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Completed

NCT Number: NCT01462448

Study to Identify the Genetic Variations Associated With Phantom Limb Pain

The purpose of this study is to determine if there is a genetic component to phantom limb pain. DNA will be analyzed for single nucleotide polymorphisms (SNPs) between the control and phantom limb pain group. Total RNA will also be isolated and profiled to asses the degree to which our gene(s) of interest are expressed in the presence or absence of phantom limb pain. Some proteins, such as inflammatory antibodies or the neurotrophin brain-derived neurotrophic factor (BDNF), will also be assessed for their association(s) with phantom limb pain.

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Key information

Conditions

Phantom Limb Amputation, Traumatic Nervous System Diseases Neuritis Neurobehavioral Manifestations Neurologic Manifestations Neuromuscular Diseases Pain Pain, Postoperative Pathologic Processes Pathological Conditions, Signs and Symptoms Perceptual Disorders Peripheral Nervous System Diseases Postoperative Complications Signs and Symptoms Wounds and Injuries

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Walter Reed National Military Medical Center (WRNMMC)

Bethesda, Maryland, 20889, United States

About this study

Most patients (90-95%)with major limb amputations experience a phantom limb--the vivid impression that the limb is still present. In many cases, the sensation is painful for reasons that are currently not well understood. A small subset of amputees (<10%) never experience phantom limb pain (PLP), the painful sensation felt in the amputated limb. This difference suggests that there may be a genetic component that precludes some patients from ever experiencing PLP. Understanding the genetic components of PLP may help in predicting which patients will experience PLP and which amputees will respond to the various treatment options available.

In order to understand the genetic aspects and ultimately develop more effective treatment options in the future, patients with and without PLP will be asked to give 30 mls of blood after overnight fasting. These blood samples will be de-identified and sent to the National Institutes of Health (NIH) in Bethesda, Maryland, where all of the genetic analyses will take place.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Chronic PLP Group:

  • At least 18 years of age.
  • Written informed consent and written authorization for use or release of health and research study information
  • Single or multiple upper and/or lower limb amputation
  • At least three months post-amputation
  • Ability to follow study instructions and likely to complete required visit(s)
  • Experienced PLP for at least one month and at least 3 times per week
  • Phantom limb pain differentiated from residual limb pain by physical exam.
  • Subjects taking blood thinners or other medications that do not increase risk during a blood draw.

Non-Chronic PLP Group:

  • At least 18 years of age.
  • Written informed consent and written authorization for use or release of health and research study information
  • Single or multiple upper and/or lower limb(s) amputation
  • At least three months post-amputation
  • Ability to follow study instructions and likely to complete required visit(s)
  • Experienced PLP less than 10 times total and/or for less than two weeks
  • Subjects taking blood thinners or other medications that do not increase risk during a blood draw.

Treatment and study plan

Blood draw

Procedure

Single blood draw of 30 ml

Other names: Venipuncture

Primary outcomes

  1. Identification of Unique Single Nucleotides Polymorphisms (SNPs) associated with Phantom Limb Pain (PLP)

    Time frame: 5 years

    The primary outcome measure for this study is the identification of unique SNPs that may correlate with PLP. Patients will undergo a one-time blood draw and fill out a survey characterizing their phantom limb pain. The PLP characteristics along with DNA analysis using Affymetrix SNP chip technology will be used to match genotype with phenotype.

Secondary outcomes

  1. Correlation between Phantom Limb Pain (PLP) and Blood Levels of Antibodies Associated with Peripheral Nerve Damage

    Time frame: 5 years

    The underlying hypothesis of the secondary outcome measure is that damage to peripheral nerves provokes a humoral immune response to neuronal and glial proteins that can be detected by measuring specific antibodies in blood. The data obtained will lead to a more complete understanding of pathogenic mechanisms in PLP and potential biomarkers for sub-classification, prognosis, and intervention.

  2. Correlation between Phantom Limb Pain (PLP) and Serum Levels of Brain-derived Neurotrophic Factor (BDNF)

    Time frame: 5 years

    BDNF has been implicated in pain nociception and is therefore pertinent to our study of phantom limb pain. After peripheral nerve injury, BDNF expression is dramatically increased in pain receptors of the brainstem.

  3. Correlation between Phantom Limb Pain (PLP) and Unique Transcribed RNA

    Time frame: 5 years

    Many underlying causes for neuropathic pain involve changes in messenger ribonucleic acid (mRNA) levels because of altered gene expression or transcript stability. The study will isolate total RNA from blood and measure the relative amounts of transcribed RNA under the condition of phantom limb pain or no phantom limb pain.

Sponsors and collaborators

Lead sponsor

Henry M. Jackson Foundation for the Advancement of Military Medicine

Other

Collaborators

  • Uniformed Services University of the Health Sciences

Registry information

Important dates

Study start
2012
Primary completion
2014
Study completion
2023
First posted
Oct 31, 2011
Registry last updated
Aug 12, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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