Gene clues to risky lifestyles

Some people may inherit versions of genes that make them more likely to adopt a lifestyle that increases their risk of developing cancer, a new study suggests. The findings, published in the journal Molecular Psychiatry, show that some gene variants may make a person more anxious or depressed, and so perhaps more likely to drink alcohol, smoke or take drugs. Study leader Marcus Munafo, of the Cancer Research UK (CRUK) GP Research Group at Oxford University, said that the work might help target different people in different ways with healthy living campaigns.

The researchers combined the results of 46 previous studies linking several genetic variations to personality traits. They identified two genes that appear to be involved in susceptibility to a 'risky' lifestyle: the human serotonin transporter gene, 5HTT-LPR and the dopamine receptor gene, D4R. Data from over 20,000 people showed that a shorter version of the 5HTT-LPR gene is linked to a more anxious, neurotic personality, while a particular variant of D4R is associated with a more outgoing character. The 5HTT-LPR variant could affect levels of serotonin, a brain chemical involved in mood, while D4R could affect a person's response to another brain chemical, dopamine, which is linked to pleasure-seeking behaviour. 'Our study suggests that there's a genetic basis to certain kinds of personality trait, which may be important in influencing whether people take up habits like smoking or whether they can give them up' claims Munafo. But he stressed that genes affecting anxiety levels were only part of the story: non-genetic factors such as childhood experiences and diet also have a large influence on how genes are expressed.

Robert Souhami, CRUK's head of clinical research, said that 'around half of all cancers are potentially preventable if people were to alter their lifestyles, so finding ways of changing behaviour is one of our key priorities'.