The researchers at Liverpool specifically looked at the role the gene plays in communication between cells in the nervous system.
"We used the nematode worm as a model to look at the role genes play in alcohol tolerance because all of the worm's genome has been characterised and we can therefore identify its genes easily," said Professor Bob Burgoyne, Head of the University's School of Biomedical Sciences
"The gene we looked at corresponds to a gene in humans that performs the same function in the nervous system. Mutations in genes can occur naturally without any known cause and will persist if they are not particularly harmful," he added.
The naturally occurring gene specifies the ways in which amino acids arrange themselves into a protein called UNC-18 - or Munc18-1 in humans, an essential component of the nervous system.
They found that this gene can a change the nature of one of the amino acids, which then alters communication between cells in the nervous system.
As a result of these changes the nervous system becomes less sensitive to the effects of alcohol, allowing the body to consume more.
"Alcohol consumption can affect the nervous system in a number of ways. Low concentrations of alcohol can make the body more alert, but high concentrations can also reduce its activity, resulting in motor dysfunction and a lack of coordination," said Burgoyne.
"Some people, however, are more susceptible to these effects than others, but it has never been fully understood why this is," he added.
The research is published in Molecular Biology of the Cell.