(CAG)n loci as genetic modifiers of age at onset in patients with spinocerebellar ataxia type 1 from mainland China.

By using interaction analyses, TBP, ATN1 and HTT were determined to have modifying effects. Our study revealed that differences in modulation may be due to ethnic and geographic diversity across different populations. Furthermore, the variability of AAO was not completely explained by the genetic modifiers examined here, suggesting that other genetic or environmental factors are involved in these diseases.