engleski

Frequency of mutations associated with arylsulfatase A pseudodeficiency in multiple sclerosis

Arylsulfatase A (ASA) is a lysosomal enzyme involved in catabolism of sulfatides, major lipid constituents of oligodendrocyte membranes. Mutations in the ASA gene leading to ASA pseudodeficiency (ASA-PD) could contribute to pathogenesis of multiple sclerosis due to death of oligodendrocyte subpopulations caused by sulfatide accumulation and exposure of myelin antigens. The aim of this study was to estimate the frequency of two most common ASA-PD mutations, designated as N350S and 1524+95 A-G mutations, in patients with multiple sclerosis (MS) in comparison with healthy individuals. Patients with diagnosis of multiple sclerosis (N=45) and individuals in control group participated in this study (N=125 ; individuals in control group were included in a previous study of two described ASA-PD mutations frequency in Croatia). Genomic DNA was extracted from leukocytes, and two fragments of ASA gene were amplified using specific primers and treated with adequate restriction enzymes. In addition, the ASA activity was measured in leukocyte homogenates derived from 45 MS patients and 29 controls, by spectrophotometric method using p-nitrocatechol sulfate as a chromogenic substrate. Genotyping for ASA-PD mutations showed higher frequencies of both analyzed mutated alleles in MS patients in comparison with healthy individuals. The frequency of N350S mutation was estimated at 10.7 % in MS patients vs. 6.4 % in controls, while frequency for the 1524+95 A-G mutation was found to be 2.6-fold higher in MS patients (7.3 % in MS vs. 2.8 % in controls). The MS patients were heterozygous for analyzed mutations. Majority of patients were heterozygous carriers of both mutations while 3 patients carried independent N350S mutation. Determination of ASA activity showed slightly lower values in MS patients in comparison with controls. Measured ASA activities were in the normal range in majority of MS patients (60 – 300 nmol h-1 mg-1) ; however a distribution of obtained results clearly showed a trend toward lower values of enzyme activity in MS patients. Higher frequencies of two ASA-PD mutations in MS patients, as estimated in this study, indicate that these mutations and probably other mutations in the ASA gene could contribute to pathogenesis and clinical features of multiple sclerosis.

arylsulfatase A; pseudodeficiency mutations; multiple sclerosis

Časopis je indeksiran u Neuroscience Citation indeksu i EMBASE/Excerpta Medica.