Spinocerebellar ataxia type 10 (SCA 10) is an autosomal dominant disease characterized by cerebellar ataxia, seizure and anticipation. The SCA1O mutation is a massive (4-22 kb) expansion of the ATTCT pentanucleotide repeat in intron 9 of E46, a novel gene of unknown function, on chromosome 22q13.3. The long-term objective of this project is to elucidate the molecular mechanisms of SCA1 0, and to develop rational treatment strategies based on the disease-causing mechanism for this progressive debilitating disease. This application will investigate the mechanism by which the expanded ATTCT repeat leads to the disease phenotype. The hypothesis of the proposed project is that an expansion of the ATTCT repeat causes the disease by altering the E46 transcript through a repeat size-dependent mechanism. SCA1 0 is one of the newly recognized dominantly inherited ataxias, and its epidemiological, clinical and genetic features have not been fully characterized. Thus, further characterization of the genotype, phenotype, and genotype-phenotype correlation in SCA10 patients needs to be the starting point of this project, and is designated as Specific Aim 1. Accomplishing this Specific Aim should strengthen our hypothesis that the disease-causing mechanism is dependent on the repeat size.
Specific Aim 2 will examine the E46 transcripts in available tissues to look for quantitative changes, aberrantly processed transcripts and abnormal localization of transcripts in SCA10.
Specific Aim 3 will investigate E46 protein functions by analyzing the quantities and isoforms of this protein by western blot, determining the protein localization by immuno-cytochemistry, isolating proteins that interact with the normal and, if detected, aberrant E46 protein products by yeast-two-hybrid and co-immunoprecipitation techniques, and developing E46-deficient cell culture models for cell survival, proliferation and differentiation studies. Data obtained from Specific Aims 2 and 3 will be compared with the expanded repeat size, when applicable. Accomplishing these Specific Aims will provide important insights into understanding the pathogenic consequences of this novel pentanucleotide expansion in SCA10.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS041547-02
Application #
6540440
Study Section
Special Emphasis Panel (ZRG1-BDCN-3 (01))
Program Officer
Gwinn, Katrina
Project Start
2001-05-01
Project End
2002-06-30
Budget Start
2002-05-01
Budget End
2002-06-30
Support Year
2
Fiscal Year
2002
Total Cost
$16,405
Indirect Cost
Name
Baylor College of Medicine
Department
Neurology
Type
Schools of Medicine
DUNS #
074615394
City
Houston
State
TX
Country
United States
Zip Code
77030
McFarland, Karen N; Liu, Jilin; Landrian, Ivette et al. (2015) SMRT Sequencing of Long Tandem Nucleotide Repeats in SCA10 Reveals Unique Insight of Repeat Expansion Structure. PLoS One 10:e0135906
Baizabal-Carvallo, J F; Xia, G; Botros, P et al. (2015) Bolivian kindred with combined spinocerebellar ataxia types 2 and 10. Acta Neurol Scand 132:139-42
McFarland, Karen N; Liu, Jilin; Landrian, Ivette et al. (2014) Repeat interruptions in spinocerebellar ataxia type 10 expansions are strongly associated with epileptic seizures. Neurogenetics 15:59-64
Bushara, Khalaf; Bower, Matthew; Liu, Jilin et al. (2013) Expansion of the Spinocerebellar ataxia type 10 (SCA10) repeat in a patient with Sioux Native American ancestry. PLoS One 8:e81342
Xia, Guangbin; McFarland, Karen N; Wang, Kang et al. (2013) Purkinje cell loss is the major brain pathology of spinocerebellar ataxia type 10. J Neurol Neurosurg Psychiatry 84:1409-11
Moro, Adriana; Munhoz, Renato P; Raskin, Salmo et al. (2013) Acute onset of cerebellar ataxia in a spinocerebellar ataxia type 10 patient after use of steroids. Arq Neuropsiquiatr 71:66
McFarland, Karen N; Liu, Jilin; Landrian, Ivette et al. (2013) Paradoxical effects of repeat interruptions on spinocerebellar ataxia type 10 expansions and repeat instability. Eur J Hum Genet 21:1272-6
White, Misti; Xia, Guangbin; Gao, Rui et al. (2012) Transgenic mice with SCA10 pentanucleotide repeats show motor phenotype and susceptibility to seizure: a toxic RNA gain-of-function model. J Neurosci Res 90:706-14
McFarland, Karen N; Ashizawa, Tetsuo (2012) Transgenic models of spinocerebellar ataxia type 10: modeling a repeat expansion disorder. Genes (Basel) 3:481-91
Moscovich, Mariana; Munhoz, Renato Puppi; Teive, Helio A et al. (2012) Olfactory impairment in familial ataxias. J Neurol Neurosurg Psychiatry 83:970-4

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