Hb AHVAZ [α83(F4)Leu→Arg, CTG>CGG (α2); HBA2: c.251T>G],a new hemoglobin variant of the α2-globin gene.

We report a novel mutation on the α2-globin gene, codon 83 (T>G), which was detected in two members of two unrelated families from Khuzestan Province, South Iran, that we named Hb Ahvaz. This mutation was detected by cellulose acetate electrophoresis and characterized by molecular studies. Hb Ahvaz does not seem to be responsible for hematological abnormalities in the carriers, but with α(0)-thalassemia (α(0)-thal) defects, might induce severe clinical symptoms.

A novel alpha-thalassemia nonsense mutation in HBA2: C.382 A > T globin gene.

In this study, a new alpha globin gene mutation on the α2-globin gene is reported. This mutation resulted in a Lys > stop codon substitution at position 127 which was detected in four individuals (three males and one female). DNA sequencing revealed this mutation in unrelated persons in Khuzestan province, Southwestern Iran of Lor ethnicity. This mutation caused no severe hematological abnormalities in the carriers. From the nature of substituted residues in α2-globin, it is widely expected that this mutation leads to unstable and truncated protein and should be detected in couples at risk for α-thalassemia.

Identification of IVS-I (-1) (G > C) or Hb Monroe as a report on the beta-globin gene with a beta-thalassemia minor phenotype in south of Iran.

We described the first report of IVS-I (-1), codon 30 (G > C) or Hb Monroe in five individuals from four unrelated families in Khuzestan Province. Polymerase chain reaction (PCR) followed by sequencing of the beta-globin gene confirmed the presence of Hb Monroe in the heterozygous form which causes beta-thalassemia due to missplicing in the course of mRNA processing. This mutation has been described in individuals originated from Arabic and Behbahani origins, Ahvaz City, south of Iran. The knowledge of the beta-globin variants present in the Iranian population is essential for the molecular diagnosis and prevention of hemoglobinopathies.

Co-inheritance of alpha-and beta-thalassemia in Khuzestan Province, Iran.

BACKGROUND AND AIMS: beta-thalassemia is one of the most frequent hemoglobinopathies and single gene disorders in Iran. About 13 beta globin mutations encompass 70-90% of mutations spectrum in Iran, the rest are rare or unknown. People who do not produce enough alpha globin protein chains have alpha-thalassemia. This is commonly found in Africa, the Middle East, India, Southeast Asia, southern China, and occasionally the Mediterranean region. There are normally four alpha globin genes, two on each chromosome 16. Individuals who have one or two abnormal alpha globin genes have alpha-thalassemia trait. The aim of this study was to detect alpha-thalassemia in beta-thalassemia carriers during prenatal screening. MATERIALS AND METHODS: A total of 158 couples were diagnosed to be discordant alpha- and beta-thalassemia carriers. We used the routine screening for thalassemia which includes full blood counts and indices, hemoglobin electrophoresis and measurement of Hb A(2) level. The standard diagnostic marker for beta-thalassemia is elevation of the Hb A(2) level (>3 x 5%). Low mean corpuscular volume (MCV) and mean cell hemoglobin (MCH) with a normal Hb A(2) indicate an alpha-thalassemia carrier. Staining for HbH inclusion bodies is also carried out as part of the screening for alpha thalassemia. The 59 and 39 ends of the breakpoint regions of the -alpha(4 x 2) allele and the normal homologous segments were sequenced in selected individuals. RESULTS: Of the 158 beta-thalassemia partners, seven (4 x 4%) were found to have co-inheritance of alpha(+)-thalassemia, and three (1 x 9%) found to have co-inheritance of alpha(0)-thalassemia. Two pregnancies affected with Hb Bart's hydrops fetalis were terminated in the 158 couples. A sequence haplotype was found in all of the five Iranian -alpha(4 x 2) thalassaemia alleles studied. Based on these findings, a novel polymerase chain reaction (PCR)/denaturing high performance liquid chromatography (DHPLC) assay was developed for rapid genotyping of the -alpha(4 x 2) allele instead of traditional Southern blotting or Gap-PCR. This method involves amplification of the alpha globin target sequence encompassing these four polymorphic sites, followed by a partially denaturing HPLC analysis using the transgenomic WAVE DNA fragment analysis system. The major genotypes (-alpha(4 x 2)/alpha alpha, -alpha(4 x 2)/--(MED), -alpha(3 x 7)/alpha alpha, -alpha(3 x 7)/-alpha(3 x 7), alpha alpha/--(MED) and alpha alpha/alpha alpha) could be distinguished through the characteristic chromatograms generated by the WAVE system. DISCUSSION: The results showed that molecular analysis must be used for accurate diagnosis of double heterozygotes in couples presumed to be discordant for alpha- and beta-thalassemia on hematologic testing. The accuracy of this technique was evaluated blindly, and the results were 100% (40 of 40) concordant with the genotypes previously characterized by Southern blotting or Gap-PCR.