A Homozygote for the Hb_Gγ Type of Foetal Haemoglobin in India: A Study of Two Indian and Four Negro Families

Abstract

Summary. The haemoglobin of a 9‐yr‐old boy from the area of Bombay has only haemoglobin F. The γ‐chains of this haemoglobin F are solely of Gγ type, and the child is considered to be a homozygote for hereditary persistence of foetal haemoglobin of the Gγ type. The same kind of haemoglobin F is also present in a second Indian family and in four American Negro families. One Negro family has an appreciably lower percentage of haemoglobin F in heterozygotes than the other five families. In some of the families certain individuals also have haemoglobin E or haemoglobin S in trans to the other condition and haemoglobin A is absent. Although it has been concluded that the hereditary persistence of foetal haemoglobin is present the condition is not expressed uniformly in all these families. Some of them have certain characteristics of F‐thalassaemia. It is possible that two conditions are, in reality, represented: perhaps some families have the hereditary persistence of foetal haemoglobin and others have F‐thalassaemia.

Further studies of the frequency and significance of the Tgamma-chain of human fetal hemoglobin.

“…The data given in Fig. 6 Glycine in yCB-3 FIGURE 6 Relationship between the percentage of Ty-chain and the fraction of Some of the available data of Fig. 6 are difficult to explain because it cannot be determined with certainty into which category they belong.…”

The γ-Chain in a Ghanaian Adult, Homozygous for Hereditary Persistence of Fetal Haemoglobin

“…However, unrelated HPFH families from India who have so far been studied have been found to synthesise mainly °/-chains [14,15], and Sukumaran et al [14] be lieve that the Gy-type may be prevalent among the Asiatic Indians. This Hb type has also been reported in Negro families with HPFH [14], and all the ttyf-thalassaemia cases in individuals of Chinese origin [16], On the other hand, studies on Greek families with HPFH showed they had '/-chains with a complete suppression of the G/-locus [17], Similar ob servations have been made in HPFH patients from other Caucasian fami lies [11]. Our results indicate that in this homozygote from Accra the A/-locus is non-functional.…”

Balanced Globin Chain Synthesis in Hereditary Persistence of Fetal Hemoglobin

“…In the second family, the Hb F values are higher (20-30%) as described by Conley, Weatherall, Richardson, Shepard, and Charache (1). The two types of Hb F in black patients have been shown by Sukumaran et al (21) to contain different ratios of glycine and alanine at position 136 of the y chain. The presence of four y-producing genes, two synthesizing 136 alanine-containing ay chains (TA) and two 136 glycine-containing Y chains (-yG) has been postulated (22).…”