rs1800972

A SNP in the DEFB1 gene on chromosome 8. Its most notable genotype is C;C: reduced risk for Crohn's disease; reduced risk for maternal HIV transmission

Gene
DEFB1
Location
Chr 86,877,901 (GRCh38)
Highest magnitude
2.0Worth knowing
Tested on
23andMe, AncestryDNA, FamilyTreeDNA
Minor allele frequency
15%

Genotypes

Plus strand, as in 23andMe and AncestryDNA files.

  1. G;GBadnormal riskTypical · 0.5
  2. C;GBadnormal riskTypical · 0.2
  3. C;CMost notableGoodreduced risk for Crohn's disease; reduced risk for maternal HIV transmissionWorth knowing · 2.0

SNPedia records rs1800972 on the minus strand: (C;C), (C;G), (G;G). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.

Conditions, medicines and genes

Other DEFB1 SNPs

All DEFB1 SNPs

Notes

From SNPedia

Show notes, about 150 words

rs1800972(G;G) homozygotes appeared be at less risk (by a factor of 3.3, p=0.01) for Crohn's disease, based on a study of 190 Caucasians. Based on a study of ~300 HIV-infected mothers, to whom were born ~100 HIV-infected children and ~200 uninfected, rs1800972 was associated with a modified risk for HIV transmission from mother to child. In children, the rs1800972(G;G) genotype and the rs1800972(G)/rs1799946(G) haplotype had a protective role against HIV-1 infection [odds ratio 0.52, CI: 0.31 - 0.86, p = 0.03 and OR = 0.50, CI: 0.31 - 0.83, p = 0.014, respectively]. In mothers, the rs1800972(G;G) genotype and the rs1800972(G)/rs1799946(G) were associated with low levels of HIV-1 plasma viremia (<1000 copies/mL) and a lower risk of maternal HIV-1 transmission (odds ratio 0.14, CI: 0.03 - 0.67, p = 0.009 and OR = 0.23, CI: 0.08 - 0.66, p = 0.012, respectively). C-44G rs1800972(G;G) Protective Crohn's disease

Source and license

Adapted from rs1800972 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.