Organization of the ζ-α genes in Chinese

Abstract

Analysis of α and ζ genes in 101 healthy normals and hospitalized patients with non-haematological diseases revealed a 3% incidence of α thalassaemia in the local Chinese population of Hong Kong. Triple α genes were found in only one person while triple ζ genes were more prevalent, occurring in 13 subjects. Studies of 28 unselected patients with Hb H disease indicated a predominance of the rightward α gene deletion. The extent of α gene deletion in homozygous α thalassaemia 1 was at least 18.1 kb, beginning from the BamH I site 3' to the ζ1 gene and includes the ψα, α2 and α1 genes. Nineteen of the 20 chromosomes bearing the α thalassaemia 1 deletion had identical ζ-intergenic hypervariable region suggesting a common origin of this mutation. The co-inheritance of α thalassaemia in β thalassaemia subjects was 8%, but did not ameliorate the clinical features of those with homozygous β thalassaemia.