Genetic Mutations of Congenital Red Cell Membrane Defects in Hydrops Fetalis.

Introduction: Hereditary pyropoikilocytosis (HPP) is a rare genetic disorder causing severe fetal anemia, often leading to hydrops fetalis. This study evaluates intrauterine blood transfusion (IUT) efficacy and associated genetic mutations in Northeastern Thai patients.

Methods: Eight fetuses with hydrops fetalis were identified between 17 and 30+6 weeks' gestation, with initial hematocrit levels of 8.7-16.7%.

Results: IUTs were performed at 20-36 weeks, guided by fetal hematocrit, middle cerebral artery peak systolic velocity, and fetal hemodynamic status. Five cases progressed uneventfully following IUTs, although three resulted in premature delivery. Four cases reached term, with two infants born at normal weight and two at low birth weight. Among premature cases, three had birth weights below the 10th percentile for gestational age, and one had normal weight. Five patients remain transfusion dependent. Genetic analysis revealed homozygous spectrin Providence in 4 patients, homozygous spectrin Buffalo in 1, compound heterozygous spectrin Providence/Buffalo in 2, and spectrin Providence with SPTB c.6171_6182delinsACCCCAGCT (novel) in 1. Three cases developed severe complications, including severe birth asphyxia, persistent pulmonary hypertension, and multiple organ failure, leading to death.

Conclusions: This study identified SPTB gene mutations associated with HPP. Early detection of hydrops fetalis caused by severe anemia, along with confirmation of the underlying genetic mutation, is essential for timely and effective clinical intervention. Intrauterine transfusion remains a viable therapeutic option to sustain pregnancy and enhance fetal survival. Further research is needed to refine the management strategies for HPP-associated hydrops fetalis and to improve perinatal outcomes.