What
@Valentijn keeps confusing is Allele Frequency and Genotype Frequency.
I know the difference.
While any SINGLE allele may be common, the Genotype, meaning the combination of the TWO allele may be less common even though the single allele is common. And I feel this is why she thinks every genotype is "common" and does not matter.
In fact, when we look at the Genotype distribution of rs1799836 we can see that Valentjn is absolutely wrong, that in fact, AG is the LEAST common genotype even though both of those alleles are common.
Seriously? Fine. For WOMEN, of which the poster is one, the heterozygous type is by far the most common. And 49.6% of women are heterozygous with CT, while 29.5% are homozygous with TT, and 20.9% are homozygous for CC. The heterozygous CT variation is by far the most common variation for females with two X chromosomes.
And of course, 45.7% of men are hemizygous for C and 54.3% of men are hemizygous for T, but I'm not sure why you think that is pertinent. Perhaps you could explain why you think hemizygous male variations are at all relevant in the current thread, where a female forum member was asking for information about her specific situation? Personally I find it preferable to stay on point and avoid detailed information which is completely irrelevant to the questions being asked.
I would not say that what looks like an 18% Genotype distribution is common.
Well, as long as SNPedia is your primary source of information, don't expect to get an in-depth understanding of anything. At any rate, the heterozygous version is the most moderate. Not "fast", and not "slow". And even if it were the slow or fast homozygous or hemizygous versions, that wouldn't mean a helluva lot. The body manages to cope pretty well with either version, as evidenced by the billions of people walking around without any obvious problems.
And ... 18% of 7 billion people actually is very common. That's in excess of 1.26 billion people.
Pain sensitivity in fibromyalgia is associated with catechol-O-methyltransferase (COMT) gene
http://onlinelibrary.wiley.com/doi/10.1002/j.1532-2149.2012.00153.x/abstract
According with previous research, our findings revealed that haplotypes of the COMT gene and genotypes of the Val158Met polymorphism play a key role on pain sensitivity in FM patients.
1) Don't quote a paper unless you have full access to it. Abstracts give a partial picture at best, and it's often a misleading one. 2) You forget to mention this bit, which says that only those homozygous for the met
I want to say as well that it is curious to me that she choose to focus on those that particular COMT SNPs and left the rest out. Because if she looked at ALL the COMT SNPs when would see the relevance, ie rs4680 above.
And for MAOB rs1799836,
Genetic Variants of Neurotransmitter-Related Genes and miRNAs in Egyptian Autistic Patients
http://www.hindawi.com/journals/tswj/2013/670621/
Plasma MAOB activity was significantly reduced in G than in A allele carrying males.
But why do I look at these genes in CFS and FM? Because the researchers do as well:
A comparison of classification methods for predicting Chronic Fatigue Syndrome based on genetic data
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2765429/
Candidate genes
In the present study, we only focused on the 42 SNPs as described in Table Table22[18]. As shown in Table Table22[18], there were ten candidate genes including COMT, corticotropin releasing hormone receptor 1 (CRHR1), corticotropin releasing hormone receptor 2 (CRHR2), MAOA, MAOB, NR3C1, POMC, solute carrier family 6 member 4 (SLC6A4), tyrosine hydroxylase (TH), and TPH2 genes. Six of the genes (COMT, MAOA, MAOB, SLC6A4, TH, and TPH2) play a role in the neurotransmission system [8]. The remaining four genes (CRHR1, CRHR2, NR3C1, and POMC) are involved in the neuroendocrine system [8]. The rationale of selecting these SNPs is described in detail elsewhere [8]. Briefly, most of these SNPs are intronic or intergenic except that rs4633 (COMT), rs1801291 (MAOA), and rs6196 (NR3C1) are synonymous coding changes [8].[/QUOTE]