title: An unusual case of X-15 translocation: evidence for the presence of an 'activator' region on Xpter of man.
abstract: A case of an X-autosome rearrangement is presented in which part of the Xpter is deleted but the STS and MIC2X loci are retained. The normal X is late replicating in 97/100 lymphocytes and 50/50 fibroblasts examined. It is assumed that the initial X-inactivation in the embryo is random, but that cells with the rearranged X inactivated are selected against because inactivation spreads into the attached autosomal segment. This spreading, through the normally active STS locus, is hypothesised to be caused by deletion of a part of Xpter which is critical for the maintenance of activity of the Xpter region as a whole.
mesh_terms: D002478:Cells, Cultured; D002871:Chromosome Banding; D002874:Chromosome Mapping; D002901:Chromosomes, Human, 13-15; D004303:Dosage Compensation, Genetic; D005260:Female; D005347:Fibroblasts / Q000648:ultrastructure; D005819:Genetic Markers; D006801:Humans; D007621:Karyotyping; D008297:Male; D043266:Steryl-Sulfatase; D013429:Sulfatases / Q000235:genetics; D014178:Translocation, Genetic; D014960:X Chromosome
chemical_list: D005819:Genetic Markers; D013429:Sulfatases; D043266:Steryl-Sulfatase