Assessed by IARC on December 2, 2019 during meeting 46.

The committee considered IGHV4-4*08_S8301 (T165C,C237A) of Genotype B16 of submission S00010, which was previously evaluated as IGHV4-4*08_S4567 as part of submission S00006 at Meeting 12. It was affirmed as a Level 0 sequence at that time, because of haplotype analysis that at the time was considered inconclusive.

The sequence was seen in 1.81% of all unmutated rearrangements, with 12648 sequences including 5107 perfect matches to the inferred allele. There was abundant variation in the CDR3 regions of the aligned sequences. One other IGHV4-4 allele was present in the genotype, as well as two likely IGHV4-59 sequences and one IGHV4-61 sequence. Haplotype data is supportive of the inference, though the haplotype ratios likely reflect the presence of some artefacts within the dataset. The ratios for the two IGHV4-4 sequences were 75:25 and 81:19, suggesting that both sequences are carried on the IGHJ6*02-bearing chromosome. The sequence, up to and including nucleotide 318, was affirmed as a Level 1 sequence. Uncertainty regarding nucleotides 319 and 320 is indicated in IARC and OGRDB publications by two dots at the end of the affirmed sequence. The committee believes it is most likely that the 319th nucleotide is ‘C’.