P18.07: Managing severe fetal anemia due to a new form of εγγδβ thalassemia in a Nordic family: intrauterine transfusions prior to final diagnosis

Abstract

This case highlights the need to consider diagnoses of rare conditions not normally associated with a particular population. A hydropic fetus presented at 29 + 1 weeks with extensive ascites, pericardial fluid, enlarged heart and hyperkinetic circulation. Maximum velocity in the middle cerebral artery was 76 cm/s. The etiology of the fetal anemia was unknown. Both parents were of Nordic origin. The family history revealed that the father was born with anemia, in need of neonatal transfusions. No conclusive explanation for his anemia was found. His physical and neurological development was normal, although the microcytic anemia persisted. The family history made us consider a hereditary anemia in the fetus. The first cordocentesis revealed a microcytic anemia with Hb 5.8 g/dl, Hct 0.19, MCV 91 fl. Six intrauterine transfusions, until 34 completed weeks, were performed. The female infant was delivered by Cesarean section at 36 weeks. Her initial Hb level (transfused) was 14.1 g/dl; at one month of age her Hb was 8.8 g/dl, MCV 78 fl. She was transfused at this stage and again at about 2 months; since then her Hb has been stable at about 9 g/dl. She is healthy and her physical and neurological development has been normal. In the father, a deletion of the 5′ end of the β globin gene cluster was characterised, the breakpoints sequenced and a new type of eγγδβ thalassemia identified. Analysis of the daughter’s DNA by MPLA and Southern blotting confirmed that she had inherited the deletion chromosome from her father. The clinical presentation of eγγδβ thalassemia may vary but neonatal transfusions are frequently required due to marked neonatal anemia. A thorough family history may provide the suspicion of the potential diagnosis. Intrauterine transfusions should always be considered while further investigation takes place. A correct diagnosis provides a probable prognosis and also allows early prenatal diagnosis and optimal surveillance in future pregnancies.