Determination of the organisation of coding sequences within the iduronate sulphate sulphatase (IDS) gene

The structure of the gene coding for iduronate sulphate sulphatase (IDS) has been determined. We have used exon to exon and vectorette PCR to identify 9 exons within the IDS gene and to characterise the surrounding intron sequences. The results of this study will be useful for the complete analysis of many mutations giving rise to Hunter syndrome. IDS is the first member of the group of lysosomal non-arylsulphatase genes for which the gene structure has been determined. It bears no relationship to the exon organisation of steroid sulphatase, despite the homology between these two proteins. This suggests that the division of the sulphatases into the two subgroups on the basis of substrate specificity is also reflected at the level of gene structure.