Molecular typing of blood group genes in diagnostics

: The molecular basis associated with the expression of all blood group antigens in the 43 blood group systems recognized by the International Society of Blood Transfusion (ISBT) was established and most are due to single nucleotide variations (SNVs). This allowed the development of a plethora of DNA tests to predict blood group antigens. Molecular typing of blood group genes in diagnostics facilitates the resolution of clinical problems that cannot be addressed by hemagglutination. They are useful to determine antigen types for which there is no typing reagents; to type patients who have been recently transfused or with warm auto antibodies; for definition of blood group variants; in prenatal testing; to search for rare blood types and to increase the reliability of repositories of antigen negative red blood cells (RBCs) for transfusion. This review summarizes the employment of molecular blood group typing and its benefits in diagnostics, especially in transfusion medicine and in maternal-fetal medicine. Advances in molecular methods have enabled the implementation of blood group genotyping in clinical laboratories changing work practices and revolutionizing the way transfusion is managed. The strength of next generation sequencing (NGS) of whole genomes or exomes or by targeting the specific blood group loci combined with pretransfusion serologic testing will enhance immunohematology in daily transfusion practice.