People who are prone to reckless behaviour when drunk are likely to carry a genetic mutation that leads them to impulsive and irresponsible actions while under the influence of alcohol, scientists from the University of Helsinki have said.

In a case study looking at their own nation, the researchers found that more than 100,000 Finns were born with the mutation, which they believed was present from birth, as opposed to developing in later life, as its permanence implied it was the result of biological factors.

The study outlined a mutation in the gene of the serotonin 2B receptor which could lead to reckless behaviour when drunk.

"The results also indicate that persons with this mutation are more impulsive by nature even when sober, and they are more likely to struggle with self-control or mood disorders," said lead researcher and psychiatrist Roope Tikkanen.

The report, which was published in the journal Translational Psychiatry, said that although not a lot was known about the serotonin 2B receptor and the purpose it served in humans, it was to be linked to impulsivity – a typical trait in many mental health disorders. Researchers said the mutation was present in 2.2% of the Finnish population.

"The impact of one gene on complex phenomena is typically minor. But it is possible to identify the impact of such a genetic mutation in the Finnish population, as our historical isolation has led to a relatively homogenous gene pool," Tikkanen said.

The researchers said that if the results from the relatively small trial proved significant in larger tests, it could have implications on those who suffered from impulse control, particularly if measures to limit alcohol were taken.

"Other measures would include attempting to achieve control over behaviour through cognitive-behavioural psychotherapy or medication," they said.