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

Abstract

In 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.

• γ to β switch
• ^Gγ-globin variant
• low oxygen affinity
• neonatal cyanosis

Acknowledgements

We thank Dr. Urs Zimmermann (Clinic of Neonatology, Hospital Bülach, Bülach, Switzerland), Drs. Georg Reinhold and Ralph Capalo (Clinic of Neonatology, Cantonal Hospital Winterthur, Winterthur, Switzerland) and Dr. Woflgang Dietz (Landeskrankenhaus, Feldkirch, Austria) for providing blood samples and clinical information. Furthermore, we would like to thank Dr. Gabor Matyas (Center for Cardiovascular Genetics and Gene Diagnostics, Schlieren, Switzerland) for his help with saliva DNA extraction.