Dataset Information

A family with spinocerebellar ataxia type 5 found to have a novel missense mutation within a SPTBN2 spectrin repeat.

ABSTRACT: A family with late-onset autosomal dominant pure cerebellar ataxia, consistent with spinocerebellar ataxia type 5 (SCA5) but lacking previously reported SPTBN2 mutations, was identified. DNA was collected from seven individuals across two generations and the SPTBN2 gene on chromosome 11 was sequenced. A nonsynonymous heterozygous substitution in exon 12 was detected in individuals diagnosed with SCA5 while unaffected family members did not possess this variant. The identified c.1415C>T variant results in a p.T472M substitution in the second SPEC domain of the beta-III spectrin protein. The threonine at position 472 is not in close proximity to the characteristic residues that define the SPEC domain and is variable across diverse SPEC domains, yet is highly conserved in SPTBN2. Consistent with these observations, bioinformatic analysis of the p.T472M variant suggests it to be pathological. Two deletions within the SPTBN2 SPEC domains (E532_M544del and L629_R634delinsW) have been previously reported to cause SCA5, but this is the first missense mutation in this region of the protein shown to likely be pathogenic.

SUBMITTER: Cho E

PROVIDER: S-EPMC3574192 | biostudies-literature | 2013 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

A family with spinocerebellar ataxia type 5 found to have a novel missense mutation within a SPTBN2 spectrin repeat.

Cho Ellen E Fogel Brent L BL

Cerebellum (London, England) 20130401 2

A family with late-onset autosomal dominant pure cerebellar ataxia, consistent with spinocerebellar ataxia type 5 (SCA5) but lacking previously reported SPTBN2 mutations, was identified. DNA was collected from seven individuals across two generations and the SPTBN2 gene on chromosome 11 was sequenced. A nonsynonymous heterozygous substitution in exon 12 was detected in individuals diagnosed with SCA5 while unaffected family members did not possess this variant. The identified c.1415C>T variant r ...[more]

PMID: 22843192

Similar Datasets

Project description:We undertook a gene identification and molecular characterization project in a large kindred originally clinically diagnosed with SCA-X1. While presenting with ataxia, this kindred also had some unique peripheral nervous system features. The implicated region on the X chromosome was delineated using haplotyping. Large deletions and duplications were excluded by array comparative genomic hybridization. Exome sequencing was undertaken in two affected subjects. The single identified X chromosome candidate variant was then confirmed to co-segregate appropriately in all affected, carrier and unaffected family members by Sanger sequencing. The variant was confirmed to be novel by comparison with dbSNP, and filtering for a minor allele frequency of <1% in 1000 Genomes project, and was not present in the NHLBI Exome Sequencing Project or a local database at the BCM HGSC. Functional experiments on transfected cells were subsequently undertaken to assess the biological effect of the variant in vitro. The variant identified consisted of a previously unidentified non-synonymous variant, GJB1 p.P58S, in the Connexin 32/Gap Junction Beta 1 gene. Segregation studies with Sanger sequencing confirmed the presence of the variant in all affected individuals and one known carrier, and the absence of the variant in unaffected members. Functional studies confirmed that the p.P58S variant reduced the number and size of gap junction plaques, but the conductance of the gap junctions was unaffected. Two X-linked ataxias have been associated with genetic loci, with the first of these recently characterized at the molecular level. This represents the second kindred with molecular characterization of X-linked ataxia, and is the first instance of a previously unreported GJB1 mutation with a dominant and permanent ataxia phenotype, although different CNS deficits have previously been reported. This pedigree has also been relatively unique in its phenotype due to the presence of central and peripheral neural abnormalities. Other X-linked SCAs with unique features might therefore also potentially represent variable phenotypic expression of other known neurological entities.

Dataset Information

A family with spinocerebellar ataxia type 5 found to have a novel missense mutation within a SPTBN2 spectrin repeat.

Publications

A family with spinocerebellar ataxia type 5 found to have a novel missense mutation within a SPTBN2 spectrin repeat.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets