[H-deficient variants in the Bulgarian population]

Area of Science:

• Immunogenetics
• Hematology
• Population Genetics

Background:

• The ABO blood group system is crucial in transfusion medicine and human genetics.
• Understanding variations in H antigen expression is key to characterizing complex blood group phenotypes.
• Previous studies have identified several H antigen phenotypes, but a comprehensive classification is ongoing.

Purpose of the Study:

• To systematically identify and classify novel H antigen phenotypes in a large population.
• To investigate the immunogenetic basis of these H antigen variants.
• To propose a genetic model explaining the observed H antigen phenotypes.

Main Methods:

• Phenotypic determination based on immunogenetic analysis, including quantitative A, B, H antigen studies.
• Serological investigation of anti-H, anti-A, and anti-B allohemagglutinins.
• Analysis of salivary secretor status.

Main Results:

• Identification of eight novel AHm phenotypes, one AHmB phenotype, and three OHm phenotypes.
• Phenotype determination was solely based on immunogenetic and serological data.
• A significant proportion of the studied population exhibited these newly defined H antigen variations.

Conclusions:

• The study successfully characterized several new H antigen phenotypes.
• A genetic model involving non-allelic suppressor genes is proposed to explain the control of H antigen phenotypes.
• These findings contribute to a deeper understanding of blood group diversity and immunogenetics.