Thanks to Genes-This woman in Scotland has no pain sensitivity, lives Pain free

Thanks to Genes-This woman in Scotland has no pain sensitivity, lives Pain-free.

The woman can feel virtually no pain due to a mutation in a previously unidentified gene, according to a research paper co-led by UCL. Scientists have now found a new gene target, FAAH gene pointed out to be a novel pain killer discovery that could potentially offer post-surgical pain relief and also accelerate wound healing.

She also experiences very little anxiety and fear and may have enhanced wound healing due to the mutation, which the researchers say could help guide new treatments for a range of conditions. It is a novel case of a woman who co-inherited microdeletion and FAAH hypomorphic SNP allele, making her pain deficit and she has an extremely low level of anxiety and fear. The case was published in the British Journal of Anesthesia.

Please also read -Man who feels no pain- a medical condition “Congenital insensitivity to pain”

A 66-yr-old Caucasian female presented to Raigmore Hospital in Inverness, Scotland for orthopaedic surgery, specifically a trapeziectomy with ligament reconstruction and tendon interposition and extensor pollicis long realignment after a diagnosis of bilateral pantrapezial osteoarthritis. There were significant deformity and deterioration in the use of the right thumb, which was reported as painless before the operation. The pre-assessment note classed her as ASA physical status. But highlighted that she had a history of vomiting after intake of morphine.

The doctors were extremely shocked when they observed that after the operation, her pain intensity score was 0/10 until the next day when she was discharged home. The only postoperative analgesic she received in the hospital was paracetamol 1 g i.v. in the PACU on the day of her surgery.

Extraordinarily, she required no postoperative analgesics other than paracetamol for this known painful surgery (trapeziectomy), even after the axillary nerve block had worn off. She showed no pain from pinching or from peripheral i.v. cannula manipulation, which led to further investigations.

She does not take any medication at present and is fit and active with no medical conditions apart from arthritis. Apart from pain insensitivity, she has an extraordinary optimistic outlook.

On the Generalized Anxiety Disorder-7 anxiety questionnaire taken at age 70, she scored 0/21, classified as mild (the lowest category). Likewise, on the Patient Health Questionnaire-9 for depression, she scored 0/29, classified as mild. She reported long-standing memory lapses (e.g. frequently forgetting words mid-sentence and placement of keys). She also reported never panicking, not even in dangerous or fearful situations, such as in a recent road traffic accident.

She was referred to UCL and the University of Oxford, for pain genetic testing which revealed that she has two notable mutations, a microdeletion in dorsal root ganglia and brain-expressed pseudogene, FAAH-OUT and a common functional single-nucleotide polymorphism in FAAH conferring reduced expression and activity.

Fatty-acid amide hydrolase (FAAH) is the major catabolic enzyme for a range of bioactive lipids called fatty-acid amides (FAAs). These FAAs include N-acyl ethanolamines, such as anandamide (AEA), that act as endogenous ligands for cannabinoid receptors. Por studies done on mice have shown that FAAH knockout mice, as well as animals treated with FAAH inhibitors, are severely impaired in their ability to hydrolyze AEA as well as a variety of noncannabinoid lipid signaling molecules and consequently possess greatly elevated levels of these endogenous ligands resulting into anti-inflammatory and pain deficit phenotypes.

FAAH knockout mice have reduced pain sensation, accelerated wound healing, enhanced fear-extinction memory and reduced anxiety. Thus, targeting this gene could be a boon in planning treatments for pain relief and enhanced wound healing.

"People with rare insensitivity to pain can be valuable to medical research as we learn how their genetic mutations impact how they experience pain, so we would encourage anyone who does not experience pain to come forward," said Dr Cox.