Induced pluripotent stem cells offer opportunities for personalized cell replacement therapy due to unlimited self renewal potential and ability to differentiate into different somatic cells. Autologous cell replacement therapy gives opportunity for therapeutic applications with uses of induced pluripotent stem cell technology. As known autologous induced pluripotent stem cells are genetically identical to donor cells. Therefore these cells and their cellular derivatives are not expected to be immunologically rejected. Since 90s, a lot of new technologies have been evolved in molecular biology and genetics. By using these technologies, so many genetic variations have been identified which significantly increase the risks and causes of neurodegenerative diseases in patients. An induced pluripotent stem cell obtained from a fully differentiated cell of a patient carries same mutations in genome which causes disease. Unfortunately, these mutations reduce the dedifferentiation ratio in obtaining induced pluripotent stem cells in laboratory conditions. Also, these mutations affect on induced pluripotent stem cell viability and growth. So, gene correction studies are needed before induced pluripotent stem cell technology for having optimal results in cell replacement therapy. Here in this review, new approaches in gene correction studies including homologous recombination technique were mentioned. The role of direct transdifferentiation technique was explained in obtaining a cell which can be used in replacement therapy successfully. New cell replacement therapy applications were defined especially in neurodegenerative diseases. It seems that, these advanced technologies will be applied widely in permanent therapy of neurodegenerative diseases in recent future.

Keywords: Cell replacement therapy, induced pluripotent stem cells, neurodegenerative diseases, gene correction, homologous recombination, direct reprogramming