RESUMO
Molecular analysis and clinical updates are provided on a previously reported mother and adult son with Gaucher disease; two other children died with acute neuronopathic (type 2) Gaucher disease. The mother and son have the identical genotype (370/444) but very different clinical manifestations. These findings illustrate the need for additional studies before families with newly diagnosed Gaucher disease undergo counseling.
Assuntos
DNA/análise , Doença de Gaucher/genética , Mutação , Adulto , Alelos , Sequência de Bases , Feminino , Doença de Gaucher/diagnóstico , Amplificação de Genes , Aconselhamento Genético , Genótipo , Heterozigoto , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Estrutura Molecular , beta-Glucosidase/genéticaRESUMO
Galactocerebrosidase (GALC) is responsible for the lysosomal catabolism of certain galactolipids, including galactosylceramide and psychosine. Patients with GALC deficiency have an autosomal recessive disorder known as globoid cell leukodystrophy (GLD) or Krabbe disease. Storage of undegraded glycolipids results in defective myelin and the characteristic globoid cells observed on pathological examination of the central and peripheral nervous systems. Most patients have the infantile form of GLD, although older individuals are also diagnosed. Recently the human, mouse, and canine GALC genes were cloned, and mutations causing GLD have been identified. We now describe the construction of a vector containing human GALC cDNA (MFG-GALC), and the transduction of cultured skin fibroblasts from molecularly characterized Krabbe disease patients, as well as rat brain astrocytes and human CD34(+) hematopoietic cells, using retrovirus produced by the psi-CRIP amphotropic packaging cell line. The transduced fibroblasts showed extremely high GALC activity (up to 20,000 times pretreatment levels, about 100 times normal). GALC was secreted into the media and was taken up by untransduced fibroblasts from the same or a different patient. Mannose-6-phosphate receptor-mediated uptake was only partially responsible for the efficient transfer of GALC to neighboring cells. Additional studies confirmed the presence of normal GALC cDNA and mRNA in the transduced cells. The GALC produced by the transduced cells and donated to neighboring untransduced cells was localized to lysosomes as demonstrated by the normal metabolism of [14C]stearic acid-labeled galactosylceramide produced from endocytosed [14C]sulfatide.