Molecular analysis of iduronate -2- sulfatase gene in Tunisian patients with mucopolysaccharidosis type II

Abstract

Mucopolysaccharidosis type II (MPS II, Hunter syndrome) is X-linked recessive lysosomal storage disorder resulting from the defective activity of the enzyme iduronate-2-sulfatase (IDS). Hunter disease can vary from mild to severe, depending on the level of enzyme deficiency. We report the IDS mutation and polymorphisms causing the Hunter syndrome in patients from one family in TunisiaPatients and methodsA preliminary diagnosis was made by qualitative detection of urinary glycosaminoglycans of the suspected MPS II probands. The IDS mutation and polymorphisms were determined on these probands and their family members by amplifying and sequencing each of the exons and intron-exon junctions of IDS gene.ResultsThe studied probands were homoallelic for p.R88P mutation. In addition, three known polymorphisms/sequence variants: IVS3-16 (c.419-16 delT), T214M (c.641C > T), T146T (c.438 C > T), IVS5-87(c.709-87G > A) and one previously unknown: IVS7+38(c.1006+38T > C were identified in the MPS II patients. These are the first Tunisian MPS II patients to be genotyped.ConclusionThe identification of these mutation and polymorphisms and their genotype-phenotype correlation should facilitate prenatal diagnosis and counseling for MPS II in Tunisia, where a very high rate of consanguinity exists.

The mutational spectrum of hunter syndrome reveals correlation between biochemical and clinical profiles in Tunisian patients

“…Primer sequences and annealing temperature are provided in Table 1.Nevertheless, to avoid the amplification of the IDS pseudogene, we have used the primers according which have been previously described [9]. The PCR reactions were performed according to Chkioua et al [10]. To identify the type and position of the genetic variants, PCR products were purified from excess primers and dNTP with FavorPrep kitTM (Favorgen(R) Biotech Corp) and were sequenced in both forward and reverse directions using the same PCR primers with the Big DyeTerminator v1.1 Cycle Sequencing Kit (Applied Biosystems).…”

The mutational spectrum of Hunter syndrome reveals correlation between biochemical and clinical profiles in Tunisian patients

“…However, in patients with family history, only the exons were analysed. Primer sequences and annealing temperature are provided in Table 3.Nevertheless, to avoid the amplification of the IDS pseudogene, we have used the primers according which have been previously described [9].The PCR reactions were performed according to Chkioua et al [10]. To identify the type and position of the genetic variants, PCR products were purified from excess primers and dNTP with FavorPrep kitTM (Favorgen(R) Biotech Corp) and were sequenced in both forward and reverse directions using the same PCR primers with the Big DyeTerminator v1.1 Cycle Sequencing Kit (Applied Biosystems).The PCR products were purified by Illustra MicroSpin G-50 Columns (GE Healthcare) and electrophoresed on an automated ABI PRISM 310 genetic analyser and interpreted with ChromasPro 2.4.1 software.…”

The mutational spectrum of Hunter syndrome reveals correlation between biochemical and clinical profiles in Tunisian patients

“…Nevertheless, to avoid the amplification of the IDS pseudogene, we have used the primers according which have been previously described [9]. The PCR reactions were performed according to Chkioua et al [10]. To identify the type and position of the genetic variants, PCR products were purified from excess primers and dNTP with FavorPrep kitTM (Favorgen(R) Biotech Corp) and were sequenced in both forward and reverse directions using the same PCR primers with the Big DyeTerminator v1.1 Cycle Sequencing Kit (Applied Biosystems).…”