I am researching a fatty acid amide hydrolase (FAAH) SNP RS324420 and FAAH out microdeletion that together lead to reduced pain sensitivity and reduced anxiety (Moreira et al 2008).
The causative mutations for this new pain insensitivity disorder are: the co-inheritance of (i) a microdeletion in dorsal root ganglia and brain-expressed pseudogene, FAAH-OUT, which we cloned from the fatty-acid amide hydrolase (FAAH) chromosomal region; and (ii) a common functional single-nucleotide polymorphism in FAAH conferring reduced expression and activity. Circulating concentrations of anandamide and related fatty-acid amides (palmitoylethanolamide and oleoylethanolamine) that are all normally degraded by FAAH were significantly elevated in peripheral blood compared with normal control carriers of the hypomorphic single-nucleotide polymorphism. The genetic findings and elevated circulating fatty-acid amides are consistent with a phenotype resulting from enhanced endocannabinoid signalling and a loss of function of FAAH. Our results highlight previously unknown complexity at the FAAH genomic locus involving the expression of FAAH-OUT, a novel pseudogene and long non-coding RNA.
I would like to know, theoretically if CRISPR was used to edit these genes in humans to allow reduced anxiety and pain sensitivity, 'what is the probability that a recurrent mutation would cause the wild-type allele to reemerge in this gene',
