Alpha thalassemia major is a hemoglobinopathy caused by the inactivation or deletion of all 4 α-globin alleles. We describe a case of α-thalassemia major with atypical ultrasound and neuropathological findings. The mother had her first prenatal visit at 27 4/7 gestational weeks. Ultrasound revealed a hydropic fetus with multiple anomalies. However, the middle cerebral artery peak systolic velocity (MCA-PSV) suggested that the likelihood of fetal anemia was low. Given the poor prognosis of hydrops fetalis, the parents opted for termination of pregnancy. The neonate died shortly after birth. Autopsy revealed a markedly hydropic female infant with severe limb reduction defects and, in contrast to what was suggested by the prenatal MCA-PSV measurement, unequivocal signs of severe anemia. The brain showed diffuse white matter gliosis. Genetic testing subsequently identified HBA1 and HBA2 deletions, consistent with α-thalassemia major. This case highlights the potential pitfall of MCA-PSV, which is nowadays considered the gold standard for noninvasive detection of fetal anemia. In addition, this is 1 of 2 published case reports detailing neuropathological findings in a fetus or neonate with α-thalassemia major and the first to link α-thalassemia major with diffuse white matter gliosis.
Keywords: alpha thalassemia major; diffuse white matter gliosis; hemoglobin Barts; homozygous alpha thalassemia; hydrops fetalis; neuropathology.