Anticipation and intergenerational repeat instability in spinocerebellar ataxia type 17
2007; Wiley; Volume: 61; Issue: 6 Linguagem: Inglês
10.1002/ana.21139
ISSN1531-8249
AutoresAstrid Rasmussen, Irene De Biase, Marcela Fragoso‐Benítez, Marco Antonio Macías‐Flores, Petra Yescas, Adriana Ochoa, Tetsuo Ashizawa, María Elisa Alonso, Sanjay I. Bidichandani,
Tópico(s)DNA Repair Mechanisms
ResumoAbstract Spinocerebellar ataxia type 17 (SCA17) is caused by expansion of a CAG/CAA repeat in the TBP gene. Most pathogenic alleles are interrupted and are stably transmitted from parent to offspring without anticipation. We identified three SCA17 families with expansion of uninterrupted alleles, thus greatly increasing the number of known intergenerational transmissions of such alleles. We found that uninterrupted SCA17 alleles are unstable, associated with anticipation, and show a paternal expansion bias that increases with age. Even small increments in repeat length resulted in inordinate increases in anticipation. Anticipation was also associated with childhood presentation. Sequencing of all SCA17 alleles is required for effective genetic counseling. Ann Neurol 2007
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