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

• Main Authors: Abhay A Bhave, Lakshmi Iyer, Nawal Kazi, Manju Gorivale, Anita Nadkarni
• Format: Article
• Language: English
• Published: JCDR Research and Publications Private Limited 2021-03-01
• Series: Journal of Clinical and Diagnostic Research
• Subjects: : electrophoresis; haematocrit; mutation; oxygen affinity; polycythemia
• Online Access: https://www.jcdr.net/articles/PDF/14677/47560_CE[Ra1]_F[SK]_PF1(AKA_KM)_PFA(SHU_AKA)_PN(KM)_PFA2(OM)_PF2(AB_OM).pdf

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.