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Hb H disease in a Turkish family resulting from the interaction of a deletional α‐thalassaemia‐1 and a newly discovered poly A mutation
Author(s) -
Yuuregir G. T.,
Aksoy K.,
ÇUuruuk M. A.,
Dikmen N.,
Fei Y.J.,
Baysal E.,
Huisman T. H. J.
Publication year - 1992
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.1365-2141.1992.tb04568.x
Subject(s) - mutation , genetics , turkish , hemoglobinopathy , medicine , thalassemia , biology , disease , gene , philosophy , linguistics
Summary We have analysed the α‐globin gene defects present in several members of a large family from Southern Turkey. One deletional α‐thalassaemia‐1 (type MED‐II) was found in 10 subjects; this deletion is in excess of 26.5 kb and includes all and α‐globin genes. Besides the common types of deletional α‐thalassaemia‐2 (—3.7 kb and —4.2 kb) we observed a nondeletional α‐thalassaemia‐2 that results from an AG mutation (AATAAAÁTGAA) in the polyadenylation signal of the α2‐globin gene; the same AG replacement is present in the Ψαl gene. The mutation must cause a considerable α‐chain deficiency as is evidenced by the haematological data for five members with Hb H disease due to a compound heterozygosity for α‐thalassaemia‐1 (MED‐II) and the newly discovered poly A mutation. Several members had additional β‐chain abnormalities (Hb S, Hb D‐Los Angeles, β‐thalassaemia); the 11 persons with a Hb S heterozygosity and various α‐globin gene defects (—α/αα; α T α/αα, ——/αα, —α/—α and ——/α T α) showed a decrease in the level of Hb S that was directly related to the severity of the α‐chain deficiency.