Array-MLPA analysis of chromosome X monosomy patients with unknown marker chromosomes. (A) Strong hybridization signals for TSPY were detected in sample B6. (B) Positive signals for RBMY and TSPY were found in sample B7. (C) PCR analysis of RBMY, SRY and TSPY detects the unknown marker chromosome detected with G-banding analysis. (D) The unknown marker chromosome in the sample B6 was derived from chromosome Y.