rs9561778

A SNP in the ABCC4 gene on chromosome 13. Its most notable genotype is G;T: ~2x increased risk of adverse drug reactions from cyclophosphamide treatments

Gene
ABCC4
Location
Chr 1395,061,461 (GRCh38)
Highest magnitude
1.5Minor
Tested on
23andMe, AncestryDNA, FamilyTreeDNA
Minor allele frequency
18%

Genotypes

As shown in 23andMe and AncestryDNA files.

  1. G;GGoodNormal risk of adverse drug reactions from cyclophosphamide treatmentsMinor · 1.069% of people
  2. G;TMost notableBad~2x increased risk of adverse drug reactions from cyclophosphamide treatmentsMinor · 1.529% of people
  3. T;TBad~2x increased risk of adverse drug reactions from cyclophosphamide treatmentsMinor · 1.53% 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 69% G;T 29% T;T 3%
  • European ancestry (Utah)G;G 66% G;T 31% T;T 3%
  • Han Chinese (Beijing)G;G 52% G;T 38% T;T 10%
  • Japanese (Tokyo)G;G 59% G;T 41% T;T 0%
  • Yoruba (Nigeria)G;G 75% G;T 24% T;T 1%
  • African ancestry (Southwest US)G;G 68% G;T 32% T;T 0%
  • Chinese (Denver)G;G 54% G;T 37% T;T 9%
  • Gujarati IndianG;G 70% G;T 25% T;T 5%
  • Luhya (Kenya)G;G 76% G;T 24% T;T 0%
  • Mexican ancestry (Los Angeles)G;G 85% G;T 14% T;T 2%
  • Maasai (Kenya)G;G 79% G;T 21% T;T <1%
  • TuscanG;G 71% G;T 28% T;T 1%

Conditions, medicines and genes

Other ABCC4 SNPs

All ABCC4 SNPs

Notes

From SNPedia

Notes

rs9561778 is a SNP in the ATP-binding cassette, sub-family C (CFTR/MRP), member 4 ABCC4 gene. A stepwise case-control study of ~400 breast cancer Japanese patients receiving cyclophosphamide-based combination chemotherapy, roughly divided equally between those having or not having serious adverse drug reactions (ADRs), concluded that carriers of rs9561778(T) allele had a ~2x higher risk of ADRs. The ADRs for these patients tended to be gastrointestinal toxicity and leukopenia/neutropenia.

Source and license

Adapted from rs9561778 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.