Hemoglobin Bart's Disease and the Agrinio Mutation: A Case Report of Successful Fetal Intervention

Hemoglobin Bart's hydrops fetalis syndrome (BHFS) is the most severe form of α-thalassemia, typically caused by homozygous deletion of α-globin genes. However, rare non-deletional variants, such as Hemoglobin (Hb) Agrinio, can also produce a lethal phenotype.

We report a case of homozygous Hb Agrinio (HBA2:c.89T>C, p.Leu30Pro) diagnosed prenatally in a fetus of Bulgarian origin presenting with hydrops and severe anemia at 23 weeks of gestation. Following diagnosis, the pregnancy was managed with five intrauterine transfusions, resulting in resolution of hydrops and prolongation of pregnancy to term. The neonate was delivered at 37+3 weeks, required transient respiratory and cardiovascular support, and remains clinically stable at 3 months of age under regular transfusion therapy.

To our knowledge, this is only the second reported case of BHFS resulting from homozygous Hb Agrinio successfully managed with intrauterine transfusions, and uniquely, the first to achieve term delivery. This case highlights the importance of considering unstable α-globin variants in the differential diagnosis of unexplained fetal hydrops in an at-risk population. Early diagnosis and timely intrauterine transfusions can significantly improve the perinatal outcomes in these cases.