Screening for intermediate CGG alleles of FMR1 gene in male Iranian patients with Parkinsonism

Male carriers of an expansion of CGG alleles (with 55-200 CGG repeats) in the FMR1 gene are affected with Fragile X-associated tremor/ataxia syndrome (FXTAS). On the other hand, individuals with Parkinson's disease (PD) or Parkinsonism spectrum disorders may have some clinical features that overlap with FXTAS. To investigate the possible association between PD and FMR1 expanded alleles, we screened a total of 154 male PD patients and 190 gender- and age-matched healthy control subjects from Iran. Eleven intermediate allele carriers (7.14 %) were detected among PD patients, compared with three carriers (1.57 %) among the controls (P = 0.01). No pre-mutation carriers were identified. Our results indicate that there is a potential association between FMR1 intermediate expanded alleles and PD.