As the STS gene escapes X-inactivation, female carriers of XLI-associated genetic mutations have reduced STS expression/activity relative to non-carrier females, and could manifest similar behavioural phenotypes to males with XLI.
X-linked ichthyosis (XLI) is a recessive keratinization condition caused by deficient activity of steroid-sulfatase due to mutations in steroid sulfatase (STS) gene located on the X chromosome.
CNV-Seq analysis of the maternal white blood cell DNA archived from the original two NIPT blood samples identified small CNVs spanning the STS gene, which is associated with X-linked ichthyosis.
Further studies are required to determine whether the STS gene or the co-deleted flanking sequences are the cause of renal disease associated with XLI.
Additional samples were collected from the forearms of subjects with ichthyosis vulgaris (filaggrin (FLG) deficiency), recessive X-linked ichthyosis (steroid sulfatase (STS) deficiency) and autosomal recessive congenital ichthyosis type lamellar ichthyosis (transglutaminase 1 (TGM1) deficiency).
Xp22.3 interstitial deletion: a recognizable chromosomal abnormality encompassing VCX3A and STS genes in a patient with X-linked ichthyosis and mental retardation.
Although deletion of STS in males is known to cause X-linked ichthyosis, the clinical significance of STS copy gains is less clear, with the duplication reported in individuals with abnormal phenotypes and normal relatives.
An unusually severe XLI phenotype in addition to eczema and mild childhood asthma was investigated in a female Indian patient by fluorescent in situ hybridization (FISH) for the common STS gene deletion.
We report the first case of a patient with both XLI and DEB in whom a partial deletion of the STS gene and a recessive point mutation in COL7A1 were demonstrated.
Egyptian males complaining of X-linked ichthyosis were clinically examined, evaluating pedigree analysis of the family, cytogenetic studies using G-banding technique and FISH using locus specific probe for steroid sulfatase (STS) gene which is located at chromosome Xp22.3.
The patient had undetectable levels of STS activity when compared with normal control (0.00 pmol mg(-1) protein h(-1)) which confirmed the diagnosis of X-linked ichthyosis (XLI) .