Skip to Main content Skip to Navigation
Journal articles

Determination of arylsulfatase A pseudodeficiency allele and haplotype frequency in the Tunisian population

Abstract : Arylsulfatase A (ASA) is a lysosomal enzyme involved in the catabolism of cerebroside sulfate. ASA deficiency is associated with metachromatic leukodystrophy (MLD). Low ASA activities have also been reported in a more common condition with no apparent clinical consequences termed ASA pseudo-deficiency (ASA-PD) which is associated with two linked mutations in the ASA gene (c.1049A > G and c.*96A > G). This study aimed to investigate the frequency of the two ASA-PD variants and their linkage disequilibrium (LD) among Tunisians. ASA-PD variants were detected in 129 healthy Tunisians and their frequencies were compared to those described worldwide. The frequency of the PD allele was estimated at 17.4 % for the overall sample, with c.1049A > G and c.*96A > G frequencies of 25.6 and 17.4 %, respectively. This study also revealed a high LD between the two ASA-PD variants (r (2) = 0.61). Inter-population analysis revealed similarities in the ASA-PD genetic structure between Tunisians and populations from Middle East with c.*96A > G frequencies being the highest in the world. A significant North vs. South genetic differentiation in the ASA-PD frequency was also observed in Tunisian population who seems genetically intermediate between Africans, Middle-Easterners and Europeans. This is the first report on the allele frequency of the ASA-PD in North Africa, revealing a relatively high frequency of the PD allele among Tunisians. This study gives also evidence on the importance of discriminating ASA-PD allele from pathological mutations causing MLD and supporting enzymatic activity testing with both sulfatiduria determination and genetic testing in the differential diagnosis of MLD in the Tunisian population.
Document type :
Journal articles
Complete list of metadatas
Contributor : Institut Pasteur Tunis <>
Submitted on : Tuesday, December 6, 2016 - 2:07:45 PM
Last modification on : Wednesday, October 28, 2020 - 9:52:04 AM



Nizar Ben Halim, Imen Dorboz, Rym Kefi, Najla Kharrat, Eléonore Eymard-Pierre, et al.. Determination of arylsulfatase A pseudodeficiency allele and haplotype frequency in the Tunisian population. Neurological Sciences, Springer Verlag, 2016, 37 (3), pp.403-409. ⟨10.1007/s10072-015-2417-5⟩. ⟨pasteur-01374976⟩



Record views