Diagnostic challenges posed by a rare alpha globin chain variant Hb Fontainebleau in a pregnant female and its potential effects in her children in view of multiple globin gene defects in her husband

Abstract

Alpha globin chain variants per se do not cause severe morbidity and mortality but can modify – usually ameliorate – the clinical manifestations of beta globin chain variants when co-inherited with the latter. They also pose challenges in interpretation of high-performance liquid chromatography histograms and require molecular analysis for proper characterization. Hemoglobin (Hb) Fontainebleau is a rare alpha globin chain variant [alpha 21(B2) Ala→Pro], of which only three families have been reported from India in the past. Here, we describe a case of Hb fontainebleau detected in heterozygous condition in a 19-year-old primigravida. Her husband was found to have a double heterozygous state for HbQ India and beta-thalassemia trait. This opens up the possibility of multiple combinations of hemoglobinopathies in the offspring.

Keywords

• Alpha globin gene variants
• antenatal screening
• co-inheritance of alpha and beta globin chain variants
• HbQ India
• Hemoglobin Fontainebleau