Rs121908789

rs121908789 is reported as a pathogenic SNP for cystic fibrosis in several sources, however, there is ambiguity in how it is reported so be sure to double-check any results regarding this SNP. This SNP is also known as c.3773dupT, p.Leu1258PhefsTer7, and perhaps most commonly, 3905insT.

In genome build GRCh37, the position for this SNP on chromosome 7 is 117282547:117282548 (where the additional insertion of a T takes place).

23andMe uses it's own code names for this SNP, namely i4000324 and i5012017. For these two SNPs, the common/normal allele is 'D', and therefore the common/normal genotype is DD.