Soldiers with certain gene variations more likely to develop chronic pain after amputation

Researchers have identified hundreds of variants in a patient’s DNA sequence or genetic code that predict which military service members are more likely to develop persistent, chronic pain after amputation, according to a study presented at the ANESTHESIOLOGY™ 2013 annual meeting. 

As many as 80 percent of all amputees experience pain in their residual limb, or a “phantom pain,” where they feel pain in the part of the limb that is missing, according to the Journal of the International Association for the Study of Pain. From 2000 to 2011, there were 6,144 amputations among 5,694 injured service members, according to the Armed Forces Health Surveillance Center. More than one-third had major amputations, defined as the loss of a hand, foot or more.

“Traumatic amputations of limbs profoundly change the lives of affected military service members,” said Andrew D. Shaw, M.D., associate professor of anesthesiology and critical care medicine, Duke University Medical Center, Durham, N.C. “Persistent phantom pain after amputation is a serious problem with no effective treatments. By identifying these ‘pain genes,’ we may be able to discover the reasons why pain occurs and predict which patients are more likely to have it. In the future, we hope to discover the biology of persistent pain and develop ways to combat it.”

In the study, blood was collected for DNA, RNA and plasma extraction from 49 service members who had amputations and persistent pain. These blood samples were then mapped using Exome Sequencing technology to identify any variations the military service members have in common.

Hundreds of new DNA sequence variations previously unknown were identified as pathways of biological importance as the possible source of chronic, persistent pain for service members, according to the study.

“This is one of the first studies where ‘pain genes’ have been identified in humans using next-generation sequencing,” explained Dr. Shaw. “We have known about some of them in lab studies. Now that we have identified these gene variations, we need to study them and then create new medicines to prevent and relieve the chronic pain for these patients.”