germlines: TRDD2*01 and TRDD3*01 are not retrieved from IMGT
For DD2/DD3 recombinations we need respectively upstream and downstream sequences of the two genes. They are not included in IMGT, therefore we retrieve them from NCBI
For DD2/DD3 recombinations we need respectively upstream and downstream sequences of the two genes. They are not included in IMGT, therefore we retrieve them from NCBI