ABSTRACT
Molecular alterations associated with arylsulfatase A pseudodeficiency (ASA-PD) were characterized by PCR and restriction endonuclease analysis in a sample of healthy individuals from Brazil. ASA activity was also assayed in all subjects. Two individuals homozygous for the N350S and 1524+95A->G mutations were detected, corresponding to a frequency of 1.17 percent (4 of 324 alleles). The individual frequency of the N350S mutation was 20.7 percent (71 of 342 alleles) and 7.9 percent (27 of 342 alleles) for the 1524+95A->G mutation. The frequency of the ASA-PD allele in our population was estimated to be 7.9 percent. This is the first report of ASA-PD allele frequency in a South American population. In addition, the methods used are effective and suitable for application in countries with limited resources. All patients with low ASA activity should be screened for ASA-PD as part of the diagnostic procotol for metachromatic leukodystrophy