Arylsulfatase A pseudodeficiency in healthy Brazilian individuals

Molecular alterations associated with arylsulfatase A pseudodeficiency (ASA -PD) were characterized by PCR and restriction endonuclease analysis in a s ample of healthy individuals from Brazil. ASA activity was also assayed in all subjects. Two individuals homozygous for the N350S and 1524+95A-->G mut ations were detected, corresponding to a frequency of 1.17% (1 of 324 allel es), The individual frequency of the N350S mutation was 20.7% (71 of 342 al leles) and 7.9% (27 of 342 alleles) for the 1524+95A-->G mutation. The freq uency of the ASA-PD allele in our population was estimated to be 7.9%. This is the first report of ASA-PD allele frequency in a South American populat ion. In addition, the methods used are effective and suitable for applicati on in countries with limited resources. Ail patients with low ASA activity should be screened for ASA-PD as part of the diagnostic procotol for metach romatic leukodystrophy.