Haemoglobin Olympia {β Codon 20 (B2) G→A, Val→Met}: A Silent Haemoglobin Variant

• Published in: Journal of clinical and diagnostic research Vol. 15; no. 3; pp. ED07 - ED09
• Main Authors: Bhave, Abhay A, Iyer, Lakshmi, Kazi, Nawal, Gorivale, Manju, Nadkarni, Anita
• Format: Journal Article
• Language: English
• Published: JCDR Research and Publications Private Limited 01.03.2021
• Subjects: electrophoresis; haematocrit; mutation; oxygen affinity; polycythemia
• ISSN: 2249-782X; 0973-709X
• DOI: 10.7860/JCDR/2021/47560.14677

High oxygen affinity haemoglobin variants are rare and often underdiagnosed in persistent erythrocytosis with no apparent aetiology. Here the author present a 29-year-old Indian male patient with a long-standing history of erythrocytosis which was incidentally detected. The proband had a prothrombotic family history of cerebral vessel stroke in his paternal grandfather at a young age and unexplained erythrocytosis in his father and brother. A review of his haemograms showed persistent high haemoglobin values. Routine tests did not reveal any specific aetiology and haemoglobin electrophoresis by High-Performance Liquid Chromatography (HPLC) showed absence of any abnormal peak or unstable haemoglobin. DNA sequencing of the β globin gene revealed heterozygosity for codon 20 {GTG→ATG, Valine (Val)→ Methionine (Met)} mutation confirming the presence of an electrophoretically silent Hb variant - Haemoglobin Olympia in him and his extended family members. This case study emphasises importance of this rare entity of high oxygen affinity haemoglobin variant as a differential diagnosis while screening for erythrocytosis. This is the first case report of Haemoglobin Olympia from India reported in the literature.