Answer:
Polymorphism of the gene of metabolizing enzymes.
Step-by-step explanation:
Polymorphism may be defined as the phenomena of occurence of the same genetic material in the different forms.The multiple forms of the single gene is known as gene polymorphism.
The single nucleotide polymorphism shows the genetic polymorphism. The individuals has the different affect against the same drug. This mainly occur due to the polymorphism or multiple forms of the allele of the same gene that metabolize the drugs.