Abstract: The present invention relates to a transcription factor EB (TFEB) protein, ortholog, recombinant or synthetic or bio technological functional derivative thereof, allelic variant thereof and fragments thereof; a chimeric molecule comprising the TFEB protein, ortholog, recombinant or synthetic or biotechnological functional derivative thereof, allelic variant thereof and fragments thereof; a polynucleotide coding for said protein or ortholog, recombinant or synthetic or biotechnological functional derivative thereof, allelic variant thereof and fragments thereof; a vector comprising said polynucleotide; a host cell genetically engineered expressing said polypeptide or a pharmaceutical composition for use in the treatment or/and prevention of a glycogen storage disease. Preferably of Pompe or Danon disease.

Abstract: The present invention relates to an allosteric non-inhibitory chaperone of the lysosomal acid alpha-glucosidase (GAA) for use in the treatment of a pathological condition characterized by a deficiency of the lysosomal acid alpha-glucosidase (GAA), to pharmaceutical composition thereof, to a method for increasing the activity of GAA in a subject and to a method for identifying an allosteric non-inhibitory chaperone for GAA.