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Mucopolysaccharidosis type I: molecular characteristics of two novel alpha-L-iduronidase mutations in Tunisian patients
- Source :
- Diagnostic Pathology, Diagnostic Pathology, Vol 6, Iss 1, p 47 (2011)
- Publication Year :
- 2011
- Publisher :
- Springer Science and Business Media LLC, 2011.
-
Abstract
- Background Mucopolysaccharidosis type I (MPS I) is an autosomal storage disease resulting from defective activity of the enzyme α-L-iduronidase (IDUA). This glycosidase is involved in the degradation of heparan sulfate and dermatan sulfate. MPS I has severe and milder phenotypic subtypes. Aim of study: This study was carried out on six newly collected MPS I patients recruited from many regions of Tunisia. Patients and methods: Mutational analysis of the IDUA gene in unrelated MPS I families was performed by sequencing the exons and intron-exon junctions of IDUA gene. Results Two novel IDUA mutations, p.L530fs (1587_1588 insGC) in exon 11 and p.F177S in exon 5 and two previously reported mutations p.P533R and p.Y581X were detected. The patient in family 1 who has the Hurler phenotype was homozygous for the previously described nonsense mutation p.Y581X. The patient in family 2 who also has the Hurler phenotype was homozygous for the novel missense mutation p.F177S. The three patients in families 3, 5 and 6 were homozygous for the p.P533R mutation. The patient in family 4 was homozygous for the novel small insertion 1587_1588 insGC. In addition, eighteen known and one unknown IDUA polymorphisms were identified. Conclusion The identification of these mutations should facilitate prenatal diagnosis and counseling for MPS I in Tunisia. Background Mucopolysaccharidosis type I (MPS I) is an autosomal recessive lysosomal storage disorder caused by the deficient activity of the enzyme of α-L-iduronidase (IDUA, EC 3.2.1.76). This glycosidase is involved in the degradation of heparan sulfate and dermatan sulfate. The clinical phenotype of MPS I ranges from the very severe in Hurler syndrome (MPS IH) to the relatively benign in Scheie syndrome (MPS IS), with an intermediate phenotype designated Hurler/Scheie (MPS IH/S) 1. Isolation of complementary and genomic DNAs encoding human α -L- iduronidase 23 have enable the identification of mutations underlying the enzyme defect and resulting in MPS I clinical phenotype. More than 100 mutations have been reported in patients with the MPS I subtypes (Human Gene Mutation Database; http://www.hgmd.org). High prevalence of the common mutations p.W402X and p.Q70X has been described; both of them in the severe clinical forms 45. A high prevalence of common mutation p.P533R has also been described in MPS I patients with various phenotypes 56. In addition, rare mutations including single base substitution, deletion, insertion and splicing site mutation have been identified 7, indicating a high degree of allelic heterogeneity in IDUA gene. Here, we described two novel IDUA mutations in MPS I Tunisian patients. These lesions were homoallelic in all the patients of the six families investigated as consanguineous marriages are still frequent in Tunisia 8.
- Subjects :
- Male
congenital, hereditary, and neonatal diseases and abnormalities
Tunisia
Histology
Genotype
Mucopolysaccharidosis I
DNA Mutational Analysis
Mutation, Missense
Biology
Dermatan sulfate
Pathology and Forensic Medicine
Iduronidase
Mucopolysaccharidosis type I
Exon
chemistry.chemical_compound
lcsh:Pathology
Humans
Child
skin and connective tissue diseases
Gene
Family Health
Genetics
Research
nutritional and metabolic diseases
General Medicine
Heparan sulfate
Molecular biology
chemistry
Child, Preschool
Female
lcsh:RB1-214
Subjects
Details
- ISSN :
- 17461596
- Volume :
- 6
- Database :
- OpenAIRE
- Journal :
- Diagnostic Pathology
- Accession number :
- edsair.doi.dedup.....e548a7171a6c9d212fa49c53eb92df1b