[Somatic mosaicism of CAG repeats size in the nervous system of dentatorubral-pallidoluysian atrophy (DRPLA)].

The somatic mosaicism of CAG repeat expansion in the neural tissues of a dentatorubral-pallidoluysian atrophy (DRPLA) was reviewed. The size of the major bands of the expanded allele was significantly smaller in the cerebellar cortex, however no significant difference was recognized in other regions of neuronal tissues. This showed that severity of neuropathological involvement in DRPLA is not parallel to the size of the expanded allele, indicating somatic mosaicism doesn't explain the selective neurodegeneration in DRPLA. The mechanism underlying the somatic mosaicism remains unknown. However, somatic CAG instability, cell division and some tissue specific factors may closely relate to the occurrence of the somatic mosaicism.