What EDAR rs3827760 Means in Your 23andMe Raw Data

rs3827760 is the EDAR marker behind what gets called thick, straight East Asian hair. In a 23andMe raw file it is reported as A/G. The G allele codes for the EDAR V370A change; A/A means no V370A copy at this marker, A/G means one, and G/G means two. That is a normal physical trait variant, not a diagnosis.

What does EDAR rs3827760 mean in my 23andMe raw data?

If you search rs3827760 in your 23andMe raw data, you will see a line with the marker, chromosome 2, position, and a two-letter genotype. On the build 23andMe uses, the position is around 109,513,601 and the call is AA, AG, or GG. The order in a file is not meaningful: AG and GA are the same call. -- or a missing line is a failed read, not a third result.

The G allele is the one carrying the V370A substitution. It swaps a valine for an alanine at position 370 of the EDAR protein. East Asian and Native American reference populations usually carry G at high frequency. European and African reference populations usually carry A at high frequency. If another site reports C/T for the same marker, it is likely using the opposite DNA strand; 23andMe's raw file uses A/G.

One G copy nudges the trait. Two G copies nudge it more. The variant influences a normal range, it does not switch hair or teeth into a fixed category.

Why a receptor changes hair, teeth and sweat

EDAR is the ectodysplasin A receptor. During development, it sits on cells that will form skin appendages: hair follicles, teeth, sweat glands. The V370A change makes the receptor signal more strongly. In hair follicles, stronger EDAR signalling leads to a wider hair shaft and a rounder, straighter follicle. In dental development, it pushes the back of the upper incisors to form a ridge called a shovel shape. In skin, it increases eccrine sweat gland formation. That is why a single marker shows up in three traits that look unrelated on the surface.

What this does not tell you

• It does not tell you your hair is straight. Many genes shape hair, and so do heat, dye, humidity, damage and age. Some G/G people have wavy or looser hair.
• It does not tell you your ancestry. G/G is common in East Asian and Native American populations but one marker is not an ancestry test.
• It does not diagnose anything. This is a common variant, not a disease allele.
• It does not tell you your teeth must be shovel-shaped. The variant raises the chance, but tooth shape is also influenced by other genes and dental wear.

The most common mistake is treating G/G as a guarantee of straight thick hair, or treating A/A as something broken. Both forms are normal versions of the EDAR protein with different developmental output.

Does G/G mean shovel-shaped incisors?

It raises the likelihood. Shovel-shaped incisors are a continuous trait, not present or absent. In people with two V370A copies, the ridge tends to be more pronounced. In A/G it is intermediate. In A/A the ridge is usually absent or faint. It is not a diagnostic sign. A look in the mirror says more than this single SNP.

The follow-up people miss: sweat glands

The same EDAR signal that changes hair and teeth also influences eccrine sweat gland density. Mouse models carrying V370A grow more eccrine glands. Human studies find the effect is subtler. G/G is associated with slightly denser sweat glands on average, but the range within any genotype is large. G/G does not mean you will sweat heavily, and A/A does not mean you cannot thermoregulate. It means the structure was built with a different default.

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The download steps for 23andMe, on the page itself.

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The short version: what is worth acting on, first.

If you have a 23andMe, AncestryDNA, MyHeritage or whole-genome VCF file, the free DNA report reads EDAR among the traits in your own file. It parses the file in the browser, shows the story before any email, and the full report is free after a one-time code. Good next step if you want to see rs3827760 in your own data instead of someone else's reference table.