RESUMO
La galactosialidosis (OMIM #256540) es una enfermedad metabólica lisosomal causada por mutaciones en el gen CTSA, que codifica la proteína protectora catepsina A. La pérdida de función de dicha proteína causa, secundariamente, un déficit combinado de dos enzimas, beta-galactosidasa y neuraminidasa. Se expone el caso de un paciente que presentó manifestaciones clínicas compatibles con el subtipo infantil tardío de galactosialidosis. El análisis bioquímico mostró déficits de las dos enzimas implicadas, mientras que el estudio molecular reveló dos mutaciones: una nueva mutación nunca antes descrita, p.His475Pro (c.1424 A>C), y una mutación previamente reportada, p.Arg441Cys (c.1321C>T), localizadas en los exones 15 y 14, respectivamente.
Galactosialidosis (OMIM #256540) is an autosomal recessive lysosomal storage disorder caused by mutations in the CTSAgene, which encodes the protective protein cathepsin A. The loss of function of this protein causes a secondarily deficiency of beta-galactosidase and N-acetyl-α-neuraminidase enzymes activities. We describe the clinical, biochemical and molecular analysis of a case report with a phenotype compatible with the late infantile form. The biochemical analysis reveled deficiencies of beta-galactosidase and neuraminidase activities in dried blood spot and fibroblasts and the molecular study showed two missense mutations in the CTSA gene: a previously reported mutation, p.Arg441Cys (c.1321C>T), and a novel mutation, p.His475Pro (c.1424 A>C), located in exons 14 and 15, respectively.