Steroid sulphatase in man: A non inactivated X-locus with partial gene dosage compensation
- Cite this article as:
- Lykkesfeldt, G., Lykkesfeldt, A.E. & Skakkebæk, N.E. Hum Genet (1984) 65: 355. doi:10.1007/BF00291559
Steroid sulphatase (STS) activity was measured with two different steroid substrates in leucocytes from normal human males and females, from females heterozygous for STS deficiency and recessive X-linked ichthyosis, and from individuals with numerical X chromosome aberrations. The results indicate non-inactivation with a partial gene dosage compensation at the STS locus. It is estimated that STS loci on inactive X chromosomes express approximately 45% of the STS activity originating from STS loci on active X chromosomes. It is also demonstrated that 45.XO (Turner syndrome) and 47,XXY (Klinefelter syndrome) individuals have abnormal STS enzyme levels compared with normal women and men, respectively.