rs121909377
A SNP in the MYBPC3 gene on chromosome 11. Its most notable genotype is A;C: Miscall likely if from 23andMe data; If not, familial hypertrophic cardiomyopathy 4
- Gene
- MYBPC3
- Location
- Chr 1147,333,238 (GRCh38)
- Highest magnitude
- 4.0Very important
- Tested on
- Not on consumer chips
Genotypes
Plus strand, as in 23andMe and AncestryDNA files.
- C;CGoodcommon in clinvar
- A;CMost notableBadMiscall likely if from 23andMe data; If not, familial hypertrophic cardiomyopathy 4
SNPedia records rs121909377 on the minus strand: (G;G), (G;T). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.
Related
Conditions, medicines and genes
Other MYBPC3 SNPs
- rs397515963C;CLikely severe cardiomyopathyVery important
- rs200411226C;THypertrophic CardiomyopathyVery important
- rs375882485A;Gfamilial hypertrophic cardiomyopathy mutationVery important
- rs786204338C;GHypertrophic CardiomyopathyVery important
- rs1060501474G;THypertrophic CardiomyopathyVery important
- rs111683277C;TFamilial Hypertrophic CardiomyopathyVery important
- rs111729952C;TFamilial Hypertrophic CardiomyopathyVery important
- rs113358486A;CFamilial Hypertrophic CardiomyopathyVery important
Notes
From SNPedia
Notes
The rare minor allele of this variant is reported to be pathogenic/likely pathogenic for familial hypertrophic cardiomyopathy (HCM), according to .
A;C
1999 and 2015 publications report that the minor allele is a dominant mutation leading to familial hypertrophic cardiomyopathy 4. However, SNPedia has observed that 23andMe data may miscall this mutation, and their customers should check their i5005171 genotype, which independently checks this mutation. If i5005171 is CC, it's the common/normal genotype, but if i5005171 is AC, it confirms carrying the rare HCM mutation originally reported in 1999.
Source and license
Adapted from rs121909377 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.