A novel long and unstable CAG/CTG trinucleotide repeat on chromosome 17q.

Using the direct identification of repeat expansion and cloning technique, we cloned a novel long CAG/CTG trinucleotide repeat on chromosome 17. Using radiation hybrid panels, the CAG/CTG repeat was mapped to chromosome 17q. The CAG/CTG repeat is highly polymorphic, with a heterozygosity of 85%, and exhibits a bimodal distribution (allele S, 10-26 repeat units, and allele L, 50-92 repeat units). The CAG/CTG repeat of allele L exhibited intergenerational instabilities, which are more prominent in maternal transmission than in paternal transmission. Analyses of Northern blot and RT-PCR indicate that the repeat is transcribed. Although the size of the CAG/CTG repeat of allele L is within the range of the expanded CAG repeat of disease-causing genes, we did not detect any association of allele L with various neurodegenerative diseases, including frontotemporal dementia and parkinsonism, mapped to 17q21-q23.

[1]  Mika Nakamoto,et al.  A CAG/CTG expansion in the normal population , 1997, Nature Genetics.

[2]  F. McMahon,et al.  A novel, heritable, expanding CTG repeat in an intron of the SEF2-1 gene on chromosome 18q21.1. , 1997, Human molecular genetics.

[3]  Y. Agid,et al.  Cloning of the SCA7 gene reveals a highly unstable CAG repeat expansion , 1997, Nature Genetics.

[4]  N L Foster,et al.  Frontotemporal dementia and parkinsonism linked to chromosome 17: A consensus conference , 1997, Annals of neurology.

[5]  J. Mandel Breaking the rule of three , 1997, Nature.

[6]  S. M. Sumi,et al.  Chromosome 17 and hereditary dementia , 1997, Neurology.

[7]  K. Kidd,et al.  Survey of maximum CTG/CAG repeat lengths in humans and non-human primates: total genome scan in populations using the Repeat Expansion Detection method. , 1997, Human molecular genetics.

[8]  M. Pericak-Vance,et al.  Linkage of frontotemporal dementia to chromosome 17: clinical and neuropathological characterization of phenotype. , 1996, American journal of human genetics.

[9]  S. Tsuji,et al.  Identification of the spinocerebellar ataxia type 2 gene using a direct identification of repeat expansion and cloning technique, DIRECT , 1996, Nature Genetics.

[10]  S. Tsuji Unstable expansion of triplet repeats as a new disease mechanism for neurodegenerative diseases , 1996, Japanese Journal of Human Genetics.

[11]  G. Gyapay,et al.  A radiation hybrid map of the human genome. , 1996, Human molecular genetics.

[12]  K. Fischbeck,et al.  Trinucleotide repeats in neurogenetic disorders. , 1996, Annual review of neuroscience.

[13]  G. Pals,et al.  Localization of the gene for rapidly progressive autosomal dominant parkinsonism and dementia with pallido-ponto-nigral degeneration to chromosome 17q21. , 1996, Human molecular genetics.

[14]  J. Weissenbach,et al.  Evidence for inter-generational instability in the CAG repeat in the MJD1 gene and for conserved haplotypes at flanking markers amongst Japanese and Caucasian subjects with Machado-Joseph disease. , 1995, Human molecular genetics.

[15]  K. Wilhelmsen,et al.  Localization of disinhibition-dementia-parkinsonism-amyotrophy complex to 17q21-22. , 1994, American journal of human genetics.

[16]  O. Onodera,et al.  Unstable expansion of CAG repeat in hereditary dentatorubral–pallidoluysian atrophy (DRPLA) , 1994, Nature Genetics.

[17]  T. Hudson,et al.  Direct detection of novel expanded trinucleotide repeats in the human genome , 1993, Nature Genetics.

[18]  Manish S. Shah,et al.  A novel gene containing a trinucleotide repeat that is expanded and unstable on Huntington's disease chromosomes , 1993, Cell.

[19]  H. Zoghbi,et al.  Evidence for a mechanism predisposing to intergenerational CAG repeat instability in spinocerebellar ataxia type I , 1993, Nature Genetics.

[20]  R. Myers,et al.  Radiation hybrid mapping: a somatic cell genetic method for constructing high-resolution maps of mammalian chromosomes. , 1990, Science.

[21]  A. Feinberg,et al.  A technique for radiolabeling DNA restriction endonuclease fragments to high specific activity. , 1983, Analytical biochemistry.

[22]  W. Rutter,et al.  Isolation of biologically active ribonucleic acid from sources enriched in ribonuclease. , 1979, Biochemistry.