Another promising option for the treatment of hemophilia A is the introduction of patient-derived induced pluripotent stem cells (iPSCs). The defective gene can be corrected in iPSCs by using programmable nucleases like zinc ginger nucleases (ZFNs) [2-5], transcription activator-like effector nucleases [6-8] and clusters of regularly interspaced palindromic repeats [9-16]. In case of these programmable nucleases they cleave the chromosomal DNA in a targeted manner and produce DNA double stranded breaks. The nick will be repaired by endogenous mechanisms known as homologous recombination or non-homologous end-joining. Finally, it will result in the correction mutagenesis such as deletions [17,18], duplications and inversion [19]. These gene-corrected iPSCs are then allowed to differentiate into appropriate somatic cells before delivery to patients to ensure the expression of the functional gene.

Challenges of the technology

iPSCs have their own merits and demerits. Though iPSCs are mentioned to be the cells that will rule the future medical industry to provide patient-specific stem cells [20-22], there are controversies over its application to human subjects [23,24]. Challenges are encountered with the recent advancements which can harness its true activity for biomedical research to successfully formulate effective therapeutic approach [25]. It is worth to estimate the potentials of iPSCs as they are quite prominent being the readily accessible such as skin or blood which are enough to generate the disease-specific models. Existing challenges include the kinetics of disease onset and progression and also the spatial localization of the disease to create disease models which are commented can be tackled with advanced strategies such as gene modification, biomaterials, reprogramming etc. [26]. Researchers have been already working to correlate hemophilia A using patient-specific iPSCs because of its unlimited self-renewal and differentiation capabilities [27-31].