Non-inactivation of an x-chromosome locus in man.
Cloned fibroblasts from women heterozygous for X-linked ichthyosis (steroid sulfatase deficiency) were examined to see whether or not this locus is subject to X-inactivation. Of 103 clones examined, all had normal levels of steroid sulfatase activity. Two of the women studied were also heterozygous for glucose-6-phosphate dehydrogenase deficiency. This allowed the demonstration that both X chromosomes were represented as the active X in various clones and that selection did not account for these findings. Thus, the steroid sulfatase locus, like the Xga locus to which it is linked, appears to escape X-inactivation in man.
D003687:Dehydroepiandrosterone; D005260:Female; D008040:Genetic Linkage; D006801:Humans; D007057:Ichthyosis / Q000235:genetics*; D010375:Pedigree; D012730:Sex Chromosomes / Q000502:physiology*; D013429:Sulfatases / Q000172:deficiency* / Q000235:genetics; D014960:X Chromosome / Q000502:physiology*
D003687:Dehydroepiandrosterone; D013429:Sulfatases