A novel epsilon gamma delta beta thalassemia presenting with pregnancy complications and severe neonatal anemia

Abstract

The epsilon gamma delta beta (εγδβ)-thalassemias are rare sporadic disorders caused by deletion of the β-globin gene cluster. The main clinical feature is marked prenatal and neonatal anemia that resolves spontaneously within a few months. Reports originating mainly from Europe have so far identified 30 such deletions The aim of the present work was to describe a novel 1.78-Mb deletion, the longest ever reported, and to detail the clinical features in 12 members of an extended Bedouin family. The deletion was identified by globin gene multiplex ligation-dependent probe amplification (MLPA) of the β-globin cluster and further characterized by comparative genomic hybridization. Past and present clinical and laboratory data of ten symptomatic and two asymptomatic patients were collected. A 1.78-Mb εγδβ-deletion, the largest ever described, was identified in all patients. Although other genes were included in the deletion, no other symptoms were observed. Of the ten symptomatic fetuses and neonates, three died of the disease. The remainder required packed cell transfusions during the first months of life. Pregnancy complications included intrauterine growth restriction and oligohydramnios, as well as additional neonatal complications including prematurity and persistent pulmonary hypertension of the neonate. We suggest that εγδβ-thalassemia be added to the list of hemoglobinopathies that can cause neonatal anemia and that MLPA of the β-globin cluster be used to confirm its diagnosis. Careful surveillance during pregnancy is important to reduce neonatal mortality and morbidity, especially given the dramatic improvement that occurs later.