It remains me of the article I read a long time ago about a person who joined Eskimos in remote location over the winter. He started to eat only the extremities of the seals – and became sick due to vitamin deficiencies. Eskimos told him “you need to eat the whole animal as the animals live in the natural environment and are not deficient in anything”. So he reluctantly started to eat all animal parts and on his return the doctor’s examination showed that his health was in perfect order. – This reminds me of my childhood living in the communist country. My parents did not want to become communists so my father was punished for that. For that reason money were not plentiful. During the communism the vegetables or fruit were non existent for at least 9 months/year except for an occasional cabbage and potatoes. I was always wondering why we were in a very good health. No wonder => my mum on a very low budget had to buy a cheep meat consisting of many animal organs. I just wonder how healthy were the communists who had enough money to buy the steaks but could not buy the vegetables/fruit anyway as there were none.
The genotype variation specifically refers to the Rs4680 SNP , which is one of the SNPs that services like 23andMe test for. So someone could sign up for 23andMe testing and only start buying modafinil if the results are favorable; considering that 23andMe sometimes holds sales at $100 or $200 and that one could easily spend this much on a single order of modafinil, testing first may not be a bad idea. But on the other hand: anecdotes are hard to come by of people who have used modafinil, been genotyped, and checked that SNP, yet I have been told by 2 Val/Val users that sublingual Modalert/Waklert did nothing for them (personal communication; 2 ) and by 4 Met/Met users that modafinil worked for them and there are 2 further anecdotes on Hacker News & Reddit ( 1 , 2 , multiple ). Besides the dubiousness of such a large effect size from a single SNP, candidate-gene results frequently disappear ( Ioannidis et al 2011 ), like what happened when 12 highly cited IQ-related SNPs failed to replicate in a well-powered 2011 GWAS and subsequent GWASes (replication being the coin of science ). As of 23 May 2013, there do not seem to have been any followup citing studies of this SNP association. Given the weakness of the evidence, one would probably have to be on the razor’s edge of deciding to try or not try modafinil before your result would make the difference.