Ana M. Lazaro

Four Locus High Resolution HLA typing in a Sample of Mexican Americans

Mexicans are the most common minority population of the United States. From a sample of 553 bone marrow donor registrants of self-described Mexican ancestry, human leukocyte antigen (HLA) loci A, C, B and DRB1 were typed by high resolution sequence based typing (SBT) methods. A total of 47, 34, 76 and 46 distinct alleles at A, C, B and DRB1 respectively were identified, including 3 new alleles. The four-locus haplotype frequency distribution was extremely skewed with only 53.9% of 1106 chromosomes present with more than one estimated copy. Haplotypes of Native American origin were identified. These data form an initial basis for determining the requirements for an adequate donor pool for stem cell transplantation in this population.

Twenty-three novel alleles increase diversity at the HLA-C locus.

Twenty-three novel HLA-C alleles are described. Nine of the new alleles are single-nucleotide substitutions from their most homologous allele of which seven result in amino acid changes (Cw*0327, *0508, *0514, *0613, *0735, *0739 and *1517) and two are silent substitutions (Cw*030305 and *070107). The remaining 14 alleles (Cw*0113, *0207, *0212, *0216, *0318, *0411, *0417, *0512, *0722, *0733N, *1216, *1218, *1515 and *1607) differ from their most similar alleles by 2-4 nucleotide substitutions that result in 1-3 amino acid differences.

Expanding diversity at the HLA-B locus: 28 novel HLA-B alleles.

Twenty-eight novel human leukocyte antigen-B alleles are described: one B*07 (*0745), two B*08 (*0826 and *0831), one B*27 (*2731), four B*35 (*350106, *350402, *3566, and *3568), two B*37 (*370102 and *3711), two B*38 (*380102 and *3813), two B*39 (*3935 and *3939), one B*41 (*4108), one B*42 (*4209), two B*44 (*4444 and *4448), two B*48 (*480302 and *4815), one B*51 (*5140), one B*55 (*5523), one B*56 (*5617), two B*57 (*570103 and *5710), and three B*15 (*9505, *9510, and *9519). Sixteen of the variants are single-nucleotide substitutions from their most homologous allele, of which 10 result in amino acid changes (B*0745, *0831, *3813, *3935, *3939, *4815, *9505, *9509, *9510, and *9519) and 6 are silent substitutions. The remaining alleles (B*0826, *2731, *3566, *3568, *3711, *4108, *4209, *4444, *4448, *5140, *5523, *5617, and *5710) differ from their most similar alleles by two to seven nucleotides substitutions, altering from one to five amino acids.

Identification of a novel HLA-A*02 variant, HLA-A*02:586, in a Taiwanese bone marrow hematopoietic stem cell donor.

One nucleotide substitution at residue 179 of the HLA‐A*02:07:01 results in a new allele, HLA‐A*02:586.

HLA-A*02:06:21, a novel variant of HLA-A*02:06, discovered in a Taiwanese bone marrow hematopoietic stem cell donor.

One nucleotide substitution at residue 318 of the HLA‐A*02:06:01:01 results in a new allele, HLA‐A*02:06:21.One nucleotide substitution at residue 318 of the HLA-A*02:06:01:01 results in a new allele, HLA-A*02:06:21.

Detection of a novel HLA-A*11 variant, A*11:255, in a Taiwanese individual

One nucleotide substitution at residue 532 of HLA‐A*11:02:01 results in a novel allele, HLA‐A*11:255.