A STUDY OF THE STEROID SULFATASE GENE IN FAMILIES WITH X-LINKED ICHTHYOSIS USING POLYMERASE CHAIN-REACTION

We have studied the steroid sulfatase (STS) gene in three Japanese fam ilies with X-linked ichthyosis (XLI), using polymerase chain reaction (PCR), PCR was performed using three sets of intraexonic primers cover ing exons 1, 5 and 10. In affected individuals from two of the familie s, DNA was not amplified in any of the three exons, suggesting that XL I in these families was due to the complete deletion of the STS gene. In affected individuals in the remaining family, DNA was amplified in predicted sizes in exons 1 and 5, but not in exon 10, suggesting that XLI in this family was due to partial deletion of the STS gene includi ng exon 10. These results suggested that STS gene deficiency is hetero geneous in Japanese families with XLI. PCR is useful for the rapid dia gnosis of XLI, the differentiation of XLI from ichthyosis vulgaris, an d genetic counseling of XLI families. The PCR method was not applicabl e for carrier detection.