[Mucopolysaccharidosis: 20-year enzymatic diagnosis in Cuba]. / Mucopolisacaridosis: diagnostico enzimatico de 20 anos en Cuba.

INTRODUCTION: Mucopolysaccharidoses (MPS), which belong to the family of inborn errors of metabolism, are characterised by their severe clinical manifestations (skeletal, neurological and visceral) and a chronic, progressive course leading to death at early stages of life. AIM. To accomplish an enzymatic diagnosis and characterise MPS within the Cuban population. SUBJECTS AND METHODS: A total of 664 patients with a clinical suspicion of some type of MPS were referred to the Institute of Neurology and Neurosurgery in Havana in order to determine a possible enzymatic deficiency and to classify the type of MPS involved in each case. Enzymatic determinations of alpha-L-iduronidasa, alpha-N-acetylglucosaminidase, beta-galactosidase, arylsulphatase B and beta-glucuronidase were performed in leukocyte homogenate for MPS I, IIIB, IVB, VI and VII, respectively, in patients, parents and controls. RESULTS. In all, 42 cases of MPS were diagnosed: MPS I (62%, n = 26), MPS VI (29%, n = 12), MPS IIIB (7%, n = 3) and MPS IVB (2%, n = 1). No patients with MPS VII were identified. The patients diagnosed with MPS were of both sexes and ages ranged between 4 months and 10 years. The specific activity of the enzymes that were studied was deficient in patients with respect to parents and controls. The percentage of activity was lower in patients compared to parents. CONCLUSIONS: These studies made it possible to evaluate the enzymatic deficiencies and to establish the diagnosis of MPS I, MPS IIIB, MPS IVB, MPS VI and MPS VII in the Cuban population.