Neonatal screening: mean haemoglobin and red cell indices in cord blood from Omani neonates

The aim of this study was to validate the interpretation of red blood cell indices in complete blood count [CBC] and high performance liquid chromatography [HPLC] results on cord blood samples in consecutive Omani neonates. Cord blood samples from 7,837 neonates, were analysed with CBC and HPLC using the beta-thalassaemia short programme. Direct sequencing of abnormal samples with HbS, HbD, HbE and HbC was performed to validate the HPLC results. Additionally, in cases with HbA <10%, the beta-globin gene was directly sequenced for beta-thalassaemia mutation analysis. Overall, 4,042 subjects [51.58%] had normal HPLC [HbA 22.88 +/- 8.03; HbF 77.02 +/- 8.04], whereas the presence of Hb Barts in the remaining 3,795 cases [48.42%] indicated the presence of alpha-thalassaemia. No case of HbH was detected. In the former subgroup respectively, the mean Hb [15.38 +/- 2.04 g/dl] red blood cell [RBC] count [4.69 +/- 0.68 x 10[12]/l], Hct [50.5 +/- 7.18%], mean corpuscular volume [MCV] [107.66 +/- 7.75 fl], mean corpuscular haemoglobin [MCH] [33.31 +/- 4.07 pg], mean corpuscular haemoglobin concentration [MCHC] [30.98 +/- 3.44 g/dl], red cell distribution width [RDW] [17.01 +/- 2.17%] whereas, in the latter group with alpha -thalassaemia, it was [14.79 +/- 2.90 g/dl]; [5.09 +/- 0.77 x 10[12]/l]; [49.7 +/- 7.40%]; [97.29 +/- 13.8 fl]; [29.74 +/- 11.80 pg]; [30.39 +/- 3.6 g/dl], and [18.09 +/- 2.56%] respectively. DNA sequencing of samples with abnormal haemoglobin could validate the CBC and HLPC interpretations in all cases. This is the first study comparing the hemoglobin and red cell indices in the cord blood from newborn Omani subjects with those from other countries in the region, showing comparable results to those seen in Saudi neonates. The study also validates the CBC and HPLC interpretations of the cord blood red cell indices in the Omani neonate. The incidence of alpha-thalassaemia diagnosed by the presence of Hb Barts in cord blood of neonates was 48.42%

Beta-globin gene cluster haplotypes in Iranian patients with beta-thalassemia

Beta-globin gene cluster haplotypes are useful in diagnosis of particular molecular defects in Beta-thalassemia, prenatal diagnosis of Beta-thalassemia, and elucidating population affinities. Beta-globin gene cluster haplotypes were studied in 150 Beta-thalassemia minor and 52 healthy in-dividuals from the Fars province of Iran. DNA was extracted from leukocytes of whole blood by phe-nol-chloroform. Haplotype was determined by PCR-RFLP technique. There were 26 out of 150 with homozygous haplotypes. Haplotype I was found as the most prevalent haplotype among both patients and normal individuals. Out of 26 patients bearing homozy-gous haplotypes, 12 [46.2%] had typical haplotype I and 3 [11.5%] had atypical haplotype I. The prevalence of haplotype I in normal control subjects was around 43% [45 out of 104 Beta A chromo-somes]. The second prevalent haplotype was haplotypes V [15.4%] and III [15.4%] for homozygous patients and controls, respectively. The most frequent mutation in patients was IVS II.1 [G-->A] that was not linked to a single haplotype. IVS I.110 [G-->A] mutation was linked to haplotype I. Mutation in codon 30 [G -->A] was associated with haplotype V. Being Haplotype I the most prevalent haplotype in Beta-thal and BetaA chromosomes, implies that Beta-thalassemia mutations might have arisen in the chromosomal background common in the popula-tion, rather than due to selection pressure or gene flow [migration]. Patients with haplotype IX had the highest HbF levels compared to other haplotypes