title: Comparative studies of the CAG repeats in the spinocerebellar ataxia type 1 (SCA1) gene.
abstract: The CAG repeat tract at the autosomal dominant spinocerebellar ataxia type 1 (SCA1) locus was analyzed in SCA1 families and French-Acadian, African-American, Caucasian, Greenland Inuit, and Thai populations. The normal alleles had 9-37 repeats, whereas disease alleles contained 44-64 repeats. The CAG repeat tract contained one or two CAT interruptions in 44 of 47 normal human chromosomes and in all five chimpanzees examined. In contrast, no CAT interruptions were found in Old World monkeys or expanded human alleles. The number and positions of CAT interruptions may be important in stabilizing CAG repeat tracts in normal chromosomes. At least five codons occupy the region corresponding to the polyglutamine tract at the SCA1 locus in mice, rats, and other rodents. They comprise three or four CCN (coding for proline) in addition to one or two CAG repeats.
authors.affiliation: Department of Biometry and Genetics, Louisiana State University Medical Center, New Orleans 70112, USA.
authors.forename: P
authors.initials: P
authors.lastname: Limprasert
authors.forename: N
authors.initials: N
authors.lastname: Nouri
authors.forename: C
authors.initials: C
authors.lastname: Nopparatana
authors.forename: P L
authors.initials: PL
authors.lastname: Deininger
authors.forename: B J
authors.initials: BJ
authors.lastname: Keats
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000067696:Ataxin-1; D000067528:Ataxins; D001483:Base Sequence; D016664:Cercocebus; D005849:Gerbillinae; D006168:Guinea Pigs; D006801:Humans; D008251:Macaca; D051379:Mice; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics*; D009687:Nuclear Proteins / Q000235:genetics*; D002679:Pan troglodytes; D010542:Peromyscus; D016133:Polymerase Chain Reaction; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D012589:Sciuridae; D013132:Spinocerebellar Degenerations / Q000209:etiology / Q000235:genetics*; D018911:Trinucleotide Repeats / Q000235:genetics*
chemical_list: C000593749:ATXN1 protein, human; D000067696:Ataxin-1; D000067528:Ataxins; C000593750:Atxn1 protein, mouse; C000593751:Atxn1 protein, rat; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins