New studies suggest that genetic backgrounds may be to blame for smokers that have a hard time quitting or cutting down on their habit.

Several genes can dictate how prone you are to take up smoking or how easily you can quit, based on the studies.

In three separate studies that collected data from 140,000 people, scientists identified that there are three genetic mutations that increase the number of cigarettes people smoke a day.

A common single-letter change was found in the genetic code that lies in parts of the DNA molecule that contain genes that influence nicotine addiction and lung cancer risk.

However, any potential benefits from the research still have a long way in the future, said Amanda Sandford, lead research at Action on Smoking and Health (ASH).

"Smokers who want to quit should not wait for treatment tailored to their genetic make-up," Sandford said.