How Do I Find My Genotype for a Specific rsID in My Raw DNA File

Open your raw DNA file in the free rsID lookup at https://healthosx.com/dna/lookup, paste the rs number or numbers, and you get your genotype and the position for each. It reads 23andMe, AncestryDNA, MyHeritage, FamilyTreeDNA, Living DNA, WeGene and annotated VCF files entirely in your browser. The file is never uploaded, and there is no account.

How do I find my genotype for a specific rsID in my raw DNA file?

Start with the raw data download, not the PDF report and not the web dashboard. The file you want is a .txt, .csv, .zip, .vcf or .vcf.gz. Some companies zip it inside a download. You can leave a .zip as it is.

1. 1.Choose the file on https://healthosx.com/dna/lookup.
2. 2.Paste up to 100 rs numbers, separated by spaces, commas or new lines.
3. 3.Press Look up.

For each rsID the page returns the two letters in your file and the chromosome and position. A chip file line has an rsID, chromosome, position, and the two letters. The lookup matches the rsID column, not the position column, and returns the letters and position from the matched line. You are not converting the file.

If you would rather do it by hand, open the text file in a plain text editor, not Excel. Search for the rsID exactly as it appears, such as rs4988235. A chip file has comment lines starting with # and then one marker per line. A VCF has ## lines and a header starting with #CHROM.

What does the lookup actually return?

Genotype and position only. No-calls stay no-calls. A raw VCF may record the same state as ./. or .. One letter is normal on the Y chromosome in a male, because there is no second chromosome to call. For your file's no-call rate, use the file checker at https://healthosx.com/dna/file-checker.

Positions are in the file's own coordinates. Most chip files are GRCh37, and a VCF may be GRCh37 or GRCh38. The lookup reports the position from the file and does not convert builds. If two tools disagree about a position, check which build each is using.

If HealthOS has published a guide for that SNP, the result links to it. Otherwise there is no added interpretation. Most single SNPs have no reliable meaning on their own, and inventing one on request would be the confident nonsense raw-data tools are known for. This tool does not do that.

Why does it say “not in your file”?

Different files contain different positions. A recent 23andMe v5 file lists roughly 630,000 markers. That is a lot, but there are tens of millions of known rsIDs. Most rsIDs are not on any one chip. When a chip file lacks an rsID, that means the chip did not test that position. It does not mean you lack the variant.

An annotated VCF usually works the opposite way. It lists where you differ from the reference, not every position. So when an rsID is missing from a VCF, the reasonable default is that you carry the reference allele.

A missing rsID on a chip means untested. A missing rsID in a VCF usually means reference.

A no-call is not the same as a missing rsID. It means the chip or caller tried to read the position but could not. Do not infer a genotype from a no-call.

What if my file is a VCF with no rsIDs?

An unannotated VCF cannot be looked up by rsID, because the ID column is empty and there is nothing to match. Annotate it against dbSNP first, then the same lookup works. If you only have a VCF without rsIDs, the lookup page cannot guess which rsID belongs to which position. A separate converter can write a chip-style file from the same positions, but that is a conversion, not a lookup.

Which strand are the letters on?

The strand your file uses. 23andMe and AncestryDNA report the forward (+) strand of the reference genome. Some papers and websites report the opposite strand. A pairs with T, and C pairs with G. So a paper may say A while your file says T, and both can describe the same base pair. The lookup does not flip alleles. It shows what the file contains.

What does my genotype mean?

Get the letters first, then ask what they mean. The lookup links out only where a HealthOS guide exists for that SNP. For a wider pass over your raw file, the full free report at https://healthosx.com/dna reads the same file and interprets the positions it has checked. It is still information, not a diagnosis.

Open the HealthOS rsID lookup at https://healthosx.com/dna/lookup and see your own letters. It takes less than a minute.