Haemoglobin Bartβs hydrops fetalis syndrome (BHFS) represents the most severe form of Ξ±-thalassaemia, arising from deletion of the duplicated Ξ±-globin genes from both alleles. The absence of Ξ±-globin leads to the formation of non-functional haemoglobin Bartβs (Ξ³4) or haemoglobin H (HbH: Ξ²4) resulting in severe anaemia, tissue hypoxia, and, in some cases, variable congenital or neurocognitive abnormalities. BHFS is the most common cause of hydrops fetalis in Southeast Asia; however, owing β¦