rs1056836
A SNP in the CYP1B1 gene on chromosome 2. Its most notable genotype is C;C: 0.3x decreased risk for prostate cancer
- Gene
- CYP1B1
- Location
- Chr 238,071,060 (GRCh38)
- Highest magnitude
- 2.0Worth knowing
- Tested on
- 23andMe, AncestryDNA, FamilyTreeDNA
- Minor allele frequency
- 39%
Genotypes
Plus strand, as in 23andMe and AncestryDNA files.
SNPedia records rs1056836 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.
Frequency
Share of each genotype in 11 HapMap populations.
- AverageG;G 39% C;G 34% C;C 27%
- European ancestry (Utah)G;G 34% C;G 43% C;C 23%
- Han Chinese (Beijing)G;G 81% C;G 19% C;C 0%
- Japanese (Tokyo)G;G 80% C;G 19% C;C <1%
- Yoruba (Nigeria)G;G 1% C;G 20% C;C 78%
- African ancestry (Southwest US)G;G 11% C;G 29% C;C 61%
- Chinese (Denver)G;G 68% C;G 31% C;C <1%
- Gujarati IndianG;G 66% C;G 30% C;C 4%
- Luhya (Kenya)G;G 4% C;G 37% C;C 59%
- Mexican ancestry (Los Angeles)G;G 43% C;G 52% C;C 5%
- Maasai (Kenya)G;G 10% C;G 46% C;C 45%
- TuscanG;G 31% C;G 53% C;C 16%
Related
Conditions, medicines and genes
Other CYP1B1 SNPs
- rs28936700C;TCarrier of a primary congenital glaucoma mutationImportant
- rs28936701A;GCarrier of a primary congenital glaucoma mutationImportant
- rs9282671T;Tsmall chance of slightly increasing risk for a form of glaucomaMinor
- rs1056827C;Ccommon in clinvarTypical
- rs1056837A;Acommon in clinvarTypical
- rs1800440T;Tcommon on affy axiom dataTypical
Notes
From SNPedia
Show notes, about 170 words
rs1056836, also known as 4326C/G, Val432Leu or L432V, is a SNP in the cytochrome P450 1B1 (CYP1B1) gene. This gene is a member of the CYP1 gene family and one of the major enzymes involved in the hydroxylation of estrogens, a reaction likely to be relevant in hormonal carcinogenesis. [In dbSNP orientation, the (C) allele encodes the Leu; the (G) the Val.] In a study of 153 Hispanic Caucasians with prostate cancer the rs1056836(G;G) genotype showed decreased risk compared to the more common (C;C) genotype (odds ratio = 0.31, p = 0.04, CI: 0.10-0.96). This report cites another study as indicating that rs1056836(C;C) high-risk stage III and IV breast cancer patients receiving dose-intense paclitaxel in combination with doxorubicin and cyclophosphamide experience a longer progression-free survival compared with patients with (C;G) or (G;G) genotypes. rs1056836 increases susceptibility to lung cancer among those who never smoked 2.7x times for (C:G) heterozygotes and 3.1x times for (G;G) homozygotes, based on a study of 160 US patients.
Source and license
Adapted from rs1056836 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.