Somatic and gonadal mosaicism of the Huntington disease gene CAG repeat in brain and sperm

  title={Somatic and gonadal mosaicism of the Huntington disease gene CAG repeat in brain and sperm},
  author={H{\aa}kan Telenius and B Kremer and Yigal Paul Goldberg and Jane Theilmann and Susan E. Andrew and Jutta Zeisler and Shelin Adam and Cheryl R. Greenberg and Elizabeth J. Ives and Lorne A Clarke and Michael R. Hayden},
  journal={Nature Genetics},
Huntington disease is associated with an unstable and expanded (CAG) trinucleotide repeat. We have analysed the CAG expansion in different tissues from 12 affected individuals. All tissues examined were found to display some repeat mosaicism, with the greatest levels detected in brain and sperm. Regions within the brain showing most obvious neuropathology, such as the basal ganglia and the cerebral cortex, displayed the greatest mosaicism, whereas the cerebellar cortex, which is seldom involved… 

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Somatic mosaicism for Friedreich's ataxia GAA triplet repeat expansions in the central nervous system

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Gametic and somatic tissue–specific heterogeneity of the expanded SCA1 CAG repeat in spinocerebellar ataxia type 1

The differences in SCA1 allele heterogeneity between sperm and blood and within the brain parallels the findings in Huntington disease, suggesting that both disorders share a common mechanism for tissue–specific instability.



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The data indicate that the developmental timing of repeat instability appears to differ between HD and fragile X syndrome, and that the fundamental mechanisms leading to repeat expansion may therefore be distinct.

Mitotic stability and meiotic variability of the (CAG)n repeat in the Huntington disease gene.

The length variation of the repeat in 513 non-HD chromosomes from normal individuals and HD patients showing 23 alleles with 11 to 33 repeats is demonstrated, indicating the repeat number in the DNA of blood lymphocytes is probably representative of all tissues in a patient.

Trinucleotide repeat length instability and age of onset in Huntington's disease

The initial observation of an expanded and unstable trinucleotide repeat in the Huntington's disease gene has now been confirmed and extended in 150 independent Huntington’s disease families and the analysis of the length and instability of individual repeats in members of these families has profound implications for presymptomatic diagnosis.

Expansion of an unstable trinucleotide CAG repeat in spinocerebellar ataxia type 1

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De novo expansion of a (CAG)n repeat in sporadic Huntington's disease

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Trinucleotide repeat elongation in the Huntingtin gene in Huntington disease patients from 71 Danish families.

Investigation of the CAG repeat in the Huntingtin gene in 71 unrelated Danish patients with Huntington's Disease found repeat lengths of 39 to 70 repeat units in contrast to 9 to 30 CAG's on normal chromosomes.

Molecular analysis of new mutations for Huntington's disease: intermediate alleles and sex of origin effects

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Unstable expansion of CAG repeat in hereditary dentatorubral–pallidoluysian atrophy (DRPLA)

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