An adult autochthonous Dutch patient who had exhibited severe perinatal anaemia, with partial recovery a few months after birth, was studied for the presence of beta-thalassaemia. Southern blotting showed that the patient was heterozygous for a novel deletion in the beta-globin gene cluster, leaving the beta-gene intact. Inverse polymerase chain reaction was used to determine the breakpoint sequence. The deletion removed 112 kb starting upstream of the HOR5'b6 gene to the second intron of the Agamma-globin gene, including the locus control region. The breakpoint fragment identified a 13-bp orphan sequence not present at either side of the breakpoint.