Identification of novel variation in introns three and four of the iduronate-2-sulfatase gene in patients with mucopolysaccharidosis type II

To identify and analyze mutations that occur in introns of the iduronate-2-sulfatase (IDS) gene of patients with mucopolysaccharidosis type II (MPS II) in Indonesia. DNA samples from 6 patients with MPS II and 49 normal individuals were analyzed with direct sequencing of introns three and four. A novel variant was found at the site c.419-132del in intron three and three variants were found at c.507 + 26G>A, c.507 + 29G>A, and c.507 + 63T>G in intron four of the IDS gene. These variations occur in the non-splicing site of the IDS gene in patients with MPS II and normal individuals and do not affect the structure of the IDS gene. Alterations which occur in one site of intron three and three sites of intron four are new variations of the IDS gene found in Indonesian patients. This finding suggests that the IDS gene may show variation in other sites that could be associated with MPS II. These mutations can enrich the single nucleotide polymorphism database for the IDS gene globally. Further genotype studies should be performed to obtain a full profile of the IDS gene in patients with MPS II in Indonesia.