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.

No abstract

In this article, we present the genomic DNA yield and the microsatellite and single nucleotide polymorphism (SNP) genotyping success rates of genomic DNA extracted from a large number of mouth swab samples. In total, the median yield and quality was determined in 714 individuals and the success rates in 378,480 genotypings of 915 individuals. The median yield of genomic DNA per mouth swab was 4.1 microg (range 0.1-42.2 microg) and was not reduced when mouth swabs were stored for at least 21 months prior to extraction. A maximum of 20 mouth swabs is collected per participant. Mouth swab samples showed in, respectively, 89% for 390 microsatellites and 99% for 24 SNPs a genotyping success rate higher than 75%. A very low success rate of genotyping (0%-10%) was obtained for 3.2% of the 915 mouth swab samples using microsatellite markers. Only 0.005% of the mouth swab samples showed a genotyping success rate lower than 75% (range 58%-71%) using SNPs. Our results show that mouth swabs can be easily collected, stored by our conditions for months prior to DNA extraction and result in high yield and high-quality DNA appropriate for genotyping with high success rate including whole genome searches using microsatellites or SNPs.

Although the amino acid substitution of this new variant is identical to that of HbS and shifted of a single amino acid position, no polymerization occurs in vitro. The sickle test is a valid method to confirm or exclude HbS trait in individual cases. Whenever the case is part of a possible couple at risk, then one has to use full DNA analysis in both partners not to miss hidden concomitant defects important for genetic risk predictions.

This explorative study showed that fairly pure autologous erythroid-expanded cell populations could be obtained by a simple culture method, which should be optimized. Future challenges comprise obtaining ex vivo enucleation of RBCs with the use of a minimal manipulating approach, which can add up to autologous RBCs derived from CB in the treatment of anemia of prematurity.