The Haemoglobin Constitution of Infants with the Haemoglobin Bart's Hydrops Foetalis Syndrome

Abstract

S ummary . The haemoglobin constitution of 14 infants with the haemoglobin Bart's hydrops syndrome has been examined. Thirteen of the infants were stillborn or lived only a few minutes after delivery, but in one case an exchange transfusion was performed and the pattern of globin chain synthesis examined by an [H 3 ]leucine incorporation experiment utilizing umbilical cord blood. These studies indicate that the syndrome results from a total deficiency of α‐chain production. Furthermore, it has been possible to exclude the presence of fragments of α‐chain longer than II residues in the cells of these infants. In each infant a small quantity of haemoglobin was found which consisted of normal γ‐chains in association with chains of unique constitution. A similar component was found in trace amounts in normal umbilical cord blood. This haemoglobin may be identical with haemoglobin Portland. It is suggested that the non‐γ‐chain of this haemoglobin is the product of a normal foetal haemoglobin locus which produces very small amounts of gene product in normal infants but which is capable of increased activity in the presence of a partial or total deficiency of α‐chains.