Degeneration decades before disease onset

Abstract

Somatic CAG repeat expansion is associated with neurodegeneration decades before clinical onset of Huntington disease (HD), a new study has shown. The work involved 57 people with expansions in the HD gene whose clinical onset was predicted to be around 23 years away. Even though there was no clinical impairment at baseline, cerebrospinal fluid and imaging markers indicated early neurodegeneration. Subsequent increases in somatic CAG repeat expansion over time were associated with greater atrophy, providing insight into the mechanisms of the earliest neurodegeneration.