In this letter Professor Bola Owolabi, Professor Dame Sue Hill, Duncan Burton, Dr Gail Miflin and Professor David Roberts ask hospital trusts and integrated care boards to encourage and promote patient referrals to the Blood Group Genotyping project at every opportunity.

This will help ensure that all patients with sickle cell and thalassemia and transfusion-dependent rare anaemias attending hospital are invited to have a blood group genotype DNA-based test alongside their routine blood test, even if they have had an extended red cell genotype or phenotype before.