Report of the First International Workshop on molecular blood group genotyping.

The use of molecular genetic technology for blood group typing is becoming routine procedure in many reference laboratories worldwide. A First International Workshop was organized on behalf of the International Society of Blood Transfusion (ISBT) and the International Council for Standardization in Haematology (ICSH). Thirty laboratories that provide a molecular diagnostic service participated in the workshop. Six samples were distributed: two represented DNA from transfusion-dependent patients for testing for multiple polymorphisms; two represented fetal DNA prepared from amniotic fluid for RhD, Rhc and K-testing; and two represented plasma from RhD-negative pregnant women for fetal RhD testing. Error rates varied from 0 to 11% for different polymorphisms. A consensus arising from discussion on the workshop results between participants at a feedback meeting and by e-mail has resulted in seven recommendations for molecular blood group genotyping. Further international workshops will take place every 2 years, with a more limited exercise being organized in the intervening years.