Re: can the gene being used in gene therapy disrupt a vital housekeping gene ?

In gene therapy, the aim is normally for a mutated or damaged gene to be replaced by the therapeutic gene in a controlled way. The subject is really very complex as there are different ways of approching the insertion of the gene and it depends upon whether the target cells are mammalian, bacterial etc. It would all depend upon the design of the individial experiment but I'll try to give you a little to perform a more specific internet search for info. The best thing you could do would be track down a review article on gene therapy.

If random integration was the aim then it would be possible for the gene to disrupt other genes in many possible ways. e.g. the gene could insert within the housekeeping gene, resulting in an incorrect sequence for the protein product. Alternatively a randomly inserted gene could disrupt the upstream control elements. However, in gene therapy the aim is generally to replace a faulty gene in a controlled way e.g. by swapping them around (the gene being targetted by a complimentary target sequence) or for the gene to be temporarily expressed to provide a product which is not being made in a mutated cell (e.g. in a plasmid vector). If you search for key terms such as gene therapy vectors; neo cassettes; mammalian gene therapy; targetted integration and tissue specific gene expression for a start then you should find useful information for your talk.