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Polycythaemia associated with homozygosity for the abnormal haemoglobin Sherwood Forest (β104 (G6) Arg → Thr)
Author(s) -
Williamson D.,
Beresford C. H.,
Langdown J. V.,
Anderson C. C.,
Green A. R.
Publication year - 1994
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1111/j.1365-2141.1994.tb04852.x
Subject(s) - polycythaemia , heterozygote advantage , mutation , mutant , compound heterozygosity , loss of heterozygosity , medicine , biology , genetics , endocrinology , allele , gene
Summary. We describe a 22‐year‐old Pakistani male with polycythaemia associated with homozygosity for a highaffinity haemoglobin mutant, Hb Sherwood Forest. This haemoglobin variant has an amino acid substitution in the β globin chain at position 104, Arg → Thr. In the two previously reported instances of this haemoglobin mutant the individuals were heterozygotes and were haematologically normal. We show here that the homozygous state for the mutation is associated with a compensatory erythrocytosis resulting from decreased delivery of oxygen to the tissues. A family study showed that both parents and two siblings are heterozygotes for the haemoglobin mutant and are haematologically normal. To our knowledge, this represents the first example of a β‐globin mutation producing polycythaemia in homozygotes but not in heterozygotes.