1. Xq28 intrachromosomal duplications were identified in female II2 (daughter) and I2 (mother) by SNP array, qPCR, and FISH analyses
We detected I1, I2, and II2 by Affymetrix CytoScan HD Array. It showed a 437 kb duplication on the Xq28 region (chrX:153858452-154332213 in the genome build GRCh38) and 284 kb duplication on the Xq27.3 region (chrX:144988272-145271978: in the genome build GRCh38) in female II2 and her mother I2 (Figure 1B), which demonstrated that the Xq28 and Xq27.3 duplications were maternally inherited. The Xq28 region contains 13 Online Mendelian Inheritance in Man (OMIM) genes (including MECP2, IRAK1, L1CAM, NAA10, andHCFC1 ). We also performed qPCR to verify the results, and one copy of the gene dosages of MECP2 and IRAK1 were detected in male I1, whereas two copies were detected in the normal control female, and three copies were detected in I2 and II2 (Figures 1C, D). FISH analysis on metaphase chromosomes of females I2 and II2 revealed signals for the MECP2 -containing probe RP11-119A22 only at Xq28, which indicates that the Xq28 duplications were tandem repeats that had not integrated elsewhere in the genome (Figures 1E, F).