Intergenerational instability of the CAG repeat of the gene for Machado-Joseph disease (MJD1) is affected by the genotype of the normal chromosome: Implications for the molecular mechanisms of the instability of the CAG repeat
Machado-Joseph disease (MJD) is an autosomal dominant neurodegenerative disorder caused by unstable expansion of a CAG repeat in the MJD1 gene at 14q32.1. To identify elements affecting the intergenerational instability of the CAG repeat, we investigated whether the CGG/GGG polymorphism at the 3' end of the CAG repeat affects intergenerational instability of the CAG repeat The [expanded (CAG)n-CGG]/[normal (CAG)n-GGG] haplotypes were found to result in significantly greater instability of the CAG repeat compared to the [expanded (CAG)n-CGG]/[normal (CAG)n-CGG] or [expanded (CAG)nGGG]/[normal (CAG)n-GGG] haplotypes. Multiple stepwise logistic regression analysis revealed that the relative risk for a large intergenerational change in the number of CAG repeat units (<-2 or >2) is 7.7-fold (95% CI: 2.5-23.9) higher in the case of paternal transmission than in that of maternal transmission and 7.4-fold (95% CI: 2.4-23.3) higher in the case of transmission from a parent with the [expanded (CAG)n-CGG]/[normal (CAG)n-GGG] haplotypes than in that of transmission from a parent with the [expanded (CAG)n-CGG]/[normal (CAG)n-CGG] or [expanded (CAG)n-GGG]/[normal (CAG)n-GGG] haplotypes. The combination of paternal transmission and the [expanded (CAG)n-CGG]/[normal (CAG)n-GGG] haplotypes resulted in a 75.2-fold (95% CI: 9.0-625.0) increase in the relative risk compared with that of maternal transmission and the [expanded (CAG)n-CGG]/[normal (CAG)n-CGG] or [expanded (CAG)n-GGG]/[normal (CAG)n-GGG] haplotypes. The results suggest that an inter-allelic interaction is involved in the intergenerational instability of the expanded CAG repeat.
Igarashi S,Takiyama Y,Cancel G,et al.Intergenerational instability of the CAG repeat of the gene for Machado-Joseph disease (MJD1) is affected by the genotype of the normal chromosome: Implications for the molecular mechanisms of the instability of the CAG repeat[J].HUMAN MOLECULAR GENETICS.1996,5(7):923-932.doi:10.1093/hmg/5.7.923.
APA：
Igarashi, S,Takiyama, Y,Cancel, G,Rogaeva, EA,Sasaki, H...&Tsuji, S.(1996).Intergenerational instability of the CAG repeat of the gene for Machado-Joseph disease (MJD1) is affected by the genotype of the normal chromosome: Implications for the molecular mechanisms of the instability of the CAG repeat.HUMAN MOLECULAR GENETICS,5,(7)
MLA：
Igarashi, S,et al."Intergenerational instability of the CAG repeat of the gene for Machado-Joseph disease (MJD1) is affected by the genotype of the normal chromosome: Implications for the molecular mechanisms of the instability of the CAG repeat".HUMAN MOLECULAR GENETICS 5..7(1996):923-932
