SELECTIVE SCREENING OF 10,000 HIGH-RISK BRAZILIAN PATIENTS FOR THE DETECTION OF INBORN-ERRORS OF METABOLISM

The number of diagnosed inborn errors of metabolism (IEM) is growing c onstantly due to the improvement and widespread availability of analyt ical techniques. In 1982, a laboratory for the detection of IEM was se t up in Porto Alegre, Brazil, and became a national reference centre f or the diagnosis of these disorders. Ten thousand patients with signs and symptoms suggestive of IEM were investigated in our laboratory fro m 1982 to 1995 using specific protocols which included tests for the d etection of glucosaminoglycans (GAGS), amino acids, sugars, oligosacch arides, sialyloligosaccharides, organic acids, as well as various meta bolites. The biochemical investigation was completed in 9,901 patients and an IEM was detected in 647 cases (6.5%). Groups of IEM of higher incidence in our sample were lysosomal storage disorders (59.8%) and a minoacidopathies (21.2%). The disorders most frequently diagnosed were classical phenylketonuria, GM1 gangliosidosis, mucopolysaccharidosis type I, mucopolysaccharidosis type VI and metachromatic leukodystrophy . Conclusion This study shows that the establishment of reference cent res for the investigation of rare genetic diseases is a suitable appro ach to the study of IEM in developing countries such as Brazil.