Internal Medicine
Online ISSN : 1349-7235
Print ISSN : 0918-2918
ISSN-L : 0918-2918
A Japanese Family with Congenital Erythrocytosis Caused by Haemoglobin Bethesda
Shinobu TamuraTadahiko TamuraHiroya GimaAkinori NishikawaYukiharu OkamotoNobuo KanazawaLuis RelvasElizabete CunhaMary Frances McMullinCeleste Bento
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2015 Volume 54 Issue 18 Pages 2389-2393


We herein present a case of congenital erythrocytosis caused by haemoglobin (Hb) Bethesda in a Japanese family. A 55-year-old asymptomatic man was referred to our hospital for the investigation of erythrocytosis, which was present in other members of his family. The patient's serum erythropoietin level was normal, and the JAK2 V617F mutation was not detected. His P50 value was mildly decreased, thus we suspected the presence of an Hb variant with a high oxygen affinity. The high-performance liquid chromatography analysis showed an abnormal Hb, and by direct sequencing we identified the Hb Bethesda variant in this patient. For the differential diagnosis, we recommend the estimation of the P50 value as a practical and useful test.

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© 2015 by The Japanese Society of Internal Medicine
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