Hb K Woolwich the cause of a thalassaemia

'Silent' beta-thalassaemia caused by a 'silent' beta-chain mutant: the pathogenesis of a syndrome of thalassaemia intermedia

In a Greek family three cases of beta-thalassaemia intermedia were diagnosed as resulting from the interaction of a typical high HbA2-beta-thalassaemia with an atypical (silent) beta-thalassaemia gene. Following electrophoresis of globins on an acid-urea-Triton-acrylamide system, an otherwise silent beta-like variant was revealed in the carriers of the atypical thalassaemia gene and in the intermediates; it amounted to 33% of the non-alpha chains in the former and to c. 75% in the latter. The provisional name Hb Knossos is suggested for this abnormality.

Haemoglobin K Woolwich: a study of the family of a homozygote

A family is described in which the proband is homozygous and several relatives are heterozygous for Hb K Woolwich (beta 130 [H10] Lys leads to Gln). These people are clinically and haematologically normal. The relationship between the presence of Hb K Woolwich and beta +-thalassaemia is discussed. The distribution of Hb K Woolwich in West Africa is discussed and it is seen to be closely associated with the Akan group.

Variation in hemoglobin A2

The structure, properties and function of, and some biosynthetic and genetic aspects of, Hb A2 are described. The structural variants of Hb A2 are reviewed and their geographical distribution presented. Hb A2, Hb A2-Flatbush and Hb A2-Babinga are characteristic of negro populations and may have originated in Western or Central Africa. Hb A2-Sphakia is characteristic of Canadian Amerindian and Hb A2-Indonesia of Indonesian/Malay populations. Hb A2-NYU has only been found sporadically and most frequently in persons of Eastern European origin. The other three variants of Hb A2 have only been reported in a single person or in single families. Some conditions which are associated with changes in Hb A2 levels are reviewed.

Is haemoglobin G alpha Philadelphia linked to alpha-thalassaemia?

The question, "Is Hb G alpha Philadelphia linked to alpha-thalassaemia?" was first posed because the abnormal haemoglobin is found in heterozygotes at a concentration greater than 25%, the proportion predicted from a 4 alpha-chain gene model. Globin chain biosynthesis was studied in a West Indian family in which one parent had beta + thalassaemia and the other was heterozygous for the G alpha Philadelphia chain gene. The former had a globin chain production ratio alpha/beta well above 1, while the latter had a ratio significantly less than 1. One child of the marriage had inherited the beta + thalassaemia from one parent and the G alpha Philadelphia chain gene from the other and showed the typical picture of alpha/beta-thalassaemia (alpha/beta ratio slightly above normal). It is explained in the discussion that the evidence favours a close linkage of 2 alpha-chain genes.