Novel point mutations in the steroid sulfatase gene in patients with X-linked ichthyosis: transfection analysis using the mutated genes.

Abstract

X-linked ichthyosis is caused by steroid sulfatase deficiency which results from abnormalities in its coding gene. The majority of X-linked ichthyosis patients ( approximately 90%) have complete or partial deletions of the steroid sulfatase gene. In this study, we examined the mutations of the steroid sulfatase gene in two unrelated X-linked ichthyosis patients without complete deletion of the gene. Polymerase chain reaction-single-strand conformation polymorphism and direct sequencing analyses showed that each patient has a different single base pair substitution within exon 8 encoding the C-terminal half of the steroid sulfatase polypeptide. Both mutations resulted in the transversion of functional amino acids: a G-->C substitution at nucleotide 1344, causing a predicted change of a glycine to an arginine, and a C-->T substitution at nucleotide 1371, causing a change from a glutamine to a stop codon. In vitro steroid sulfatase cDNA expression using site-directed mutagenesis revealed that these mutations are in fact pathogenic and reflect the levels of steroid sulfatase enzyme activities in each of the X-linked ichthyosis patients.

• Authors: N Oyama, M Satoh, K Iwatsuki, F Kaneko
• Journal: The Journal of investigative dermatology (J Invest Dermatol) Vol. 114 Issue 6 Pg. 1195-9 (Jun 2000) ISSN: 0022-202X [Print] United States
• PMID: 10844566 (Publication Type: Journal Article)

Chemical References

• Arylsulfatases
• Steryl-Sulfatase

Topics

• Adult
• Arylsulfatases (genetics)
• Gene Deletion
• Humans
• Ichthyosis (genetics)
• Male
• Middle Aged
• Point Mutation
• Steryl-Sulfatase
• Transfection
• X Chromosome