A New Gγ-Globin Variant Causing Low Oxygen Affinity: Hb F-Brugine/Feldkirch [Gγ105(G7)Leu→His; HBG2: c.317T>A]

AbstractIn two unrelated families, several newborns developed cyanosis within the first days of life. For all of them, consecutive arterial blood gas analyses showed a right shift of the saturation curve, suggesting the presence of a hemoglobin (Hb) variant. A new Gγ-globin variant was detected, namely Gγ105(G7)Leu → His; HBG2: c.317T > A, that we named Hb F-Brugine/Feldkirch after the place of origin of the two families. This T to A conversion results in a leucine to histidine amino acid change at codon 105 of the Gγ-globin gene and caused a Hb variant with lowered oxygen affinity. The γ to β switch proceeded normally.