Regional assignment of the gene locus for steroid sulfatase

Abstract
The gene locus for steroid sulfatase, deficiency of which causes X-linked ichthyosis, is assigned to Xp11→Xpter by analysis of 24 man-Chinese hamster somatic cell hybrids. High steroid sulfatase,activity in a hybrid clone having retained only part of Xq is explained by demonstration of an additional late-replicating human X chromosome. This observation confirms previous evidence for noninactivation of the STS locus.