The T?? Chain of Human Fetal Hemoglobin at Birth and in Several Abnormal Hematologic Conditions

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

“…The methods oftryptic hydrolysis, column chromatographic isolation of the yT-9 peptides (residues 67-76, inclusive), their amino-acid analysis, and the calculation of results have been described in detail (4) and were used without major modification. To assess the reproducibility of results within and between laboratories in Pasadena, Calif. and Augusta, In these experiments, the peptides TyT-9 and 'yT-9 were isolated in Pasadena, Calif., but portions were analyzed both in Pasadena, Calif. and Augusta, Ga. * Data from Pasadena, Calif.…”

Polymorphism of Foetal Haemoglobin in the Sardinian β⁺-Thalassaemia

“…These data suggest the presence of at least 2 /(+-thalassaemic chrom osom es in Sardinians, one associated with the variant AyT allele and one asso ciated with the norm al Ay*. The latter is prevalent am ong adult patients showing the interm ediate form of the thalassaem ic disease, which is not transfusion-dependent.The observation of the occurrence of the mutated Ay chain, known as the AyT chain, present in the socalled Hb F Sardinia (a 2A/ 275 lle-Thr) [3,5,13] in the foetal haem oglobin has been dem onstrated to be very im portant for our knowledge o f the genetics o f the ft gene cluster [5][6][7]14], The high incidence of the AyT al lele in various haematological disorders makes its product a m arker to be used for the evaluation o f the y chain production being in cis or in trans o f a particu lar gene [5], M oreover, a num ber of /) thalassaemia m utations have been found in chromosomes contain ing the AyT gene [2,4,9,16,18].In Sardinia, at least 2 main /(-thalassaemic genes coexist: the most com m on and widespread gene, characterized by a non-sense m utation at residue 39 [17], and the gene, present in the N orthern area of the island [8], not yet characterized at a m olecular lev el. It has already been described that the Sardinian fi°- , The linkage be tween the p° and the AyT genes has also been described in homozygous patients from the M editerranean and other areas [2, 5-7, 11, 14], Similarly, a strong linkage has been observed between the P+ and the Ay' genes in homozygous thalassaemic patients of intermediate severity from Algeria, Sicily, Tunisia and Portugal [2,16,18], The aim o f this work was to study the y chain com position of the foetal haemoglobin of Sardinian P+ -thalassaem ic patients in order to establish the pos sible linkage between the /J+ and the AyT genes in this population.…”

Composition of the <i>&#947;</i>-Chains of Human Fetal Hemoglobin at Birth and during Intrauterine Life

“…In the series of Huisman et al [9], "'/-chains have been found in 7 out of 10 /1-thalassemia homozygotes from Italy and Greece, in amounts ranging from 21 to 47% of the total /-chains. On the oth er hand, the Hb F from cord blood samples contains lower amounts of "'/-chains; in fact, in our series only 7 out of 18 newborns present about 10% of "'/-chains, and Huis man el al.…”

“…The same chain was detected in low percentages (about 10°/o) in only 40°/o of full-term newborns. Recently, Huisman et al [9] reported '/-chains in the Hb F of a large series of cord blood samples and of adults with several abnormal hematological conditions with a variable incidence in dif ferent racial groups.…”

“…However, the direct estimate of the number of human /-genes supports the existence of two, or at the most three /-genes for the human aploid genome [13]. On this basis, a new model with three /-genes, two °y (G and g) and one Ay, has been proposed [7,9].…”