Genetic tests for the mother showed two normal FMR1 copies in her blood. (A) Genome-wide copy number analysis for the mother, showing no deleted region on the X chromosomes in her blood based on the B allele frequency and log R ratio. (B) FISH using Rp11-161 L9 and Rp11-54I20 detected both the targeted orange signal and the green control signal on the mother’s two X chromosomes, as indicated by the orange arrows. chr(X): normal X chromosome. (C) Sensitive qPCR analysis for FMR1 dosage using three sets of primers within the deleted region showed no significant difference between the mother and a normal female control. Error bars indicate standard deviations. 5′: with primers 5′-F and 5′-R, Exon 7: with primers Exon7-F and Exon7-R, Exon 15: with primers Exon 15-F and Exon 15-R.