distal weakness and atrophy without sensory changes. There are about thirty known genes associated with dHMN, but together they explain only about a third of cases. Mutations in the sigma non-opioid intracellular receptor 1 gene (SIGMAR1) has been linked to autosomal recessive dHMN with pyramidal signs in several families. This phenotype can mimic amyotrophic lateral sclerosis (ALS). We report a 39-year-old man who was referred to our ALS clinic with distal motor weakness and hyperreflexia. Whole exome sequencing identified two novel variants in the SIGMAR1 gene in the proband. Targeted Sanger sequencing of asymptomatic family members confirmed that each carried one of these two variants. Our findings expand the number of known SIGMAR1 pathogenic variants associated with dHMN, which should be clinically distinguished from ALS.

| S-EPMC7387213 | biostudies-literature

A recurrent GARS mutation causes distal hereditary motor neuropathy.

Project description:We found a p.Gly327Arg mutation in GARS in two unrelated women, both of whom had a similar phenotype - motor weakness that began in late childhood, distal weakness in the arms and legs, a motor greater than sensory neuropathy with slowing of motor and not sensory conduction velocities. A de novo mutation was proven in one patient and suspected in the other. The p.Gly327Arg GARS variant did not support yeast growth in a complementation assay, showing that this variant severely impairs protein function. Thus, the p.Gly327Arg GARS mutation causes a distal motor neuropathy.

| S-EPMC6910989 | biostudies-literature

A Novel Mutation of GARS in a Chinese Family With Distal Hereditary Motor Neuropathy Type V.

Project description:Glycyl-tRNA synthetase (GARS) gene mutations have been reported to be associated with Charcot-Marie-Tooth disease 2D and distal hereditary motor neuropathy type V (dHMN-V). In this study, we report a novel GARS mutation in a Chinese family with dHMN-V. Clinical, electromyogram, genetic, and functional data were explored. The proband was an 11-year-old girl presented with progressive distal limb muscle weakness and atrophy due to peripheral motor neuropathy for 1 year. Another five members from three successive generations of the family showed similar symptoms during their first to second decades and demonstrated an autosomal dominant inheritance. The results of genetic testing revealed a novel c.383T>G mutation in the GARS gene in the affected individuals, showing apparent genetic cosegregation. Further bioinformatic analyses showed that the c.383T > G mutation resulted in L128R alteration in the second functional protein domain, and the mutation site was well conserved among different species. In silico analysis predicted that this mutation probably affected protein function. In vitro, this GARS mutation led to a different protein localization pattern than that of the wild-type enzyme. The study found a novel GARS mutation of c.383T > G causing dHMN-V with subcellular localization abnormity in a genetic cosegregation family. These findings broaden the mutational spectrum of GARS.

| S-EPMC6064823 | biostudies-literature

A novel <i>VRK1</i> mutation associated with recessive distal hereditary motor neuropathy.

Project description:Vaccinia-related kinase 1 (VRK1) mutations can cause motor phenotypes including axonal sensorimotor neuropathy, distal hereditary motor neuropathy (dHMN), spinal muscular atrophy, and amyotrophic lateral sclerosis. Here, we identify a novel homozygous VRK1 p.W375X mutation causing recessive dHMN. The proband presented with juvenile onset of weakness in the distal lower extremities, slowly progressing to the distal upper limbs, with bilateral pes cavus and no upper motor or sensory neuron involvement. Nerve conduction studies showed a pure motor axonal neuropathy. Our findings extend the ethnic distribution of VRK1 mutations, indicating that these mutations should be included in genetic diagnostic testing for dHMN.

| S-EPMC6389749 | biostudies-literature

Distal hereditary motor neuronopathy of the Jerash type is caused by a novel SIGMAR1 c.500A>T missense mutation.

Project description:BACKGROUND:Distal hereditary motor neuronopathies (dHMN) are a group of genetic disorders characterised by motor neuron degeneration leading to muscle weakness that are caused by mutations in various genes. HMNJ is a distinct form of the disease that has been identified in patients from the Jerash region of Jordan. Our aim was to identify and characterise the genetic cause of HMNJ. METHODS:We used whole exome and Sanger sequencing to identify a novel genetic variant associated with the disease and then carried out immunoblot, immunofluorescence and apoptosis assays to extract functional data and clarify the effect of this novel SIGMAR1 mutation. Physical and neurological examinations were performed on selected patients and unaffected individuals in order to re-evaluate clinical status of patients 20 years after the initial description of HMNJ as well as to evaluate new and previously undescribed patients with HMNJ. RESULTS:A homozygous missense mutation (c.500A>T, N167I) in exon 4 of the SIGMAR1 gene was identified, cosegregating with HMNJ in the 27 patients from 7 previously described consanguineous families and 3 newly ascertained patients. The mutant SIGMAR1 exhibits reduced expression, altered subcellular distribution and elevates cell death when expressed. CONCLUSION:In conclusion, the homozygous SIGMAR1 c.500A>T mutation causes dHMN of the Jerash type, possibly due to a significant drop of protein levels. This finding is in agreement with other SIGMAR1 mutations that have been associated with autosomal recessive dHMN with pyramidal signs; thus, our findings further support that SIGMAR1 be added to the dHMN genes diagnostic panel.

| S-EPMC7042970 | biostudies-literature

Exome sequencing identifies a REEP1 mutation involved in distal hereditary motor neuropathy type V.

Project description:The distal hereditary motor neuropathies (dHMNs) are a heterogeneous group of neurodegenerative disorders affecting the lower motoneuron. In a family with both autosomal-dominant dHMN and dHMN type V (dHMN/dHMN-V) present in three generations, we excluded mutations in all genes known to be associated with a dHMN phenotype through Sanger sequencing and defined three potential loci through linkage analysis. Whole-exome sequencing of two affected individuals revealed a single candidate variant within the linking regions, i.e., a splice-site alteration in REEP1 (c.304-2A>G). A minigene assay confirmed complete loss of splice-acceptor functionality and skipping of the in-frame exon 5. The resulting mRNA is predicted to be expressed at normal levels and to encode an internally shortened protein (p.102_139del). Loss-of-function REEP1 mutations have previously been identified in dominant hereditary spastic paraplegia (HSP), a disease associated with upper-motoneuron pathology. Consistent with our clinical-genetic data, we show that REEP1 is strongly expressed in the lower motoneurons as well. Upon exogeneous overexpression in cell lines we observe a subcellular localization defect for p.102_139del that differs from that observed for the known HSP-associated missense mutation c.59C>A (p.Ala20Glu). Moreover, we show that p.102_139del, but not p.Ala20Glu, recruits atlastin-1, i.e., one of the REEP1 binding partners, to the altered sites of localization. These data corroborate the loss-of-function nature of REEP1 mutations in HSP and suggest that a different mechanism applies in REEP1-associated dHMN.

| S-EPMC3397265 | biostudies-literature

A recurrent WARS mutation is a novel cause of autosomal dominant distal hereditary motor neuropathy.

Project description:Distal hereditary motor neuropathy is a heterogeneous group of inherited neuropathies characterized by distal limb muscle weakness and atrophy. Although at least 15 genes have been implicated in distal hereditary motor neuropathy, the genetic causes remain elusive in many families. To identify an additional causal gene for distal hereditary motor neuropathy, we performed exome sequencing for two affected individuals and two unaffected members in a Taiwanese family with an autosomal dominant distal hereditary motor neuropathy in which mutations in common distal hereditary motor neuropathy-implicated genes had been excluded. The exome sequencing revealed a heterozygous mutation, c.770A > G (p.His257Arg), in the cytoplasmic tryptophanyl-tRNA synthetase (TrpRS) gene (WARS) that co-segregates with the neuropathy in the family. Further analyses of WARS in an additional 79 Taiwanese pedigrees with inherited neuropathies and 163 index cases from Australian, European, and Korean distal hereditary motor neuropathy families identified the same mutation in another Taiwanese distal hereditary motor neuropathy pedigree with different ancestries and one additional Belgian distal hereditary motor neuropathy family of Caucasian origin. Cell transfection studies demonstrated a dominant-negative effect of the p.His257Arg mutation on aminoacylation activity of TrpRS, which subsequently compromised protein synthesis and reduced cell viability. His257Arg TrpRS also inhibited neurite outgrowth and led to neurite degeneration in the neuronal cell lines and rat motor neurons. Further in vitro analyses showed that the WARS mutation could potentiate the angiostatic activities of TrpRS by enhancing its interaction with vascular endothelial-cadherin. Taken together, these findings establish WARS as a gene whose mutations may cause distal hereditary motor neuropathy and alter canonical and non-canonical functions of TrpRS.

| S-EPMC6248622 | biostudies-literature

Distal hereditary motor neuropathy in Korean patients with a small heat shock protein 27 mutation.

Project description:Distal hereditary motor neuropathy (dHMN) is a heterogeneous disorder characterized by degeneration of motor nerves in the absence of sensory abnormalities. Recently, mutations in the small heat shock protein 27 (HSP27) gene were found to cause dHMN type II or Charcot-Marie-Tooth disease type 2F (CMT2F). The authors studied 151 Korean axonal CMT or dHMN families, and found a large Korean dHMN type II family with the Ser135Phe mutation in HSP27. This mutation was inherited in an autosomal dominant manner, and was well associated with familial members with the dHMN phenotype. This mutation site is located in the alpha-crystallin domain and is highly conserved between different species. The frequency of this HSP27 mutation in Koreans was 0.6%. Magnetic resonance imaging analysis revealed that fatty infiltrations tended to progressively extend distal to proximal muscles in lower extremities. In addition, fatty infiltrations in thigh muscles progressed to affect posterior and anterior compartments but to lesser extents in medial compartment, which differs from CMT1A patients presenting with severe involvements of posterior and medial compartments but less involvement of anterior compartment. The authors describe the clinical and neuroimaging findings of the first Korean dHMN patients with the HSP27 Ser135Phe mutation. To our knowledge, this is the first report of the neuroimaging findings of dHMN type II.

| S-EPMC2679293 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data