Identification of the promoter region and gene expression for human acid alpha glucosidase

Genetic deficiency of acid alpha glucosidase (GAA) results in glycogen storage disease type II. A cDNA containing the complete coding region was constructed and cloned into the expression vector pSV2 and was transiently transfected into an SV40 immortalized GAA deficient human fibroblast cell line which has undetectable levels of GAA enzyme activity and does not express GAA mRNA. Transfected cells had 4.9% of normal human fibroblast enzyme activity. Additionally a 5' 1.8 kb genomic fragment was ligated to the 5' end of the GAA cDNA construct and cloned into pUC19. Transient and stable transfection also resulted in expressed GAA enzyme activity in deficient fibroblast cells, indicating that the genomic fragment has GAA promoter function.