Genetics of pain Flashcards
What are microRNA
Short non coding RNA which play a role in regulation of gene expression in disease processing
What is fibromyalgia
Chronic pain condition
What gene is involved in fibromyalgia
BDNF gene
What affect the levels of the BDNF gene expression
Micro RNA changes in microglia and in dorsal root ganglion neurons
What is BDNF involved in
Neuron survival, growth and neuroplasticity
How is BDNF involved in pain
Nervous system injury increases expression and secretion of BDNF
BDNF initiates neuronal repair yet causes pain
BDNF reduces inhibitory synaptic transmission in the dorsal horn
Painful stimulation increases BDNF expression in the spinal dorsal horn and brainstem leading to hyperalgesia and the development of tactile allodynia (pain in absence of a painful stimulus) through enhanced BDnF signalling
Does fibromyalgia run in families
Yes
What mutation do those with ‘man on fire’ syndrome have
SCN9A gene
this gene encodes the Nav1.7 channel which Is involved in propagating electrical signals along nerves. In this syndrome, the Nav1.7 channel is hypersensitive to stimulus
What are the Nav1.7 channels like in those who can’t experience pain
Truncated, non-functional
What is another mutation which causes pain insensitivity
Mutation which confers reduced expression and activity of the FAAH enzyme which is an enzyme in the endocannabinoid system
What does the endocannabinoid system modulate
Pain Mood Inflammation Appetite Cognition
Side effects of opioids
Constipation Nausea Anti-tussive effects Drowsiness Dizziness Low blood pressure Physical addiction Bronchospasms Hives Respiratory depression
What effects does being a poor metabolisers of CYP2D6-dependent analgesic prodrugs such as codeine have
Decreased activation of the drug
What happens when ultra-rapid metabolisers of CYP2D6-dependent analgesic prodrug codeine
Have potential for increased production of morphine from codeine thus have a greater risk for opioid related adverse events and might benefit from lower dose
