title: Large expansion of the ATTCT pentanucleotide repeat in spinocerebellar ataxia type 10.
abstract: Spinocerebellar ataxia type 10 (SCA10; MIM 603516; refs 1,2) is an autosomal dominant disorder characterized by cerebellar ataxia and seizures. The gene SCA10 maps to a 3.8-cM interval on human chromosome 22q13-qter (refs 1,2). Because several other SCA subtypes show trinucleotide repeat expansions, we examined microsatellites in this region. We found an expansion of a pentanucleotide (ATTCT) repeat in intron 9 of SCA10 in all patients in five Mexican SCA10 families. There was an inverse correlation between the expansion size, up to 22.5 kb larger than the normal allele, and the age of onset (r2=0.34, P=0.018). Analysis of 562 chromosomes from unaffected individuals of various ethnic origins (including 242 chromosomes from Mexican persons) showed a range of 10 to 22 ATTCT repeats with no evidence of expansions. Our data indicate that the new SCA10 intronic ATTCT pentanucleotide repeat in SCA10 patients is unstable and represents the largest microsatellite expansion found so far in the human genome.
authors.affiliation: Department of Neurology, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: T
authors.initials: T
authors.lastname: Matsuura
authors.forename: T
authors.initials: T
authors.lastname: Yamagata
authors.forename: D L
authors.initials: DL
authors.lastname: Burgess
authors.forename: A
authors.initials: A
authors.lastname: Rasmussen
authors.forename: R P
authors.initials: RP
authors.lastname: Grewal
authors.forename: K
authors.initials: K
authors.lastname: Watase
authors.forename: M
authors.initials: M
authors.lastname: Khajavi
authors.forename: A E
authors.initials: AE
authors.lastname: McCall
authors.forename: C F
authors.initials: CF
authors.lastname: Davis
authors.forename: L
authors.initials: L
authors.lastname: Zu
authors.forename: M
authors.initials: M
authors.lastname: Achari
authors.forename: S M
authors.initials: SM
authors.lastname: Pulst
authors.forename: E
authors.initials: E
authors.lastname: Alonso
authors.forename: J L
authors.initials: JL
authors.lastname: Noebels
authors.forename: D L
authors.initials: DL
authors.lastname: Nelson
authors.forename: H Y
authors.initials: HY
authors.lastname: Zoghbi
authors.forename: T
authors.initials: T
authors.lastname: Ashizawa
mesh_terms: D000818:Animals; D044466:Asian People / Q000235:genetics; D001921:Brain / Q000378:metabolism / Q000473:pathology; D002874:Chromosome Mapping; D002892:Chromosomes, Human, Pair 22; D004247:DNA / Q000097:blood / Q000737:chemistry / Q000235:genetics*; D004827:Epilepsy / Q000235:genetics / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D017058:Mexican Americans / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D010375:Pedigree; D011110:Polymorphism, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D020754:Spinocerebellar Ataxias / Q000235:genetics* / Q000473:pathology; D014481:United States; D044465:White People / Q000235:genetics
chemical_list: D004247:DNA