rs12785878

A SNP in the NADSYN1 gene on chromosome 11. Its most notable genotype is T;T: slightly increased (1.4x) risk for vitamin D insufficiency

Gene
NADSYN1
Location
Chr 1171,456,403 (GRCh38)
Highest magnitude
1.8Minor
Tested on
23andMe, AncestryDNA
Minor allele frequency
47%

Genotypes

As shown in 23andMe and AncestryDNA files.

  1. G;GGoodCommon/normalTypical · 0.046% of people
  2. G;TBadslightly increased (1.2x) risk for vitamin D insufficiencyMinor · 1.538% of people
  3. T;TMost notableBadslightly increased (1.4x) risk for vitamin D insufficiencyMinor · 1.817% of people

On SNPedia: (G;G), (G;T), (T;T). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.

Frequency

Share of each genotype in 11 HapMap populations.

  • AverageG;G 46% G;T 38% T;T 17%
  • European ancestry (Utah)G;G 9% G;T 37% T;T 54%
  • Han Chinese (Beijing)G;G 22% G;T 56% T;T 22%
  • Japanese (Tokyo)G;G 45% G;T 48% T;T 7%
  • Yoruba (Nigeria)G;G 70% G;T 29% T;T 1%
  • African ancestry (Southwest US)G;G 44% G;T 49% T;T 7%
  • Chinese (Denver)G;G 28% G;T 61% T;T 11%
  • Gujarati IndianG;G 68% G;T 30% T;T 2%
  • Luhya (Kenya)G;G 88% G;T 12% T;T 0%
  • Mexican ancestry (Los Angeles)G;G 38% G;T 47% T;T 16%
  • Maasai (Kenya)G;G 85% G;T 14% T;T 1%
  • TuscanG;G 6% G;T 33% T;T 61%

Conditions, medicines and genes

Notes

From SNPedia

Notes

rs12785878, located near the 7-dehydrocholesterol reductase DHCR7 gene on chromosome 11q12, has been linked by several studies to vitamin D serum concentrations. In both studies, the allele associated with lower vitamin D, and thus the potential for vitamin D insufficiency, is rs12785878(G). Carriers of two such alleles have lower vitamin D than carriers of one allele, who in turn on average have lower vitamin D levels than rs12785878(T;T) individuals. A near-perfect proxy (i.e. substitute) for rs12785878 appears to be rs7944926.

G;T

see rs12785878

T;T

see rs12785878

Source and license

Adapted from rs12785878 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.