First observation of hemoglobin G-Norfolk in the Turkish population

Abstract

Objectives: Hemoglobinopathies are inherited transition blood diseases associated with globin chains of the hemo globin. However many mutations have been defined, there may be many of them not defined yet. We here report the first case of those mutations, named Hb G-Norfolk in Turkey. Case presentation: A 15 years-old male patient with erythrocytosis was referred to our laboratory for the eval uation of hemoglobinopathy. In chromatographic anal ysis, an unidentified peak was observed. A similar identification for variant Hb could not be obtained from High-Performance Liquid Chromatography (HPLC) ana lyzer’s data library. No definitive diagnosis could also be made by different analyzer. Family screening and molec ular genetic DNA sequence analysis were carried out. Conclusions: Although there were not found any beta gene mutation of neither the patient nor his family, ana lyses of alpha genes A1 and A2 were performed and abnormal hemoglobines were detected for all of them. This change in the HbA2 gene was at codon85 GAC>AAC (Asp>Asn) in the heterozygous state, known as Hb G-Norfolk [HbA2:c256G>A p.Asp85Asn] based on HbVar database. Abnormal Hb bands detected by HPLC with clinical findings such as erythrocytosis or cyanosis should be investigated by sequence analysis to corroborate alpha and/or beta-globin gene mutations for avoiding misdiagnosis and misinter pretation.