KARACHI, Oct.28: People who tolerate pain better may just be blessed with better genes. Scientists say levels of a molecule called BH4, required for the production of major neurotransmitter chemicals, influence the body’s sensitivity to pain.

The team of international researchers, based at Massachusetts General Hospital, Boston, say BH4 levels might also determine a person’s vulnerability to chronic pain.

Reporting in the latest online issue of Nature Medicine, they found that a certain set of variations in a gene that is involved in producing BH4 appear to reduce a person’s pain sensitivity.

“This is the first evidence of a genetic contribution to the risk of developing neuropathic pain in humans. The pain-protective gene sequence, which is carried by about 25 per cent of the population, appears to be a marker both for less pain sensitivity and a reduced risk for chronic pain,” Dr Clifford Woolf, director of the neural plasticity research group at MGH, said.

“Identifying those at greater risk of developing chronic pain in response to medical procedures, trauma or diseases could lead to new preventive strategies and potential treatment,” he said.

In research involving hundreds of volunteers, the scientists concluded that people with a protective GCH1 haplotype -- a set of variations in the gene that are inherited together – were less sensitive to pain. This GCH1 haplotype reduces production of BH4.

“Our results tell us that BH4 is a key pain-producing molecule. When it goes up patients experience pain, and if it is not elevated they will have less pain,” Dr Woolf said.

He stated that the data also suggested that individuals who claimed that they felt less pain were not just stoics but genuinely inherited a molecular machinery that reduced their perception of pain.—PPI