Genes replacement therapy

Although much progress has been made in gene replacement therapy, significant challenges remain. These include ... 

For loss-of-fundion mutations gene replacement therapy usng retroviruses, adenoviruses, adeno-associated viruses, or liposomes as vectors... 

Gene replacement therapy for loss of function mutations... 

Gene replacement therapy should be possible in both ADA and PNP deficiency, and such a trial was attempted with two patients having ADA deficiency. The patient s T cells were removed and a normal ADA gene was inserted into the T cells by means of a retroviral vector. The modified T cells were reintroduced into the patient s bloodstream. Patients were followed for clinical improvement while they continued to receive PEG-ADA treatment. No permanent cure was achieved. 

In contrast to enzyme replacement therapy, one study of gene replacement therapy of a patient with mucopolysaccharidosis, type II, Himter syndrome, did not show any benefit [10], While this is discouraging at present this may be modified for future trials and may prove to be successful. 

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