Hemoglobinopathies are the most common single-gene disorders in the world. Their prevalence is predicted to increase in the future, and low-income hemoglobinopathy-endemic regions need to manage most of the world's affected persons. International organizations, governments, and other stakeholders have initiated national or regional prevention programs in both endemic and nonendemic countries by performing population screening for α- and β-thalassemia, HbE disease, and sickle cell disease in neonates, adolescents, reproductive-age adults (preconceptionally or in the early antenatal period), and family members of diagnosed cases. The main aim of screening is to reduce the number of affected births and, in the case of sickle cell disease, reduce childhood morbidity and mortality. Screening strategies vary depending on the population group, but a few common screening test methods are universally used. We discuss the salient features of population-screening programs around the globe as well as current and proposed screening test methodologies.

Bone marrow (BM) mesenchymal stem/stromal cells (MSCs) are vital in hematopoiesis. Whether BM-MSCs alter their characteristics in Myelodysplastic Syndromes (MDS) is still controversial. We characterized MSCs of de novo MDS patients in Sri Lanka who have not been reported previously in the literature. We also analyzed MSCs derived from different MDS subtypes. MSCs were culture-expanded, characterized by flow cytometry, and induced towards osteogenic and adipogenic differentiation. Growth properties were determined using growth curves and population doubling times. Karyotyping and FISH were performed on MSCs. Cell morphology, differentiation potential, and CD marker expression of MDS-MSCs of all subtypes were comparable to those of control-MSCs. No significant growth differences were observed between control MSCs and MDS-MSCs of all subtypes (p > 0.05). 31% of MDS-MSCs had chromosomal aberrations (der(3),del(6q),del(7p), loss of chromosomes) whose BM karyotypes were normal. Highest percentage of karyotypic abnormalities was observed in RCMD-MSCs. Patients with abnormal BM karyotypes had no aberrant MSC clones. Results show that in spite of presence of genetically abnormal clones in MDS-MSC populations, in vitro phenotypic and growth characteristics of MSCs in MDS remain unchanged. Further, the occurrence of genetic abnormalities in BM-MSCs in MDS could be considered as an autonomous event from that of their hematopoietic counterparts.

Amniotic membrane (AM) due to its anti-inflammatory, anti-scarring and anti-angiogenic properties is used as corneal and wound grafts. When developing AM tissue banks, cell viability, membrane morphology and genomic stability should be preserved following cryopreservation. To analyze the changes rendered to the AM during the process of cryopreservation by comparing different combinations of standard cryopreservation media; fetal bovine serum (FBS), dimethyl sulfoxide (DMSO), Dulbecco's modified eagle's medium (DMEM) and glycerol at -80 °C and at -196 °C for a period of 6 weeks and at 4 °C in 70 % alcohol for 6 weeks. Following informed consent, placentae of healthy term pregnancies delivered by elective Cesarean section were collected and AM separated into 5 × 5 cm size sections and under sterile conditions stored in 9:1 DMSO:FBS and 1:1 DMEM:Glycerol at -196 and -80 °C for 6 weeks. Similar sections were also stored at 4 °C in 70 % alcohol for 6 weeks. After storage periods following were assessed; AM epithelial cell viability by trypan blue vital stain, epithelial cell proliferation capacity by cell doubling time, membrane morphology by haematoxylin and eosin (H&E) stain and genomic stability by conventional G-banded karyotyping. Human amniotic epithelial cells were cultured in DMEM and 10 % FBS in humidified atmosphere of 5 % carbon dioxide at 37 °C and were characterized using RT-PCR for Octamer-binding protein 4 (Oct-4) and glucose-6-phosphate dehydrogenase (G6PD) genes. All the above parameters were also assessed in fresh AM. AM obtained from 4 term placentae. Mean cell count and mean cell doubling times in days respectively; for fresh AM 3.8 × 10(6); 1.59, after 6 weeks in DMSO:FBS at -196 °C 3.0 × 10(6); 2.38 and at -80 °C 2.1 × 10(6); 1.60, in DMEM:Glycerol at -196 °C 3.6 × 10(6); 2.33 at -80 °C 23 × 10(6); 1.66 and at 4 °C 3.3 × 10(6); 2.14. Histology analysis of the fresh AM showed an intact epithelial monolayer, thick basement membrane (BM) and avascular stromal matrix. Amniotic membranes stored at -196 °C showed morphology similar to fresh AM in both preservation media and AM stored at -80 °C showed disruption of the stromal matrix. At 4 °C the epithelial monolayer showed flattening. Fresh AM karyotype was 46XX. Analyzable spreads for karyotype were not obtained from stored AMs. Human amniotic epithelial cells were positive for both Oct-4 and G6PD genes. AM is best preserved at -196 °C either in 1:9 DMSO:FBS or 1:1 DMEM:Glycerol. In both conditions cell viability and membrane integrity were shown to be preserved up to 6 weeks. Since analyzable chromosome spreads from cell cultures were not obtained, genomic stability could not be assessed.

Myelodysplastic syndromes (MDS) are a clonal hematopoietic stem cell (HSC) disorders. Cytogenetics plays a vital role in pathogenesis, diagnosis, prognosis, and determining treatments in MDS. Cytogenetic studies on CD 34 + cells in Asian MDS patients are limited. The aim of conducting this study was to compare the karyotypic features of CD 34 + cells and their bone marrow (BM) karyotypes. BM samples of 20 primary MDS patients were collected. BM-CD 34 + cells were isolated by CD34 positive selection. Conventional karyotyping was performed on primary BM samples and isolated CD 34 + cells. Fluorescence in situ hybridization (FISH) was performed to confirm del(5q) by using XL 5q31/5q33 locusspecific probe. Chromosomal abnormalities were detected in 41 % (7/17) of BM and 40 % (8/20) of HSC karyotypes. BM and HSC karyotypes were similar (94 %) except in one (BM-normal; CD 34+ cells had del(5q)) where the patient showed characteristic del(5q) phenotype. The abnormalities found were del(5q)-10 % (2/20), del(11q)-5 % (1/20), del(12p)-5 % (1/20), 47,XY,+19-5 % (1/20), hypodiploidy-5 % (1/20), and random loss of chromosomes-10 % (2/20). The percentage of abnormal metaphases counted per case was higher for CD 34 + cell cultures than for BM cultures. Culture failure were less for CD 34 + cells when compared to BM. Sample limitation for BM does not apply for CD 34 + cells if cultures can be maintained. Although the abnormal karyotypes counted were greater using CD 34 + cells than BM, there was no statistically significant difference (p > 0.05). Detection of karyotypic abnormalities could be greater when using CD 34 + cells. All the karyotypic abnormalities reported in this study had been previously known in MDS. Further large scale studies are needed to verify our findings.

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