rs113993962
A SNP in the BLM gene on chromosome 15. Its most notable genotype is -;-: Bloom syndrome; homozygote for most common mutation
- Gene
- BLM
- Location
- Chr 1590,766,923 (GRCh38)
- Highest magnitude
- 6.6Very important
- Tested on
- Not on consumer chips
Genotypes
As shown in 23andMe and AncestryDNA files.
- -;-Most notableBadBloom syndrome; homozygote for most common mutation
- -;ATCTGABadcarrier for Bloom syndrome mutation
- ATCTGA;ATCTGAGoodcommon in clinvar
On SNPedia: (-;-), (-;ATCTGA), (ATCTGA;ATCTGA). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.
Related
Conditions, medicines and genes
Notes
From SNPedia
Show notes, about 120 words
rs113993962 is a variant in the RECQL3 gene causing Bloom syndrome, and this particular SNP accounts for >95% of such cases in the Ashkenazi population. Note that this variation is somewhat complex, in that it represents a deletion of 6 bases along with an insertion of 7 bases at the same site. The terminology used in dbSNP (and here in SNPedia) indicates the normal allele as having the six bases ATCTGA, whereas the abnormal allele is shown only as a deletion of these six bases, without indicating the insertion. See also OMIM 604610.0001. 23andMe name: i4000396 However, note that the (D;D) genotype represents the normal genotype as reported for this i-SNP (contrary to convention)
-;ATCTGA
Unaffected in absence of a second mutation in the BLM gene
Source and license
Adapted from rs113993962 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.