ABSTRACT
As Mucopolissacaridoses (MPS) correspondem a um grupo de doenças genéticas raras caracterizadas peladeficiência/ausência de enzimas lisossomais responsáveis pela degradação de glicosaminoglicanos (GAG). Uma vez não degradados,os GAG se acumulam em diversos tecidos do organismo, causando uma série de complicações patológicas, que iniciam desde o período fetal até a fase infantil. Foi realizada a implantação de um protocolo laboratorial para o diagnóstico de pacientes com MPS, através da mensuração da atividade de duas enzimas lisossomais: beta-glicuronidase e arilsulfatase B, deficientes nas MPS VII e VI, respectivamente. Os valores encontrados em indivíduos normais corresponderam aos valores de referência descritos para a doença. Umpaciente com suspeita clínica de MPS demonstrou níveis normais de ambas as enzimas, o que exclui a possibilidade do mesmo possuir MPS VI ou VII. A implantação de protocolos laboratoriais de mensuração enzimática na investigação de MPS permite a realização de diagnósticos mais rápidos e, dessa forma, pode contribuir para as condutas clínicas mais apropriadas.
Subject(s)
Humans , Clinical Protocols , Glycosaminoglycans , Mucopolysaccharidosis VI/diagnosis , Mucopolysaccharidosis VII/diagnosisABSTRACT
Lysosomal storage disorders are a heterogeneous group of biochemical genetic disorders; currently 40-50 are known. The clinical phenotype is determined by the tissue distribution of the storage material and degree of enzyme deficiency. The genetic transmission is mostly autosomal recessive. Lysosomal storage disorders can be divided into three groups according to the major organ system pathology: (1) Primary involvement of the central nervous system without significant somatic or skeletal pathology. Disorders of grey matter, eg gangliosidosis and disorders of white matter eg the leucodystrophy are the most common; (2) Primary involvement of the reticuloendothelial system with or without associated neuropathology, eg Niemann-Pick disease and Gaucher disease; (3) Multisystem involvement in which skeletal manifestations are prominent features. The mucopolysaccharidosis and mucolipidoses are the two major forms with this clinical phenotype. Lysosomal storage disorders identified at Siriraj Hospital are neuronal ceroid lipofuscinosis, GMI gangliosidosis, mucolipidosis II, Maroteaux-Lamy, sialidosis, Sly syndrome, Hunter syndrome, Morquio syndrome, Gaucher disease, Niemann-Pick, Sandhoff disease, Pompe's disease and many more. Most patients came from the provinces where consanguinity is common. Confirmation usually is done by enzyme assays using skin fibroblast culture or leucocytes. Genetic counseling is extremely important and prenatal diagnosis is recommended to high-risk couple.