Electropherograms showing the profile of the STR-markers throughout the FMR1 gene and its surrounding regions. Each lane shows the peaks obtained for each marker after the application of the specific multiplex fluorescent PCR method for FXS in a couple (lanes 1 and 2) and in the blastomeres biopsied from two of the embryos of their PGD-cycle (lanes 3 and 4). Each peak corresponds to the PCR product amplification of a marker, whose size depends on the specific number of repeats (the more the repeats the larger the PCR product). The sizes for each marker in each lane are also indicated with numbers. The sizes of the specific combination of alleles linked to the disease, which was identified by a previous informativity testing in the context of the family, are shown in italic and underlined characters.