FMR1 and fragile X syndrome: Mean FMR1 mRNA assessed by qRT-PCR using the buccal swab showed a mean level of 0.354 ± 0.38 Delta Cq and 0.443 ± 0.54 Delta Cq in FXS participants compared to 1.108 ± 0.85 Delta Cq and 0.772 ± 0.34 Delta Cq for healthy participants at visit 1 and visit 2, respectively.