Identification and molecular characterization of the --CAMPANIA deletion, a novel alpha (0) -thalassemic defect, in two unrelated Italian families [corrected]

Label-Free Optical Marker for Red-Blood-Cell Phenotyping of Inherited Anemias

The gold-standard methods for anemia diagnosis are complete blood counts and peripheral-smear observations. However, these do not allow for a complete differential diagnosis as that requires biochemical assays, which are label-dependent techniques. On the other hand, recent studies focus on label-free quantitative phase imaging (QPI) of blood samples to investigate blood diseases by using video-based morphological methods. However, when sick cells are very similar to healthy ones in terms of morphometric features, identification of a blood disease becomes challenging even with QPI. Here, we introduce a label-free optical marker (LOM) to detect red-blood-cell (RBC) phenotypes, demonstrating that a single set of all-optical parameters can clearly identify a signature directly related to an erythrocyte disease through modeling each RBC as a biological lens. We tested this novel biophotonic analysis by proving that several inherited anemias, such as iron-deficiency anemia, thalassemia, hereditary spherocytosis, and congenital dyserythropoietic anemia, can be identified and sorted, thus opening a novel route for blood diagnosis on a completely different concept based on LOMs.

Prenatal diagnosis of haemoglobinopathies: our experience of 523 cases

BACKGROUND

We performed counselling for prenatal diagnosis (PD) of haemoglobinopathies in 372 couples. Thirty-four out of 372 (9.1%) did not undergo PD: six due to spontaneous abortion; nine because it was too difficult to make a decision if PD was positive; 18 because counselling excluded the carrier status of one or both parents; and one because parental mutations were mild.

METHODS

Eleven out of 338 (3.3%) couples underwent PD because they had a thalassaemic child; 106 (31.4%) were found to be at high risk during pre-conceptional screening; 221 (65.4%) because of familiarity. Of 523 PDs in 486 (92.9%), including six dichorionic twin pregnancies, PD was performed on DNA from chorionic villi (CV), and in 37 from amniocytes (7.1%). In 1/523 cases, PD was not completed because DNA from CV was not sufficient; in two cases single tandem repeat analysis revealed maternal contamination of foetal DNA; in 7/522 (1.3%) cases PD revealed non-paternity. In 435/522 (83.3%) cases, PD was performed using reverse dot-blot and ARMS; 34/522 (6.5%) required sequencing. In 53/522 (10.2%) cases it was necessary to test globin loci for large rearrangements.

RESULTS

One hundred and twenty out of 522 (23.0%) PDs revealed an affected foetus. In all but two cases the couple interrupted pregnancy. In the six twin pregnancies PD revealed a normal and a carrier foetus (two cases), carrier status in both foetuses (two cases) and a carrier and an affected foetus (two cases). In these latter cases the couple planned selective interruption.

CONCLUSIONS

Our PD procedure is successful and reliable, and is useful in high-risk areas characterised by molecular heterogeneity.