rs4464148

A SNP in the SMAD7 gene on chromosome 18. Its most notable genotype is C;C: 1.35x increased risk for colorectal cancer

Gene
SMAD7
Location
Chr 1848,932,662 (GRCh38)
Highest magnitude
2.0Worth knowing
Tested on
23andMe, AncestryDNA, FamilyTreeDNA
Minor allele frequency
21%

Genotypes

As shown in 23andMe and AncestryDNA files.

  1. C;CMost notableBad1.35x increased risk for colorectal cancerWorth knowing · 2.05% of people
  2. C;TBad1.10x increased risk for colorectal cancerMinor · 1.523% of people
  3. T;TGoodNormal risk for colorectal cancerMinor · 1.072% of people

On SNPedia: (C;C), (C;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.

  • AverageC;C 5% C;T 23% T;T 72%
  • European ancestry (Utah)C;C 10% C;T 38% T;T 53%
  • Han Chinese (Beijing)C;C 0% C;T 5% T;T 95%
  • Japanese (Tokyo)C;C 0% C;T 7% T;T 93%
  • Yoruba (Nigeria)C;C 5% C;T 25% T;T 70%
  • African ancestry (Southwest US)C;C 2% C;T 32% T;T 67%
  • Chinese (Denver)C;C <1% C;T 9% T;T 90%
  • Gujarati IndianC;C 0% C;T 14% T;T 86%
  • Luhya (Kenya)C;C 6% C;T 26% T;T 69%
  • Mexican ancestry (Los Angeles)C;C 5% C;T 29% T;T 66%
  • Maasai (Kenya)C;C 1% C;T 33% T;T 66%
  • TuscanC;C 21% C;T 41% T;T 38%

Conditions, medicines and genes

Other SMAD7 SNPs

All SMAD7 SNPs

Notes

From SNPedia

Notes

rs4464148 is one of 3 SNPs in the SMAD7 gene associated with risk for colorectal cancer, based on a large study (7,400+ cases) conducted in the UK. The odds ratios show an increased risk for the minor rs4464148(C) allele; the OR for (C;C) homozygotes is 1.35 (CI: 1.2-1.51), and for (C;T) heterozygotes 1.10 (CI: 1.09-1.21), overall p=7x10 -8 .

Source and license

Adapted from rs4464148 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.