Unique frequency of known mutations in Brazilian MPS I patients

a, L218P, A327P, R383H, W402X, andP533R—was estimated in a group of 24 in-dex cases with mucopolysaccharidosis typeI. Three affected relatives were also ana-lysed. Six of the 10 mutations screened werepresent in our patients (Q70X, R89Q, A327P,R383H, W402X, and P533R). These muta-tions account for 54% of the alleles; 37% ofthe genotypes were defined. Frequencies ofthese mutations are markedly differentfrom those in the literature. A novel combi-nation Q70X/A327P is described. This wasthe first time Brazilian MPS I patients wereanalysed with molecular techniques. Thelow frequency of common mutations indi-cates that a more comprehensive analysis ofthe