Haemoglobin Warwickshire (beta 5 [A2] Pro----Arg). A possible 'fine tuning' of 2,3-DPG affinity by beta 5 Pro

The blood of a 67-year-old Scotsman who was admitted to hospital with an abdominal carcinoma showed an abnormal red cell lysis in the oxidase channel of the Technicon H6000 analyser. This is seen regularly with Hb C and sometimes with Hb S and on further investigation a new haemoglobin variant--Hb Warwickshire--was found. When the family was examined, other examples were revealed. The haematological parameters were normal. Hb Warwickshire is mildly unstable and whilst in the absence of phosphates its oxygen dissociation does not differ from that of Hb A, a small fall of oxygen affinity is noted when phosphates are present.