We have tested five haemoglobin (Hb) separation apparatuses, dedicated to haemoglobinopathy diagnostics. These are the four high performance liquid chromatography devices: VARIANT II, HA 8160, G7, Ultra(2) and the Capillary Electrophoresis apparatus from Sebia. In the first place, we focussed on the capacity of all apparatuses to detect the most common structural variants relevant for public health, these being HbS, HbC, HbE, HbD-Punjab and HbO-Arab. We then compared how the high HbA(2)beta-thalassaemia carriers were identified. All apparatuses were able to identify carriers of these traits with the expected sensitivity and specificity. With the primary goal of a high degree of conformity in basic diagnostics of haemoglobinopathies, we present the interpretation and the significance of the results on all apparatuses, and we comment on the unavoidable problems and solutions.

We present the characterization of the molecular spectrum and frequency data of alpha-thal (thal) defects in Tunisia, and an evaluation of the efficacy and limitations of Hb Bart's (gamma4) measurement for the screening of alpha-thal at birth. Cord blood samples were collected from two different areas: the northeast of the country, an area where Hb H (beta4) disease frequently occurs, and Tunis, the capital city, representative of the average Tunisian population. From the first group, 110 samples with Hb Bart's and/or microcytosis at birth were selected from 1270 randomly collected samples. Two additional population samples, one from the same northeastern region (n = 90), the other from Tunis (n = 104) were collected randomly. Nine common deletional alpha-thal defects and nondeletional mutations were screened. In the northeastern samples, selected for the presence of Hb Bart's and microcytosis, the -alpha3.7 deletion was the most common defect (4.5% allele frequency) followed by a polyadenylation (poly A) signal mutation (1.8%), the five nucleotide (nt) deletion and the -alpha4.2 deletion (both 0.9%). The African polymorphism (G-->TCGGCCC at position 7238 and T-->G at 7174) was found with an allele frequency of 11% in the selected northeastern samples. In the random population samples, the overall alpha-thal allele frequency was 4% in the northeast region, against 2% in the average Tunisian population. The +14 (G-->C) polymorphism in the 5'UTR (untranslated region) of the alpha2 gene and the African polymorphism in the second intron of the same gene, were found in 3.5% of the alleles. No alpha0-thal alleles were found among the 304 blood samples studied at the DNA level during this survey.

We describe the molecular spectrum of a-thalassemia mutations in a population sample of newborns in the South-Iranian province of Hormozgan. Out of 660 randomly collected blood samples 218 (33%) had visibly elevated Hb Bart's. DNA was extracted from 78 samples out of this selection (n = 156), of which 114 alleles were found to carry an a-thalassemia defect. Besides the common -a 3.7 (79.1%), -a 4.2 (1.7%), and a -5nt a alleles (4.3%), three novel nondeletional a-thalassemia mutations were found; the a 2 cd19 (-G) frameshift mutation (12.2%), the a 1 IVS1-148(A?G) (0.9%) affecting the splice acceptor site consensus sequence and the cd14 (TGG?TAG) (0.9%), which creates a premature stop codon in the first exon of the a 1 -gene. A fourth mutation in the a 1 -gene, the IVS1-38 (C?T) (0.9%) of undetermined effect, was found in an individual heterozygous for the a 2 cd19(-G) mutation. Am.

The paper reports the results obtained from the study of 949 patients examined for a suspected alpha- or beta-thalassaemia using a rapid modified method of in vitro biosynthesis determination. Part of the results have been evaluated in correlation with the different molecular defects, defects combinations and with the presence of abnormal haemoglobins. The validity of the method for diagnosis of thalassaemia and particularly for the analysis of complex defects combinations which may occur in multiethnic populations is illustrated. The technology of the modified method is thoroughly described and the influence of the factors interfering with the reliability of the experiments is discussed.

The prevalence at birth of hemoglobin defects in the autochthonous North-European population is low. However, the long immigration and colonial history of the Netherlands has resulted in a group of about 1–2 million ‘autochthonous‘ inhabitants, with Asian, South-European or African ancestors, in whom a moderate birth prevalence of globin gene mutations can be expected. Furthermore, at least 10% of the Dutch population consists of recent immigrants from different countries with high birth prevalence of hemoglobinopathies. Because of the endogamous partner choice, which is prevalent in this population, the risk for homozygous progeny remains elevated. At least 100,000 carriers of hemoglobinopathies of recent allochthonous origin are present in the Netherlands, and the number of homozygous children is rising. Prevention by prenatal diagnosis requires a suitable protocol and knowledge about the molecular defects present in the country. Therefore we have analyzed a large number of patients and carriers, both at the hematological and at the DNA level. Our survey revealed 47 different β-thalassemia determinants, characterized on 223 independent chromosomes from individuals of different ethnic origins. As expected, the most prevalent mutations were largely represented. The cd39 (C→T) mutation was found in 70% of the immigrants from Morocco, Sardinia and other Central-West-Mediterranean regions while the IVS-I-110 (G→A) was prevalent in the East-Mediterranean populations. The IVS-I-5 (G→C) mutation was found in 45% of the patients of Indonesian origin. We also registered 308 independent chromosomes with common structural defects (HbS, HbC, HbE, Hb Lepore, Hb Constant Spring and HbD Punjab) and 33 chromosomes with 19 different, less frequent, rare or very rare mutants. Seven structural mutants were described for the first time and published separately. Furthermore, 139 independent chromosomes with deletional and nondeletional α-thalassemia defects were characterized.