Mucopolysaccharidoses types I and IIIA: Diagnosis and identification of novel polymorphisms associated with common
Houda El Fissi1, Fadoua Bouzid1,2, Mohammed Said Sebbar3
1Laboratory of Biotechnologies and Valorization of Natural Resources, Department of Biology- Faculty of Sciences, Ibn Zohr University, Agadir, Morocco.
Background:
Mucopolysaccharidoses types I and IIIA are lysosomal storage diseases caused by mutations in the IDUA and SGSH genes, leading to deficiencies in α-L-iduronidase and heparan sulfamidase, respectively. These progressive, autosomal recessive disorders require early diagnosis.
Purpose:
The study targeted and investigated the p.Pro533Arg mutation, known to cause mucopolysaccharidosis type I, and the p.Arg377Cys mutation, associated with mucopolysaccharidosis IIIA, in newly recruited Moroccan families. In parallel, variants/polymorphisms associated with these mutations were searched for.
Methods:
Researchers employed RFLP assays for the p.Pro533Arg and p.Arg377Cys mutations and genomic PCR sequencing for variant detection. PolyPhen-2, MutPred2, SIFT, and MutationTaster were used to assess the pathogenicity of these variants, helping to evaluate their potential impact on disease.
Results:
The p.Pro533Arg mutation was found in newly recruited families with Hurler syndrome, consistent with previous findings. Similarly, the p.Arg377Cys mutation was present in a newly recruited family with Sanfilippo A syndrome. DNA sequencing revealed five SNPs four in the IDUA gene and one in the SGSH gene with three IDUA SNPs and one SGSH SNP being novel.
Conclusion:
The p.Pro533Arg and p.Arg377Cys mutations are common among Moroccan patients with MPS I and MPS IIIA, respectively. The ability to detect these mutations using restriction endonucleases allows for molecular diagnosis in affected families. Five polymorphisms were identified among them four are novel.
