Unbalanced X/autosomal translocation with inactivation of the normal X chromosome

摘要

A 20-year-old aphasic, severely retarded girl with multiple abnormalities but normal menstruation was studied by fluorescence microscopy, autoradiography, and the G-band-ing method. Autosome material most likely from the long arm of chromosome 8 was translocated onto the short arm of one X chromosome. It was not possible to show loss of X-chromosome material from the translocation chromosome. Autoradiography showed inactivation of the normal X chromosome in all suitable cells. This was in contrast to other observations which showed inactivation of the normal X in balanced X/autosomal translocations but not in the unbalanced translocations.