Three new DRB alleles routinely identified by sequence-based typing: DRB1*010103, DRB1*0326 and DRB3*0219

Area of Science:

• Immunogenetics
• Molecular Biology
• Transplantation Science

Background:

• Accurate Human Leukocyte Antigen (HLA) typing is crucial for successful organ and bone marrow transplantation.
• The HLA-DRB locus is highly polymorphic and plays a significant role in immune response and transplantation compatibility.
• Continuous discovery of novel HLA alleles is essential for refining typing strategies and improving transplant outcomes.

Purpose of the Study:

• To report the identification and characterization of two new HLA-DRB1 alleles and one new HLA-DRB3 allele.
• To detail the specific mutations responsible for these novel alleles.
• To contribute to the growing database of HLA genetic diversity.

Main Methods:

• HLA-DRB generic and allele typing using commercial kits.
• Sequencing of exon 2 of the identified HLA-DRB genes.
• Analysis of point mutations and their impact on amino acid sequences.

Main Results:

• Identification of a novel HLA-DRB1*010101 allele with a silent mutation at codon 68.
• Discovery of a novel HLA-DRB1*0306 allele with a T-C mutation at codon 38, resulting in a Val to Ala amino acid substitution.
• Characterization of a new HLA-DRB3*0219 allele differing from DRB3*020201 by mutations at codons 60 and 74, causing Tyr to Ser and Gln to Arg substitutions.

Conclusions:

• The identified novel HLA alleles expand the known HLA genetic diversity.
• These findings underscore the importance of ongoing HLA allele discovery for transplantation.
• Detailed molecular characterization provides valuable data for immunogenetic databases and future research.