Identification of the uncommon allele HLA-A*7403 in a Caucasian renal transplant cadaver donor: extension of the exon 4 sequence.

This report describes the unknown exon 4 sequence of the rare A*7403 allele, identified in a Caucasian renal transplant cadaveric donor from Italy. This sequence is identical to that of the only known A*7401 exon 4, and this result allowed us to confirm the hypothesis of the generation of A*7403 allele from the ancestor A*7402 by point mutation in exon 2.