A sequence with homology to human HPFH-linked enhancer elements and to a family of G-protein linked membrane receptor genes is located downstream of the chicken beta-globin locus.

We report 5805bp of novel sequence (GenBank/EMBL Accession No. AJ012570) from a region starting approx. 11.5kb downstream of the chicken beta-globin locus (map position approx. +30.8 to +36.6kb), which contains a 945bp open reading frame (map position approx. +33 to +33.9kb). This is predicted to encode a 315-residue protein containing seven hydrophobic helical regions and a 17 amino acid motif characteristic of the R7G family of G-protein coupled membrane-bound receptors. The open reading frame and some surrounding sequence also have significant homology with the breakpoint enhancer elements, which also contain open reading frames, implicated in the HPFH-1/2 and HPFH-6 deletional forms of the human syndrome, hereditary persistence of foetal haemoglobin (HPFH). The existence of similar sequences at similar distances downstream of the beta-globin genes in chickens and HPFH patients is intriguing.