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The relationship between trinucleotide (CAG) repeat length and clinical features of Huntington's disease


Huntington's disease (HD) is associated with the expansion of a CAG trinucleotide repeat in a novel gene. We have assessed 360 HD individuals from 259 unrelated families and found a highly significant correlation (r = 0.70, p = 10−7) between the age of onset and the repeat length, which accounts for approximately 50% of the variation in the age of onset. Significant associations were also found between repeat length and age of death and onset of other clinical features. Sib pair and parent–child analysis revealed that the CAG repeat demonstrates only mild instability. Affected HD siblings had significant correlations for trinucleotide expansion (r = 0.66, p < 0.001) which was not apparent for affected parent–child pairs.

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Andrew, S., Paul Goldberg, Y., Kremer, B. et al. The relationship between trinucleotide (CAG) repeat length and clinical features of Huntington's disease. Nat Genet 4, 398–403 (1993).

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