Merge/Consolidate data in specific columns

[tjohnpok]

I have a list of patients with numbered tumor sites and I'm looking for a way to consolidate my data with entries for a third column (genotype) which remains not assigned (NA) until I receive the final results from all the hospitals within my region. The function might look like a double vertical lookup, but I'm looking for the best practice when it comes to merging that kind of data.

I'm posting the data here, because the attachment option does not show my uploaded file within the post.
===Sheet1===
Patient Tumor Genotype
PT01 1 NA
PT01 2 NA
PT02 1 NA
PT02 2 NA
PT02 3 NA
PT03 1 NA
PT04 1 NA
PT05 1 NA
PT06 1 NA
PT07 1 NA
PT07 2 NA
PT08 1 NA
PT09 1 NA
PT10 1 NA
PT10 2 NA
PT10 3 NA
PT10 4 NA
PT10 5 NA
PT10 6 NA

===Sheet2===
Patient Tumor Genotype
PT01 1 GG
PT01 2 TT
PT02 3 GG
PT03 1 TT