Alpha thalassemia major: counseling for the possibility of long-term survival

Abstract

Deletion of all four alpha globin genes most often leads to fetal demise or stillbirth secondary to hydrops fetalis. In recent years, long-term post-natal survival has been reported in a handful of cases, some following stem cell transplantation and/or intrauterine transfusion. Given the possibility of treatments that may enable long-term survival and ameliorate some associated sequelae, there are several issues to consider when counseling the couple with an affected fetus. We report a Laotian female long-term survivor with alpha thalassemia major, a case that illustrates several issues.

Our patient was born to a 23 year-old G2,P1-2 Khmu-speaking woman whose carrier status was not previously identified. Fetal ultrasound at 37 3/7 weeks revealed intrauterine growth retardation, hepatomegaly, abdominal ascites, and an enlarged umbilical vein. Ultrasound at 38 2/7 weeks additionally noted fetal cardiomegaly. The infant was delivered by emergency cesarean section at that time secondary to hydrops and fetal distress. Birth weight was 2200 grams, length was 43 cm, and head circumference was 31 cm (all < 3rd percentile). Immediate intubation and ventilator support were required, as well as a packed red cell transfusion and an exchange transfusion. DNA analysis revealed homozygosity for the Southeast Asian two alpha globin gene deletion (- -^SEA/- -^SFA). The child, now 2 years of age, has since been on chronic transfusion therapy to maintain a Hb H level of 20-35%. Formal testing has shown normal development and appropriate growth parameters. At age 8 months, an echocardiogram identified a 9-10 mm atrial septal defect, which awaits surgical repair. Bone marrow transplantation is an option for this child who has an HLA-matched sibling. The role of family members has been tremendously important to the process of informed medical decision-making and in the provision of appropriate care.

This case illustrates several important counseling issues. Appropriate carrier screening is necessary prior to conception or early in pregnancy. Once an affected fetus is identified, feasibility of in-utero treatment options should be reviewed along with a discussion of possible maternal risks and future clinical implications for the affected child. Postnatal transfusion requirements are similar to those for a child with beta thalassemia major. Iron overload and chelation therapy should be discussed, as well as the possibility of bone marrow transplantation given a matched donor. The increased risk for developmental delay and congenital malformations in alpha thalassemia major should also be considered. In all cases, parents should be involved in the decision-making process, and cultural and social considerations should be addressed.