A comparative study on steroid sulfatase and arylsulfatase C in fibroblast clones from 45,X/47,XXX and 69,XXY

Steroid sulfatase (STS) and arylsulfatase C ( ARSC ) were studied in fibroblast clones from a 45,X/47,XXX mosaic and from a 69,XXY triploidy with one or two active X chromosomes. The comparison of the 47,XXX with 45,X clones showed an incomplete gene dosage effect (1.8 for STS and 2.0 for ARSC ). This was not the case for the triploid clones with different X-inactivation patterns. These results confirm previous reports on the non-inactivation of the STS gene, and establish X linkage and non-inactivation for the ARSC gene as well.