NONE OF YOUR EARWAX

When I was diagnosed with diabetes II and dropped all sugar, white flour, corn syrup, and processed food from my diet -- and I was SERIOUS about it! -- my physiology began to change. It wasn’t just that I dropped fifty pounds, which I did, but also strange small changes developed over the months. Actually, the one I’ve most recently noticed is not strange.

I’ve been a person who had a lot of earwax and bought those little kits with peroxide to fizz around in one’s ear and then a little bulb to wash out whatever has been loosened. Those little bulbs used to turn up around the house in strange places. It’s a remarkably erotic and rather addictive experience to use these kits. But for the last few years I’ve had very little earwax. Until now. It’s come back. Not as much, mind you. I use a q-tip, against all advice, but dip it into hand lotion or something to keep from scratching the ear canal.

My father was always digging in his ears with the mechanical pencil that lived in his shirt pocket with a little notebook. My mother cautioned him constantly against the possibility of something driving that pencil through his ear into his brain, but it never happened. She had a lot of earwax, too, so that now and then she had to go get the doctor to clean out what her hearing aid had impacted against the drum until nothing less than a seismic sound could get through.

One of the characteristics of Native Americans is that they have dry earwax, a kind of powder, as contrasted with Caucasians who have waxy “wet” earwax that can even be used for chapstick. I’ve never figured out a way to get this into a story.

Now I have even more information, thanks to gnxp.com, one of my fav blogs even though I don’t always understand what they are saying. It’s about genetics and uses a lot of math. I read it with my medical dictionary handy, but the stuff is so cutting edge it’s often too new for my dictionary. This latest news is about earwax, breast cancer, and bromodrosis/osmidrosis. That last is fancy talk for “B.O.” Body odor. This phenomenon was discovered by the marketeers just after WWII, I think. Lifebouy soap and all that.

I may not be your best friend, but I’m now prepared to tell you that “one single-nucleotide polymorphism (SNP), 538G>A (Gly180Arg), in the ABCC11 gene determines the type of earwax. The G/G and G/A genotypes correspond to the wet type of earwax, whereas A/A corresponds to the dry type.” So on the long wound-up double helix, one little gene has a short section (an SNP or “snip”) that varies from person to person in an inherited way (polymorphic=many formed) and this what decides whether you have earwax or not, stink or not, or might be inclined to breast cancer or not. My father was a smelly man. My mother had breast cancer. Me? Come a little closer.

The good news is: “For rapid genetic diagnosis of axillary osmidrosis and potential risk of breast cancer, we developed specific primers for the SmartAmp method that enabled us to clinically genotype the ABCC11 gene within 30 min.”

If you want the scientific details, get out your own medical dictionary: “We herein provide the evidence that this genetic polymorphism has an effect on the N-linked glycosylation of ABCC11, intracellular sorting, and proteasomal degradation of the variant protein. Immunohistochemical studies with cerumen gland-containing tissue specimens revealed that the ABCC11 WT protein was localized in intracellular granules and large vacuoles, as well as at the luminal membrane of secretory cells in the cerumen gland, whereas granular or vacuolar localization was not detected for the SNP (Arg180) variant. This SNP variant lacking N-linked glycosylation is recognized as a misfolded protein in the endoplasmic reticulum and readily undergoes ubiquitination and proteasomal degradation, which determines the dry type of earwax as a mendelian trait with a recessive phenotype.”

The variation in earwax seems to conform pretty closely to that of EDAR which is the name of a gene. “This gene encodes a member of the tumor necrosis factor receptor family. The encoded transmembrane protein is a receptor for the soluble ligand ectodysplasin A, and can activate the nuclear factor-kappaB, JNK, and caspase-independent cell death pathways. It is required for the development of hair, teeth, and other ectodermal derivatives. Mutations in this gene result in autosomal dominant and recessive forms of hypohidrotic ectodermal dysplasia.” (Thank goodness for Google and cut-and-paste.)

“While the populations of Europe and Africa have wet ear wax, those of East Asia have dry ear wax. Other populations are somewhere in between. Nature Genetics has the original paper (don't be surprised if the link takes a while to load).”

There doesn’t seem to be any particular survival advantage in the nature of one’s earwax, unless one generates enough of it to be deafened, but since “earwax type and armpit odor are correlated, populations with dry earwax, such as those of East Asia, tend to sweat less and have little or no body odor, whereas the wet earwax populations of Africa and Europe sweat more and so may have greater body odor.” Razib, whose blog this is, remarks: “The adults I have known who do not need to make recourse to deodorants to ward off body odor have all been East Asian females. No surprise.”

So now I’d be curious to know about geographical rates of breast cancer and their correlation, which clearly involve survival value. And maybe lack of body odor has some advantages in tiger country. American Indians (esp. those in the seventh grade who have recently discovered deodorants) complain about the smell of Euros, which fits this, while the idea that “squaws” smell bad is clearly unjustified. For population scientists, this “allele” (genetic section) is an interesting way to track population migrations. In fact, perhaps those who claim to be genetic Native Americans (as opposed to pedigree-certified, the federal legal standard now) will be asked to pass a “sniff test.” Of course, they might be mongolian.