Analysis of the STS gene in 40 patients with recessive X-linked ichthyosis: a high frequency of partial deletions in a Spanish population

Background Recessive X-linked ichthyosis (RXLI) (OMIM 308100) is a genodermatosis characterized by polygonal, dark, adherent and mild-to-moderate scales that normally improve during summer. RXLI is caused by a deficiency in steroid sulphatase (STS), whose gene has been located on the X chromosome (locus Xp22.3). Up to 90% of the mutations described in this gene are complete deletions. Objectives Previous reports of partial deletion of STS gene in cases of RXLI prompted us to determine the incidence of these abnormalities in a Spanish population. Methods We have studied exons 1, 5 and 10 of the STS gene by polymerase chain reaction in 40 patients with clinical features of RXLI. Results Our results revealed that 30 patients presented complete deletions (75%) while 10 patients had partial deletions (25%) a rate higher than that reported in the previous studies. Conclusions Amplification of exons 1, 5 and 10 is reliable in screening RXLI in the population studied here. No correlation was found between phenotype and the extent of the deletions. Received: 4 September 2009; Accepted: 14 January 2010