rs28936679
A SNP in the AANAT gene on chromosome 17. Its most notable genotype is A;G: in Japanese, possible delayed sleep phase condition
- Gene
- AANAT
- Location
- Chr 1776,469,731 (GRCh38)
- Highest magnitude
- 2.0Worth knowing
- Tested on
- 23andMe
- Minor allele frequency
- <1%
Genotypes
As shown in 23andMe and AncestryDNA files.
- A;GMost notableBadin Japanese, possible delayed sleep phase condition
- G;GGoodcommon in complete genomics
On SNPedia: (A;G), (G;G). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.
Related
Conditions, medicines and genes
Notes
From SNPedia
Show notes, about 140 words
rs28936679, also known as Ala129Thr or A129T (and also G619A), is a SNP in the aralkylamine N-acetyltransferase AANAT gene. The AANAT protein plays a unique role in vertebrate biology by controlling rhythmic production of melatonin in the pineal gland. Its activity increases 10- to 100-fold at night, leading to increased production and release of melatonin. In a 2003 report about Japanese patients with a sleep disorder known as susceptibility to delayed sleep phase syndrome, patient genotypes had a higher frequency of the rs28936679(A) allele. A later report based on Brazilian (primarily Caucasian) patients including those with delayed sleep phase syndrome found no variation at this SNP.
A;G
This genotype has been reported to be associated with delayed sleep phase syndrome in a Japanese group of patients.
Source and license
Adapted from rs28936679 on SNPedia, using a snapshot taken October 16, 2026. SNPedia content is shared under CC BY-NC-SA 3.0 US, and this page is shared under the same license.
SNPedia is a community-edited wiki. Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice. Magnitude is a community rating of how interesting a genotype is, not a risk score.