The 5′-UTR of the FMR1 gene contains a stretch of CGG repeats that causes a series of pathological conditions when exceeding 54 repeats, although there is increasing evidence of an association between the “gray zone”, ranging from 45 up to 54 triplet copies (which forms an unstable FMR1 allele that can be expanded in successive generations [2]) with atypical parkinsonism [3]. The gene discussed is FMR1; the disease is Parkinson disease.