Abstract
On a field trip to Saudi Arabia in which the relationship between .alpha.-thalassemia and Fe deficiency was studied, a fast moving Hb variant was noted in a 30 yr old Saudi Arabian woman. Analysis of the Hb variant showed that the amino acid substitution was .beta.120 Lys .fwdarw. Asn. This variant had not been described previously. It was named Hb Riyadh. There was also present an .alpha.-thalassemia and details are given of the imbalance of globin chain synthesis. It was possible to improve considerably the balance in vitro by the addition of hemin.