Figure 1. Fragile X testing. The number of CGG repeats was determined by Tripled Repeat Primed PCR amplification of the 5' untranslated region of the FMR1 gene followed by capillary electrophoresis (AmplideX FMR1 PCR Kit, Asuragen, Austin, TX, USA). (A): Patient with a full mutation, confirming the diagnosis of Fragile X syndrome; (B): Patient with two alleles with 30 and 59 CGG repeats, suggestive of premutation; (C): Patient with two alleles with 30 and 52 CGG repeats, which corresponds to an “intermediate allele” carrier; (D) Patient with two normal alleles with 30 and 40 CGG repeats