Table 1.

The fundamental experimental approach for gene therapy used four theoretical modes of action [56].

Sl no.	Modes of Action	Specification
1.	Gene replacement [57]	This is done when the disease is caused due to the loss of functionality of the gene.
2.	Gene knockdown [58]	This is employed when a function has been toxically increased or when gene metabolites or gene products have accumulated.
3.	Pro-survival or symptomatic gene therapy [56]	Here the pathological condition is reversed by using a pro-survival gene that is non-specific in nature.
4.	Cell suicide gene therapy [59]	This is typically thought of as the last option. This is primarily used in cancer treatment, where it is necessary to eradicate malignant cells. In the case of KAND, this method’s application is constrained.