TY - JOUR T1 - Two unrelated patients with inversions of the X chromosome and non-specific mental retardation: physical and transcriptional mapping of their common breakpoint region in Xq13.1 JF - Journal of Medical Genetics JO - J Med Genet SP - 754 LP - 758 DO - 10.1136/jmg.36.10.754 VL - 36 IS - 10 AU - Laurent Villard AU - Sylvain Briault AU - Anne-Marie Lossi AU - Christine Paringaux AU - Jérôme Belougne AU - Laurence Colleaux AU - D R Pincus AU - E Woollatt AU - James Lespinasse AU - Arnold Munnich AU - Claude Moraine AU - Michel Fontès AU - Jozef Gecz Y1 - 1999/10/01 UR - http://jmg.bmj.com/content/36/10/754.abstract N2 - Two unrelated mildly retarded males with inversions of the X chromosome and non-specific mental retardation (MRX) are described. Case 1 has a pericentric inversion 46,Y,inv(X)(p11.1q13.1) and case 2 a paracentric inversion 46,Y,inv(X) (q13.1q28). Both male patients have severe learning difficulties. The same chromosomal abnormalities were found in their mothers who are intellectually normal. Fluorescence in situ hybridisation mapping showed a common area of breakage of each of the inverted chromosomes in Xq13.1 near DXS131 and DXS162. A detailed long range restriction map of the breakpoint region was constructed using YAC, PAC, and cosmid clones. We show that the two inverted chromosomes break within a short 250 kb region. Moreover, a group of ESTs corresponding to an as yet uncharacterised gene was mapped to the same critical interval. We hypothesise that the common inversion breakpoint region of the two cases in Xq13.1 may contain a new MRX gene. ER -