When I read data about genomic variants, I saw something like this "chr19:5237294" to indicate the location in a sequence. I am really confused that the “19” is the pair number or chromosome number.
- If it is the pair number, how can we determine which chromosome in that pair they are talking about?
- If it is the chromosome number, do we have some notation like “chr25, chr26,….”? Actually, I have never seen them.
- In both cases, a chromosome has 2 strands, how can we know the variant (for example, an SNP) happens on which strand?
Could you please help me to understand such things above?
Thank you so much