Correlation between magnitude of CAG repeat length alterations and length of the paternal repeat in paternally inherited Huntington's disease |
| |
Authors: | Anne Nø rremø lle,Sven Asger Sø rensen ,Kirsten Fenger,Lis Hasholt |
| |
Affiliation: | Institute of Medical Biochemistry and Genetics, Laboratory of Medical Genetics, University of Copenhagen, Copenhagen, Denmark |
| |
Abstract: | An increasing number of diseases are being found to be due to elongation of specific trinucleotide repeat sequences. Inverse correlation between the age at onset and the length of the repeat has been found in most of these. The elongated CAG repeat causing Huntington's disease is highly unstable when inherited from an affected father. In this study we found an average parent-to-offspring difference of +0.08 repeat units in maternally inherited repeats, significantly less than the average difference of +2.92 repeat units with paternal transmission. Large repeat expansions, of more than 5 repeat units, were seen only in paternally inherited cases. With paternal transmission the magnitude of repeat length alterations was directly correlated to increasing paternal repeat length. Increasing variation in repeat length among siblings was correlated to increasing average repeat length in the sibship in both maternally and paternally inherited HD. Comparison of the magnitude of repeat length alterations to parental age at the time of birth of the offspring showed no correlation. |
| |
Keywords: | elongated trinucleotide repeat Huntington's disease parental repeat length repeat length alterations sex of affected parent |
|
|