HGNC Approved Gene Symbol: IDS
SNOMEDCT: 5667009, 70737009, 73146005; ICD10CM: E76.1;
Cytogenetic location: Xq28 Genomic coordinates (GRCh38): X:149,476,988-149,505,306 (from NCBI)
| Location | Phenotype |
Phenotype MIM number |
Inheritance |
Phenotype mapping key |
|---|---|---|---|---|
| Xq28 | Mucopolysaccharidosis II | 309900 | X-linked recessive | 3 |
Iduronate 2-sulfatase (EC 3.1.6.13) is involved in the lysosomal degradation of the glycosaminoglycans heparan sulfate and dermatan sulfate (Bielicki et al., 1990).
DiNatale and Ronsisvalle (1981) identified 2 forms of iduronate sulfatase from human placenta and Bielicki et al. (1990) purified 2 major forms with molecular masses of 42 kD and 14 kD from human liver.
Wilson et al. (1990) isolated and sequenced a 2.3-kb cDNA clone coding for the entire sequence of human IDS from an endothelial cell cDNA library. Analysis of the deduced 550-amino acid precursor indicated that IDS has a 25-amino acid amino-terminal signal sequence, followed by 8 amino acids that are removed from the proprotein. An internal proteolytic cleavage occurs to produce the mature 42- and 14-kD polypeptides observed in liver, kidney, lung, and placenta. A strong sequence homology was found with human arylsulfatases A, B, and C, and human glucosamine-6-sulfatase. Northern blot analysis detected 3 major RNA species (5.7, 5.4, and 2.1 kb) and 1 minor species (1.4 kb).
Malmgren et al. (1995) identified a 1.4-kb transcript and suggested that it may encode an IDS-like enzyme. The predicted protein is identical to the previously described enzyme, except for the absence of a 207-amino acid COOH-terminal domain, which is replaced by 7 amino acids.
Flomen et al. (1993) determined that the IDS gene contains 9 exons (designated A to I). They characterized the intron sequences surrounding the 9 exons. They found that the IDS gene bears no relationship to the exon organization of steroid sulfatase (300747), despite the homology between these 2 proteins. This suggested that the division of the sulfatases into 2 subgroups on the basis of substrate specificity is also reflected at the level of gene structure.
Wilson et al. (1993) reported the complete sequence of the IDS gene, which spans approximately 24 kb. The potential promoter for IDS lacks a TATA box but contains GC box consensus sequences, consistent with its role as a housekeeping gene.
Wilson et al. (1991) used an IDS cDNA clone to localize the gene to Xq28, distal to the fragile X site.
Faust et al. (1992) and Daniele et al. (1993) demonstrated that the homologous Ids gene in the mouse occupies the same position on the X chromosome in relation to the FMR1 (309550), F9 (306900), and GABRA3 (305660) genes.
Pseudogene
Bondeson et al. (1995, 1995) identified a second IDS gene (designated IDS2 by them) located within 90 kb telomeric of the IDS gene. They showed that this region is involved in a recombination event with the primary IDS gene in about 13% of patients with the Hunter syndrome.
Wilson et al. (1991) found a deletion or gene rearrangement in 7 of 23 patients with mucopolysaccharidosis type II (Hunter syndrome; 309900) of Australian and British origin. In 2 of 14 unrelated German MPS II patients, structural alteration of the IDS gene was found by Southern analysis using an IDS cDNA clone as a probe. In one of these patients, a severely affected male, no Southern fragments were detected.
Palmieri et al. (1992) isolated a 1.2-Mb YAC contig spanning the IDS gene. Several putative CpG islands were identified in the region, suggesting the presence of other genes. Southern analysis of DNA from 25 unrelated Italian MPS II patients uncovered 4 with deletions or rearrangements in the IDS gene. DNA from a patient with a translocation breakpoint in the gene permitted orientation of the contig in relation to the centromere.
In a 12-year-old boy with MPS II, Sukegawa et al. (1992) identified a missense mutation in the IDS gene (300823.0001).
In 6 patients with Hunter syndrome, Flomen et al. (1992) identified mutations in the IDS gene, including a complete deletion, a nonsense mutation, a point mutation that created a novel splice site, and 3 missense mutations (see, e.g., 300823.0002-300823.0006).
Sukegawa et al. (1995) described 8 new examples of point mutations in the IDS gene in Japanese Hunter syndrome patients exhibiting various degrees of severity.
Rathmann et al. (1996) identified IDS mutations in 31 families/patients with MPS II. Twenty mutations were novel and unique and another was novel but was found in 3 unrelated patients. One of the mutations detected was of special interest as it is an A-to-G substitution in an intron far from the coding region that is deleterious because it creates a new 5-prime splice donor site that results in the inclusion of a 78-bp intronic sequence (300823.0014). The authors analyzed a total of 101 point mutations in the coding region and found that they tended to be more frequent in exons 3, 8, and 9. CpG dinucleotides were involved in 47% of the point mutations, of which G:C-to-A:T transitions constituted nearly 80%. Almost all recurrent point mutations involved CpG sites. Analysis of a collection of 50 families studied by this group revealed that mutations occurred more frequently in male meioses; they estimated the male-to-female ratio to be between 3.76 and 6.3.
The methylation pattern of CpG sites of a housekeeping gene correlates with the likelihood of mutation. More than 35% of the separate point mutations in the IDS gene causing MPS II are found in CpG sites as transitional events. To gain insight into the relationship between methylation status and CpG hotspot mutations, Tomatsu et al. (2004) investigated patterns of cytosine methylation in the entire IDS gene, except for introns 4-8. Bisulfite genomic sequencing was performed on the normal leukocyte DNA. The data showed that (1) cytosine methylation at the CpG sites was extensive, except for those present from the promoter region to a portion of intron 3; (2) a sharp boundary of methylated-nonmethylated regions was observed at the 5-prime flanking region, whereas a gradual change in methylation was observed in the 2.0-kb segment in the 3-prime flanking region; (3) the boundary of the 5-prime flanking region contained multiple SP1 (189906) sites and the TATA box; (4) the CpG sites in exons 1 and 2 were hypomethylated and were associated only with rare transitional mutations, and although the CpG sites in exon 3 were also hypomethylated, they were associated with a high rate of transitional mutations; (5) there was no striking sex difference in the methylation patterns in active alleles; and (6) the methylation in both strands was symmetrical, except at the boundary of methylated-unmethylated regions.
Isogai et al. (1998) characterized 25 different small mutations in the IDS gene in a series of 43 Japanese patients with Hunter disease. As in other series, 3 different mutations in codon 468 of exon 9 were found: arg468-to-trp (300823.0012), arg468-to-gln (300823.0013), and arg468-to-leu (300823.0015). All 3 mutations were associated with a severe phenotype.
Ricci et al. (2003) stated that more than 200 different mutations in the IDS gene had been reported in patients with Hunter syndrome.
Kosuga et al. (2016) performed molecular diagnosis in 65 Japanese families with MPS II. They identified 16 novel mutations. Of the 24 males with attenuated Hunter syndrome, 21 had missense mutations, 2 had nonsense mutations (R8X and R443X), and 1 had a 20-amino acid deletion in exon 8 (300823.0006).
In a 12-year-old Japanese boy with Hunter syndrome (MPS2; 309900) of intermediate severity, Sukegawa et al. (1992) found a C-to-T transition at nucleotide 1327 in the IDS gene which resulted in substitution of a termination codon for the normal arginine at position 443 of the peptide sequence. Although the truncated enzyme protein was synthesized, it was unstable. Bunge et al. (1992) found the same mutation in a 3-year-old male (their H20). The patient had skeletal deformities but normal psychomotor development. Froissart et al. (1993) found the same mutation in 2 patients.
In their patient 4 with Hunter syndrome (309900), Flomen et al. (1992) identified a C-to-T transition at nucleotide 1122 in the IDS gene, resulting in substitution of leucine for serine-333, which is a conserved residue within a region of homology among sulfatases. This mutation creates a novel splice site that is preferentially used and results in partial loss of 1 exon in the RNA.
In their patient 5 with Hunter syndrome (309900), Flomen et al. (1992) identified a G-to-C transversion at nucleotide 1629 in the IDS gene, which resulted in the substitution of serine for tryptophan-502 and the introduction of a small polar side chain in a hydrophobic domain.
In their patient 6 with Hunter syndrome (309900), Flomen et al. (1992) identified a C-to-G transversion at nucleotide 603 in the IDS gene, which resulted in the substitution of arginine for proline-160.
In their patient 2 with Hunter syndrome (309900), Flomen et al. (1992) identified a C-to-T transition at nucleotide 638 of the IDS gene, converting arginine 172 to a stop codon.
In their patient 3 with Hunter syndrome (309900), Flomen et al. (1992) found in genomic DNA a C-to-T transition at nucleotide 1246 of the IDS gene, which produced no change in the sense of the codon, i.e., was silent, but created a cryptic donor splice site leading to partial loss of an exon. Sixty basepairs were lost from the cDNA, from G1244 to G1305.
In an 8.5-year-old boy with such severe Hunter syndrome (309900) that bladder and bowel control was never achieved, chronic diarrhea was a major problem, and speech was limited and delayed in development, Beck et al. (1992) demonstrated complete lack of the IDS coding sequences and the simultaneous deletion of both DXS466 and DXS304, 2 markers mapped probably not more than 900 kb from the IDS locus. By following the segregation of an RFLP at the IDS locus, Beck et al. (1992) found that the deletion probably occurred in the germ cells of the patient's maternal grandfather. The 2 patients with IDS deletion reported by Wraith et al. (1991) likewise had severe expression of the disease with epileptic seizures and profound mental retardation; they never attained speech. Ptosis was present in 1 of the 2 patients of Wraith et al. (1991) but was not present in the second patient or in the patient reported by Beck et al. (1992) with deletion of IDS. In an addendum, Beck et al. (1992) cited their results suggesting that DXS466 lies within an intron in the 5-prime half of the IDS gene.
In an 8-year-old patient with very mild manifestations of Hunter syndrome (309900) and normal intelligence, Bunge et al. (1992) identified a TGC-to-GGC transversion in codon 422 of the IDS gene, resulting in the substitution of glycine for cysteine.
In a 5-year-old patient with typical features of Hunter syndrome (309900) and decline in ability to speak, Bunge et al. (1992) identified an AAA-to-AGA transition in codon 135, resulting in substitution of arginine for lysine. In addition, a silent ACC-to-ACT change was found at codon 146.
In a 20-year-old patient with typical features of MPS II (309900) and 'still able to talk,' Bunge et al. (1992) identified a TGG-to-TGA transversion in codon 475 of the IDS gene, converting the trp codon to a stop codon.
In an 8-year-old patient with typical features of Hunter syndrome (309900) and attendance at a special school, Bunge et al. (1992) identified a deletion of 2 bp (CA) from codon 170 (ACA) of the IDS gene. The deletion resulted in a frameshift with 27 altered amino acids and a premature chain termination.
By direct sequencing of RT-PCR products, Crotty et al. (1992) identified a C-to-T transition at nucleotide 1402 of the IDS gene, leading to a replacement of arginine-468 by tryptophan (R468W), in a proband with mild Hunter syndrome (309900). The mutation abolished an MspI restriction site, thus allowing confirmation of the mutant sequence and analysis in family members. The mother was shown to be heterozygous; her serum IDS enzyme activity had previously been shown to be in the heterozygote range. The diagnosis was first suggested at the age of 2.3 years and confirmed by measurement of elevated urinary glycosaminoglycan excretion and absence of serum IDS enzyme activity. At age 2.9 years, the child's IQ was 115; the patient was 5 years old at the time of the report.
Although the arg468-to-trp mutation (300823.0012) was associated with a mild form of MPS II, Whitley et al. (1993) found very severe MPS II (309900) manifestations in a boy who was found to have a mutation in the same codon: a G-to-A transition at nucleotide 1403 of the IDS gene resulted in substitution of glutamine for arginine-468 (R468Q). In a note added in proof, it was reported that fibroblast cultures showed a large acrocentric supernumerary marker chromosome, which presumably was responsible for the quantitatively and qualitatively atypical features of the proband's face. The proband died at the age of 23 months.
Sukegawa et al. (1997) described the findings in a girl with severe Hunter syndrome. She had a normal karyotype but a marked deficiency of iduronate 2-sulfatase activity in lymphocytes and cultured fibroblasts. The common R468Q mutation was identified in the IDS gene. RT-PCR showed her cDNA to represent only the R468Q allele, although at the genomic level she was heterozygous, with one normal allele. The brother had the R468Q mutation, and her mother was a carrier of this mutation. In genomic DNA from the patient's fibroblasts, only the paternal allele of the androgen receptor gene, a gene subjected to differential methylation of the inactive X chromosome, was methylated. These findings were interpreted as indicating that the severe form of Hunter disease in this girl was the result of selective expression of the maternal allele carrying the missense mutation R468Q, which in turn resulted from skewed X inactivation of the paternal nonmutant X chromosome.
Rathmann et al. (1996) detected a splice site mutation in the IDS gene in a 6-year-old boy presenting with a mild course of mucopolysaccharidosis type II (309900). Screening for mutations by amplification of single exons and SSCP did not reveal any aberration; however, analysis of the 3-prime half of the IDS mRNA by agarose gel electrophoresis detected bands of 3 different sizes. The most abundant transcript was approximately 80 to 100 bp larger than the mRNA of an unaffected control. Furthermore, there was an apparently normal-sized fragment and a third abnormally small fragment of approximately 90 to 110 bp. Direct sequencing of the corresponding PCR-amplified cDNA fragments revealed that the largest message contained a 78-bp insertion between exons 7 and 8. The same 78-bp sequence was found in the smaller transcript, although in that case it was flanked by exons 7 and 9 of the IDS gene (i.e., exon 8 was skipped during splicing). The DNA fragment running a roughly equivalent distance as the normal-sized message in the agarose gel electrophoresis was considered most likely a heteroduplex formed by the 2 mRNA/cDNA species just mentioned, because only the larger and smaller fragments were detected. The presumed 3-prime acceptor splice consensus sequence (aggt) at the beginning of the 78-bp sequence was found to be unaltered, whereas an A-to-G transition was identified at the fifth nucleotide following the last base of the included sequence. This substitution created a new 5-prime splice donor site (aagtgaa-to-AAgtgag) and resulted in the inclusion of a 78-bp intronic sequence. Rathmann et al. (1996) suggested that neither translation product derived from the 2 alternative splice transcripts had IDS activity because each encoded a largely truncated IDS protein due to an early termination signal in the 78-bp inclusion.
Mutations at codon 468 (R468) of the IDS gene have been noted in MPS II patients of various ethnic origins (Crotty et al., 1992; Hopwood et al., 1993; Whitley et al., 1993). In a patient with a severe MPS II (309900) phenotype, Isogai et al. (1998) identified a G-to-T transversion at nucleotide 1403 of the IDS gene, resulting in an arg468-to-leu (R468L) substitution. In their series of Japanese patients, 5 (29%) of 17 patients with missense mutations had a change in codon R468. They demonstrated that the CpG dinucleotide at this site was methylated, suggesting that this R468 codon is a mutation hotspot.
In a Japanese patient with a severe form of mucopolysaccharidosis type II (309900), Sukegawa et al. (1995) described an in-frame deletion of 3 nucleotides, 473delTCC, in exon 3 of the IDS gene, resulting in the loss of serine-117. Bonuccelli et al. (2001) studied the effects of this mutation by transient expression of the mutation in COS-7 cells. No significant IDS activity was identified.
Ricci et al. (2003) described an Italian patient with Hunter syndrome (309900) who had 2 missense changes involving adjacent amino acids, met488-to-ile (M488I) and gly489-to-ala (G489A). In vitro expression by COS-7 cells confirmed the G489A mutation as causative. The M488I mutation was associated with residual activity. Although a cumulative effect of the 2 mutations could be excluded 'in vitro,' Ricci et al. (2003) were cautious about drawing a conclusion with regard to the possible role that the 2 mutations could have played 'in vivo' in modulating the phenotype of the patient. At the age of 23 years, the patient showed clinical manifestations of intermediate severity.
Beck, M., Steglich, C., Zabel, B., Dahl, N., Schwinger, E., Hopwood, J. J., Gal, A. Deletion of the Hunter gene and both DXS466 and DXS304 in a patient with mucopolysaccharidosis type II. Am. J. Med. Genet. 44: 100-103, 1992. [PubMed: 1355630] [Full Text: https://doi.org/10.1002/ajmg.1320440123]
Bielicki, J., Freeman, C., Clements, P. R., Hopwood, J. J. Human liver iduronate-2-sulphatase: purification, characterization and catalytic properties. Biochem. J. 271: 75-86, 1990. [PubMed: 2222422] [Full Text: https://doi.org/10.1042/bj2710075]
Bondeson, M.-L., Dahl, N., Malmgren, H., Kleijer, W. J., Tonnesen, T., Carlberg, B.-M., Pettersson, U. Inversion of the IDS gene resulting from recombination with IDS-related sequences is a common cause of the Hunter syndrome. Hum. Molec. Genet. 4: 615-621, 1995. [PubMed: 7633410] [Full Text: https://doi.org/10.1093/hmg/4.4.615]
Bondeson, M.-L., Malmgren, H., Dahl, N., Carlberg, B.-M., Pettersson, U. Presence of an IDS-related locus (IDS2) in Xq28 complicates the mutational analysis of Hunter syndrome. Europ. J. Hum. Genet. 3: 219-227, 1995. [PubMed: 8528670] [Full Text: https://doi.org/10.1159/000472302]
Bonuccelli, G., Di Natale, P., Corsolini, F., Villani, G., Regis, S., Filocamo, M. The effect of four mutations on the expression of iduronate-2-sulfatase in mucopolysaccharidosis type II. Biochim. Biophys. Acta 1537: 233-238, 2001. [PubMed: 11731225] [Full Text: https://doi.org/10.1016/s0925-4439(01)00075-8]
Bunge, S., Steglich, C., Beck, M., Rosenkranz, W., Schwinger, E., Hopwood, J. J., Gal, A. Mutation analysis of the iduronate-2-sulfatase gene in patients with mucopolysaccharidosis type II (Hunter syndrome). Hum. Molec. Genet. 1: 335-339, 1992. [PubMed: 1303211] [Full Text: https://doi.org/10.1093/hmg/1.5.335]
Bunge, S., Steglich, C., Zuther, C., Beck, M., Morris, C. P., Schwinger, E., Schinzel, A., Hopwood, J. J., Gal, A. Iduronate-2-sulfatase gene mutations in 16 patients with mucopolysaccharidosis type II (Hunter syndrome). Hum. Molec. Genet. 2: 1871-1875, 1993. [PubMed: 8281149] [Full Text: https://doi.org/10.1093/hmg/2.11.1871]
Cantz, M., Chrambach, A., Neufeld, E. F. Characterization of the factor deficient in the Hunter syndrome by polyacrylamide gel electrophoresis. Biochem. Biophys. Res. Commun. 39: 936-942, 1970. [PubMed: 4987382] [Full Text: https://doi.org/10.1016/0006-291x(70)90414-6]
Crotty, P. L., Braun, S. E., Anderson, R. A., Whitley, C. B. Mutation R468W of the iduronate-2-sulfatase gene in mild Hunter syndrome (mucopolysaccharidosis type II) confirmed by in vitro mutagenesis and expression. Hum. Molec. Genet. 1: 755-757, 1992. [PubMed: 1284597] [Full Text: https://doi.org/10.1093/hmg/1.9.755]
Daniele, A., Faust, C. J., Herman, G. E., Di Natale, P., Ballabio, A. Cloning and characterization of the cDNA for the murine iduronate sulfatase gene. Genomics 16: 755-757, 1993. [PubMed: 8325651] [Full Text: https://doi.org/10.1006/geno.1993.1259]
DiNatale, P., Ronsisvalle, L. Identification and partial characterization of two enzyme forms of iduronate sulfatase from human placenta. Biochim. Biophys. Acta 661: 106-111, 1981. [PubMed: 6945876] [Full Text: https://doi.org/10.1016/0005-2744(81)90088-7]
Faust, C. J., Verkerk, A. J. M. H., Wilson, P. J., Morris, C. P., Hopwood, J. J., Oostra, B. A., Herman, G. E. Genetic mapping on the mouse X chromosome of human cDNA clones for the fragile X and Hunter syndromes. Genomics 12: 814-817, 1992. [PubMed: 1572654] [Full Text: https://doi.org/10.1016/0888-7543(92)90314-i]
Flomen, R. H., Green, E. P., Green, P. M., Bentley, D. R., Giannelli, F. Determination of the organisation of coding sequences within the iduronate sulphate sulphatase (IDS) gene. Hum. Molec. Genet. 2: 5-10, 1993. [PubMed: 8490623] [Full Text: https://doi.org/10.1093/hmg/2.1.5]
Flomen, R. H., Green, P. M., Bentley, D. R., Giannelli, F., Green, E. P. Detection of point mutations and a gross deletion in six Hunter syndrome patients. Genomics 13: 543-550, 1992. [PubMed: 1639384] [Full Text: https://doi.org/10.1016/0888-7543(92)90123-a]
Froissart, R., Blond, J.-L., Maire, I., Guibaud, P., Hopwood, J. J., Mathieu, M., Bozon, D. Hunter syndrome: gene deletions and rearrangements. Hum. Mutat. 2: 138-140, 1993. [PubMed: 8318991] [Full Text: https://doi.org/10.1002/humu.1380020214]
Hopwood, J. J., Bunge, S., Morris, C. P., Wilson, P. J., Steglich, C., Beck, M., Schwinger, E., Gal, A. Molecular basis of mucopolysaccharidosis type II: mutations in the iduronate-2-sulphatase gene. Hum. Mutat. 2: 435-442, 1993. [PubMed: 8111411] [Full Text: https://doi.org/10.1002/humu.1380020603]
Isogai, K., Sukegawa, K., Tomatsu, S., Fukao, T., Song, X.-Q., Yamada, Y., Fukuda, S., Orii, T., Kondo, N. Mutation analysis in the iduronate-2-sulphatase gene in 43 Japanese patients with mucopolysaccharidosis type II (Hunter disease). J. Inherit. Metab. Dis. 21: 60-70, 1998. [PubMed: 9501270] [Full Text: https://doi.org/10.1023/a:1005363414792]
Kosuga, M., Mashima, R., Hirakiyama, A., Fuji, N., Kumagai, T., Seo, J.-H., Nikaido, M., Saito, S., Ohno, K., Sakuraba, H., Okuyama, T. Molecular diagnosis of 65 families with mucopolysaccharidosis type II (Hunter syndrome) characterized by 16 novel mutations in the IDS gene: genetic, pathological, and structural studies on iduronate-2-sulfatase. Molec. Genet. Metab. 118: 190-197, 2016. [PubMed: 27246110] [Full Text: https://doi.org/10.1016/j.ymgme.2016.05.003]
Malmgren, H., Carlberg, B.-M., Pettersson, U., Bondeson, M.-L. Identification of an alternative transcript from the human iduronate-2-sulfatase (IDS) gene. Genomics 29: 291-293, 1995. [PubMed: 8530090] [Full Text: https://doi.org/10.1006/geno.1995.1249]
Palmieri, G., Capra, V., Romano, G., D'Urso, M., Johnson, S., Schlessinger, D., Morris, P., Hopwood, J., Di Natale, P., Gatti, R., Ballabio, A. The iduronate sulfatase gene: isolation of a 1.2-Mb YAC contig spanning the entire gene and identification of heterogeneous deletions in patients with Hunter syndrome. Genomics 12: 52-57, 1992. [PubMed: 1733863] [Full Text: https://doi.org/10.1016/0888-7543(92)90405-h]
Rathmann, M., Bunge, S., Beck, M., Kresse, H., Tylki-Szymanska, A., Gal, A. Mucopolysaccharidosis type II (Hunter syndrome): mutation 'hot spots' in the iduronate-2-sulfatase gene. Am. J. Hum. Genet. 59: 1202-1209, 1996. [PubMed: 8940265]
Ricci, V., Filocamo, M., Regis, S., Corsolini, F., Stroppiano, M., Di Duca, M., Gatti, R. Expression studies of two novel in cis-mutations identified in an intermediate case of Hunter syndrome. Am. J. Med. Genet. 120A: 84-87, 2003. [PubMed: 12794697] [Full Text: https://doi.org/10.1002/ajmg.a.10215]
Sukegawa, K., Song, X.-Q., Masuno, M., Fukao, T., Shimozawa, N., Fukuda, S., Isogai, K., Nishio, H., Matsuo, M., Tomatsu, S., Kondo, N., Orii, T. Hunter disease in a girl caused by R468Q mutation in the iduronate-2-sulfatase gene and skewed inactivation of the X chromosome carrying the normal allele. Hum. Mutat. 10: 361-367, 1997. [PubMed: 9375851] [Full Text: https://doi.org/10.1002/(SICI)1098-1004(1997)10:5<361::AID-HUMU5>3.0.CO;2-I]
Sukegawa, K., Tomatsu, S., Fukao, T., Iwata, H., Song, X.-Q., Yamada, Y., Fukuda, S., Isogai, K., Orii, T. Mucopolysaccharidosis type II (Hunter disease): identification and characterization of eight point mutations in the iduronate-2-sulfatase gene in Japanese patients. Hum. Mutat. 6: 136-143, 1995. [PubMed: 7581397] [Full Text: https://doi.org/10.1002/humu.1380060206]
Sukegawa, K., Tomatsu, S., Tamai, K., Ikeda, M., Sasaki, T., Masue, M., Fukuda, S., Yamada, Y., Orii, T. Intermediate form of mucopolysaccharidosis type II (Hunter disease): a C-1327 to T substitution in the iduronate sulfatase gene. Biochem. Biophys. Res. Commun. 183: 809-813, 1992. [PubMed: 1550586] [Full Text: https://doi.org/10.1016/0006-291x(92)90555-y]
Tomatsu, S., Orii, K. O., Bi, Y., Gutierrez, M. A., Nishioka, T., Yamaguchi, S., Kondo, N., Orii, T., Noguchi, A., Sly, W. S. General implications for CpG hot spot mutations: methylation patterns of the human iduronate-2-sulfatase gene locus. Hum. Mutat. 23: 590-598, 2004. [PubMed: 15146464] [Full Text: https://doi.org/10.1002/humu.20046]
Whitley, C. B., Anderson, R. A., Aronovich, E. L., Crotty, P. L., Anyane-Yeboa, K., Russo, D., Warburton, D. Caveat to genotype-phenotype correlation in mucopolysaccharidosis type II: discordant clinical severity of R468W and R468Q mutations of the iduronate-2-sulfatase gene. Hum. Mutat. 2: 235-237, 1993. [PubMed: 8364592] [Full Text: https://doi.org/10.1002/humu.1380020313]
Wilson, P. J., Meaney, C. A., Hopwood, J. J., Morris, C. P. Sequence of the human iduronate 2-sulfatase (IDS) gene. Genomics 17: 773-775, 1993. [PubMed: 8244397] [Full Text: https://doi.org/10.1006/geno.1993.1406]
Wilson, P. J., Morris, C. P., Anson, D. S., Occhiodoro, T., Bielicki, J., Clements, P. R., Hopwood, J. J. Hunter syndrome: isolation of an iduronate-2-sulfatase cDNA clone and analysis of patient DNA. Proc. Nat. Acad. Sci. 87: 8531-8535, 1990. [PubMed: 2122463] [Full Text: https://doi.org/10.1073/pnas.87.21.8531]
Wilson, P. J., Suthers, G. K., Callen, D. F., Baker, E., Nelson, P. V., Cooper, A., Wraith, J. E., Sutherland, G. R., Morris, C. P., Hopwood, J. J. Frequent deletions at Xq28 indicate genetic heterogeneity in Hunter syndrome. Hum. Genet. 86: 505-508, 1991. [PubMed: 1901826] [Full Text: https://doi.org/10.1007/BF00194643]
Wraith, J. E., Cooper, A., Thornley, M., Wilson, P. J., Nelson, P. V., Morris, C. P., Hopwood, J. J. The clinical phenotype of two patients with a complete deletion of the iduronate-2-sulphatase gene (mucopolysaccharidosis II--Hunter syndrome). Hum. Genet. 87: 205-206, 1991. [PubMed: 1906048] [Full Text: https://doi.org/10.1007/BF00204183]