What is the gene for smelly armpit?
The underarm body odor has been linked to a gene called ABCC11, which encodes a protein that transports molecules across cellular membranes, including molecules in the sweat. If the ABCC11 gene is non-functional, sweat molecules are unable to cross the membrane barrier to reach the armpit.
Two percent of people carry an unusual form of a specific gene (ABCC11) that means their armpits never smell. The finding came from new research involving 6,495 women who are enrolled in the Children of the 90s study at the University of Bristol, England, and was published in the Journal of Investigative Dermatology.
The gene variant is known as ABCC11 and the study authors said that the consistency of earwax is a good indication of those who have it. People who have dry earwax as opposed to sticky earwax are highly likely to have the ABCC11 variant and therefore do not produce under arm body odour.
East Asian and Native American people were already known to have a form of the ABCC11 gene that causes the dry type of earwax and produces less underarm body order, compared with other ethnicities.
ABCC11: the “no body odor gene”
Genetic variants that cause a loss of function of the ABCC11 gene are very common among East Asian populations (80-90% of the population). In other population groups, it is rare to have no body odor.
The ABCC11 gene is located on human chromosome 16q12. 1 [6–8]. ABCC11, also known as multidrug resistance-associated protein 8 (MRP8), is a full ABC transporter with a total of 12 putative transmembrane domains and two ATP-binding cassettes [9].
A recent study6 showed that a single-nucleotide polymorphism, (SNP) 538 G → A (rs17822931), in the adenosine triphosphate (ATP)-binding cassette, sub-family C11 (ABCC11) gene is responsible for the earwax phenotypes: G for the dominant (wet) allele and A for the recessive (dry) allele.
Recently, genetic variants of ABCC4 (OMIM: 605250) and ABCC11 (OMIM: 607040), which are particularly common in the Japanese population, were suggested as possible genetic susceptibility factors for the development of SMON.
A Functional ABCC11 Allele Is Essential in the Biochemical Formation of Human Axillary Odor. The characteristic human axillary odor is formed by bacterial action on odor precursors that originate from apocrine sweat glands.
According to a group of researchers from the University of Bristol in the UK, 2 percent of people (at least in their survey) carry a rare version of the gene ABCC11 that prevents their armpits from producing an offensive odor.
Is there a test for body odor?
To diagnose a problem with sweating and body odor, your doctor will likely ask about your medical history and do an exam. The doctor may test your blood or urine. The tests can show if your problem is caused by a medical condition, such as an infection, diabetes or an overactive thyroid (hyperthyroidism).
Trimethylaminuria (TMAU) is an uncommon condition that causes an unpleasant, fishy smell. It's also called "fish odour syndrome". Sometimes it's caused by faulty genes that a person inherits from their parents, but this isn't always the case. There's currently no cure, but there are things that can help.
While only 2 percent of Europeans lack the genes for smelly armpits, most East Asians and almost all Koreans lack this gene, Day told LiveScience.
The frequencies of the A and G alleles vary markedly across different ethnic groups. The A allele is very common in East Asians, and as expected, most people in this population don't need to use deodorant. And so they don't use it—it's estimated that only 7% of North East Asians regularly use deodorant.
For instance, studies suggest that Asians and Native North Americans sweat less than Caucasians and people of African descent. But race is not the only determining factor for individual aromas. Just like fingerprints, BO is unique to every person, even for people who share living spaces and dietary habits.
Earwax comes in two types, wet and dry. The wet form predominates in Africa and Europe, where 97 percent or more of the people have it, and the dry form among East Asians, while populations of Southern and Central Asia are roughly half and half.
The genetic link
You can thank your ABCC11 gene for your earwax type. This gene contains instructions for a protein that moves fat into, and out of, your cells. People who have 1 or 2 copies of the C variant in the ABCC11 gene have more fat in their earwax, making it wet and sticky.
Also mentioned in the study: "Africans" have "wet, yellowish-brown wax," and Native Americans — similar to East Asian folks — typically have "dry, white wax." "The difference between [the earwax] is caused by a single gene in the genome.
Research suggests that yes, genetics can influence whether you're one of the many whose sweat contains compounds that bacteria eat, leading to armpit odor. However, genetics can also determine how you interpret smells, including body odor.
The ABCC11 gene is present in the human genome as two alleles, differing in one nucleotide also known as a single nucleotide polymorphism (SNP).
Why do East Asians not sweat?
Relevant paragraph from Wikipedia from the article on body odor below, but the TL;DR is that there's a gene called ABCC11 that is non-functional in 80 to 95 percent of East Asians. That allele determines both apocrine sweat gland size and activity, concentration of protein in apocrine sweat, and, oddly, wet-type vs.
ODOR AFTER A SHOWER IS DUE TO LINGERING BACTERIA
In addition to bacteria, oftentimes there is deodorant residue and other impurities that are trapped in the underarm pores and within the hair if you have armpit hair.
Oranges, lemons, and grapefruits are packed full of pleasant-smelling oils and compounds, which quickly become absorbed by the body and gently released through the skin. As such, eating such fruits is a quick way to improve your natural aroma.
When your body temperature rises, these glands release fluids that cool your body as they evaporate. Apocrine glands are found in areas where you have hair, such as your armpits and groin. These glands release a milky fluid when you're stressed. This fluid is odorless until it combines with bacteria on your skin.
No employment law specifically addresses body odor as a disability, but some courts have ruled that certain situations of body odor or perceived disability do, in fact, count as a disability under the ADA. The definition of disability according to the ADA is a wide one.
A recent study6 showed that a single-nucleotide polymorphism, (SNP) 538 G → A (rs17822931), in the adenosine triphosphate (ATP)-binding cassette, sub-family C11 (ABCC11) gene is responsible for the earwax phenotypes: G for the dominant (wet) allele and A for the recessive (dry) allele.
When your body temperature rises, these glands release fluids that cool your body as they evaporate. Apocrine glands are found in areas where you have hair, such as your armpits and groin. These glands release a milky fluid when you're stressed. This fluid is odorless until it combines with bacteria on your skin.
ABCC11. The ABCC11 gene determines axillary body odor and the type of earwax. The loss of a functional ABCC11 gene is caused by a 538G>A single-nucleotide polymorphism, resulting in a loss of body odor in people who are specifically homozygous for it.
According to the DAVID report, the group of genes annotated by the GO term sensory perception of smell includes 45 genes encoding odorant receptors and three other genes: OBP2A (Odorant-binding protein 2a); GNAL (guanine nucleotide binding protein (G protein), alpha activating activity polypeptide, olfactory type); and ...
Animals possess an inborn ability to recognize certain odors to avoid predators, seek food, and find mates. Innate odor preference is thought to be genetically hardwired.
What race has wet earwax?
Also mentioned in the study: "Africans" have "wet, yellowish-brown wax," and Native Americans — similar to East Asian folks — typically have "dry, white wax." "The difference between [the earwax] is caused by a single gene in the genome.
In fact, according to research published in Nature, your nose can detect about one trillion smells! But your own underarms could reek and you might not be able to tell: Humans are prone to what scientists call olfactory fatigue; our sense of smell just gets plain tired out by familiar odors and stops detecting them.