Molecular characterization of Hb S(C) beta-thalassemia in American blacks.

An extension of previous reports describing the molecular defects and hematological abnormalities in black patients with Hb S(C) beta-thalassemia living in the Southeastern United States is presented. As many as 58 patients with Hb S-beta(+)-thalassemia, 16 with Hb C-beta(+)-thalassemia and 12 with Hb S-beta(0) -thalassemia have been studied. Patients with Hb S(C) beta(+)-thalassemia type 2 (high Hb A values) were most common; the thalassemia was due to mutations in the promoter of the beta-globin gene [-88 (C----T) and -29 (A----G)] or at the polyadenylation signal (T----C).

Hb Icaria-Hb H disease: identification of the Hb Icaria mutation through analysis of amplified DNA.

Hb Icaria-Hb H disease was observed in a Yugoslavian teenager who exhibited moderate anaemia with severe microcytosis and hypochromia and 16% Hb H. Four of his relatives were Hb Icaria heterozygotes; their haematological data were comparable to those with a deletional type of alpha-thalassaemia-2. The patient also had an additional alpha-thalassaemia-1 deletion, an approximately 20.

Molecular characterization of beta-thalassaemia in 174 Greek patients with thalassaemia major.

The mutations producing beta-thalassaemia in 174 Greek patients with thalassaemia major were investigated by dot-blot hybridization of oligonucleotide probes to genomic DNA amplified by the polymerase chain reaction procedure, by direct sequencing of amplified DNA, and by gene mapping. beta-thalassaemia in Greeks was found to be very heterogeneous at the molecular level as 17 different mutations were observed: 86.6% of the beta-thalassaemic genes, however, could be identified with five probes: IVS-I-110 (G----A) (42.

Abnormal processing of beta-Malay globin RNA.

Hemoglobin Malay (alpha 2 beta 2 19 Asn----Ser) has been observed in a few Malaysian patients with thalassemia intermedia. The beta Malay substitution increases the homology of the cryptic splice site at codons 17/18/19 of the beta-globin gene to the donor consensus splice sequence, suggesting that the beta-thalassemia associated with this mutation may be due to the generation of a new splice site. To test this hypothesis, we constructed a hybrid gene where we replaced part of a normal beta-globin gene with a PCR amplified region of the beta Malay gene.

beta S-haplotypes and alpha-thalassemia along the coastal belt of Kenya.

In this paper, we present data on studies of beta S-haplotypes and alpha-thalassemia gene in subjects from the indigenous population of the Coast Province of Kenya Of the 7SS patients studied, four were homozygous for beta S-haplotype 20 characteristically associated with the severe form of sickle cell anemia found in the Central African Republic and Western Kenya. Two had haplotype 20 combined with haplotype 19 (Benin Type) and one had haplotype 20 combined with a new haplotype (20x). Alpha thalassaemia-2 gene (-3.