Assessed by IARC on November 18, 2019 during meeting 45 and on December 2, 2019 during meeting 46.

The committee considered IGHV4-61*01_S5549 (C136G A138G) of Genotype B16 of submission S00010, which was previously evaluated as IGHV4-61*01_S0787 of submission S00006 at Meeting 12. It was affirmed as a Level 0 sequence at that time.

The sequence was seen in 1.68% of all unmutated rearrangements, with 11,785 sequences including 4732 perfect matches to the inferred allele. There was abundant variation in the CDR3 regions of the aligned sequences. No other allele of IGHV4-61 was present in the genotype. Haplotype data is supportive of the inference, with the sequence being strongly associated with one haplotype. However, two alleles of IGHV4-4 (a gene closely related to IGHV4-61) were present on the other haplotype, highlighting the possibility that one of these alleles might be an allele of IGHV4-61. There was strong support for the sequence being affirmed up to and including nucleotide 319, in line with IARC policy, as a Level 1 sequence, with one additional 3’ nucleotide being likely present in the sequence. This is indicated in IARC and OGRDB publications by one dot at the end of the sequence.