title: Analysis of SCA8, SCA10, SCA12, SCA17 and SCA19 in patients with unknown spinocerebellar ataxia: a Thai multicentre study.
abstract: BACKGROUND
  About 50 % of Thai patients with adult-onset spinocerebellar ataxia (SCA) was Machado-Joseph disease (MJD), SCA1, SCA2 and SCA6. The author investigated further on less common SCAs in the patients without any known mutations.
  
  
  METHODS
  DNA samples of 82 index patients who were genetically excluded MJD, SCA1, SCA2, SCA6, SCA7 and dentatorubro-pallidoluysian atrophy (DRPLA) were examined. Analysis of SCA8, SCA10, SCA12, SCA17 and SCA19 genes were comprehensively performed. Normal range of trinucleotide repeat expansion sizes of TATA-box-binding protein gene (TBP) were also determined in 374 control subjects.
  
  
  RESULTS
  Eight patients carried ≥42 CAG/CAA repeat allele in the TBP consistent with SCA17. The pathological repeat alleles ranged from 42 to 57 repeats. All patients had significant degree of cognitive dysfunction. Other non-ataxic phenotypes comprised of parkinsonism, chorea, dystonia and myoclonus. A sporadic patient carried a heterozygous 41-repeat allele developed chronic progressive cerebellar degeneration commenced at the age of 28 years. Whilst, 2 % of the control subjects (8/374) carried the 41-repeat allele. Five of the carriers were re-examined, and revealed that four of them had parkinsonism and/or cognitive impairment without cerebellar signs. Analysis of other types of SCAs was all negative.
  
  
  CONCLUSIONS
  This is the first study of SCA8, SCA10, SCA12, SCA17 and SCA19 in Thais. SCA17 appears to be an important cause of ataxia in Thailand. Although, the pathological cut-off point of the TBP repeat allele remains unclear, the finding suggests that the 41-repeat may be a pathological allele resulting late-onset or mild phenotype. Apart from ataxia, cognitive impairment and parkinsonism may be clinical presentations in these carriers.
authors.affiliation: Division of Neurology, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand. lulin.cho@mahidol.ac.th.|Research Center, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand. lulin.cho@mahidol.ac.th.
authors.forename: Lulin
authors.initials: L
authors.lastname: Choubtum
authors.affiliation: Division of Neurology, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand. pirada.wit@mahidol.ac.th.
authors.forename: Pirada
authors.initials: P
authors.lastname: Witoonpanich
authors.affiliation: Department of Neurology, Prasat Neurological Institute, Bangkok, Thailand. suchathanc@yahoo.com.
authors.forename: Suchat
authors.initials: S
authors.lastname: Hanchaiphiboolkul
authors.affiliation: Chulalongkorn Center of Excellence on Parkinson Disease and Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, 10330, Thailand. rbh@chulapd.org.
authors.forename: Roongroj
authors.initials: R
authors.lastname: Bhidayasiri
authors.affiliation: Chulalongkorn Center of Excellence on Parkinson Disease and Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, 10330, Thailand. oji@chulapd.org.
authors.forename: Onanong
authors.initials: O
authors.lastname: Jitkritsadakul
authors.affiliation: Division of Medicine, Bhumibol Adulyadej Hospital, Bangkok, Thailand. sunsaneekaew@yahoo.com.
authors.forename: Sunsanee
authors.initials: S
authors.lastname: Pongpakdee
authors.affiliation: Division of Neurology, Department of Medicine, Buriram Hospital, Buriram, Thailand. suppachok2011@gmail.com.
authors.forename: Suppachok
authors.initials: S
authors.lastname: Wetchaphanphesat
authors.affiliation: Division of Neurology, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand. pairoj.boo@mahidol.ac.th.
authors.forename: Pairoj
authors.initials: P
authors.lastname: Boonkongchuen
authors.affiliation: Division of Neurology, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand. teeratorn.pul@mahidol.ac.th.
authors.forename: Teeratorn
authors.initials: T
authors.lastname: Pulkes
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D044466:Asian People / Q000235:genetics; D016022:Case-Control Studies; D042622:DNA Repeat Expansion / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020754:Spinocerebellar Ataxias / Q000235:genetics*; D013132:Spinocerebellar Degenerations / Q000235:genetics; D035181:TATA-Box Binding Protein / Q000235:genetics; D013785:Thailand; D019680:Trinucleotide Repeat Expansion; D055815:Young Adult
chemical_list: D035181:TATA-Box Binding Protein