A New Hemoglobin Variant, Hb Natal (HBA1: c.423C>A), Found in a Greek Family.

The rare hemoglobin (Hb) variant Hb Natal [α140(HC2)Tyr-Arg→0 (HBA2: c.423C>A)], detected on the α2-globin gene, is characterized by a shortened polypeptide chain because of a premature stop codon formation in codon 140. Here, we report identification of the same genetic variation but in the corresponding position of the α1-globin gene, in a heterozygous state, in five members of a Greek family. All carriers of Hb Natal (ααNatal/αα) present with mild hematological and no clinical findings. This innocuous Hb variant was initially detected, in the context of the national prevention program for hemoglobinopathies, by high performance liquid chromatography (HPLC) and capillary electrophoresis (CE). Identification of the variant was performed by molecular analysis of the α-globin genes. This is the first description of a heterozygous Hb Natal in a Greek family, and the first description of this genetic variant on the HBA1 gene, worldwide.

Droplet Digital PCR for Non-Invasive Prenatal Detection of Fetal Single-Gene Point Mutations in Maternal Plasma.

Non-invasive prenatal testing (NIPT) is based on the detection and characterization of circulating cell-free fetal DNA (ccffDNA) in maternal plasma and aims to identify genetic abnormalities. At present, commercial NIPT kits can detect only aneuploidies, small deletions and insertions and some paternally inherited single-gene point mutations causing genetic diseases, but not maternally inherited ones. In this work, we have developed two NIPT assays, based on the innovative and sensitive droplet digital PCR (ddPCR) technology, to identify the two most common ß thalassemia mutations in the Mediterranean area (ß+IVSI-110 and ß039), maternally and/or paternally inherited, by fetal genotyping. The assays were optimized in terms of amplification efficiency and hybridization specificity, using mixtures of two genomic DNAs with different genotypes and percentages to simulate fetal and maternal circulating cell-free DNA (ccfDNA) at various gestational weeks. The two ddPCR assays were then applied to determine the fetal genotype from 52 maternal plasma samples at different gestational ages. The diagnostic outcomes were confirmed for all the samples by DNA sequencing. In the case of mutations inherited from the mother or from both parents, a precise dosage of normal and mutated alleles was required to determine the fetal genotype. In particular, we identified two diagnostic ranges for allelic ratio values statistically distinct and not overlapping, allowing correct fetal genotype determinations for almost all the analyzed samples. In conclusion, we have developed a simple and sensitive diagnostic tool, based on ddPCR, for the NIPT of ß+IVSI-110 and ß039 mutations paternally and, for the first time, maternally inherited, a tool, which may be applied to other single point mutations causing monogenic diseases.

BRCA1-BRCT Mutations Alter the Subcellular Localization of BRCA1 In Vitro.

BACKGROUND/AIM: Numerous missense mutations have been determined in the BRCT domain of the BRCA1 gene, affecting localization and interaction of BRCA1 with other proteins. MATERIALS AND METHODS: We examined whether the M1775K and V1809F mutations in the BRCT domain affect BRCA1 cellular localization. Cells were transfected with pEGFP-C3-BRCA1 and detected by fluorescence microscopy. RESULTS: Following induction of DNA damage, cytoplasmic mislocalization was observed for both M1775K and V1809F mutants compared to EGFP-BRCA1wt and the less common variant M1652I. These results indicate that M1775K and V1809F mutations may change the function of the protein by affecting BRCA1 localization. CONCLUSION: There is a correlation between subcellular localization of BRCA1 and diminished DNA repair observed in breast cancer cells, which may be explained by structural variations and altered binding properties of phosphopeptides.

First Report of a Coincidental Discovery of Hb Antibes-Juan-Les-Pins (HBB: c.349_350insGTGTGCTGGCCC) in a Greek Woman.

The rare Hb Antibes-Juan-Les-Pins (HBB: c.349_350insGTGTGCTGGCCC) was first reported in France. Hb Antibes-Juan-Les-Pins seems to be an innocuous variant and few published data are available. Heterozygous carriers have mild clinical or hematological findings. The abnormal hemoglobin (Hb) is detected by high performance liquid chromatography (HPLC) or capillary zone electrophoresis (CZE), but confirmation of the variant requires molecular analysis. This is the first description of Hb Antibes-Juan-Les-Pins heterozygosity in a woman of Greek origin.

Coinheritance of Triplicated Alpha-Globin Gene and Beta-Thalassemia Mutations in Adulthood: Ten Years of Referrals in Northern Greece.

Greece is a country of ~11 million people, where hemoglobinopathies are the most common genetic diseases. The reported data describe the clinical phenotype of cases with coinheritance of triplicated α-globin (anti-α3.7 kb) and ß-globin gene mutations in Northern Greece, that were referred within the last 10 years, in The Adult Thalassemia Unit of "Hippokration" Hospital, Thessaloniki, Northern Greece. The description of specific genotypes of the ß-globin gene mutations in coinheritance with the triplicated α-globin gene (anti-α3.7 kb) and correlation with the hematologic and clinical data in adulthood may be useful in the evaluation of pediatric patients' prognosis and in genetic counseling of couples at risk.

Detection of the sickle hemoglobin allele using a surface plasmon resonance based biosensor.

Sickle Cell Disease (SCD) is a monogenic hereditary blood disorder caused by a single point mutation (ßS) in the ß globin gene resulting in an abnormal hemoglobin (HbS) that can polymerize within the erythrocytes, inducing their characteristic sickle shape. This causes hemolytic anemia and occlusive vessels for the most severe clinical status. Molecular analysis is crucial for fast and precise diagnosis of different forms of SCD, and, on the basis of underlying genotype, for supporting the most appropriate treatment options. In this context, we describe a simple and reproducible protocol for the molecular identification of the ßS mutation based on surface plasmon resonance (SPR) using the Biacore™ X100 affinity biosensor. This technology has already demonstrated its diagnostic suitability for the identification of point mutations responsible for genetic diseases such as cystic fibrosis and ß thalassemia, using a protocol based on immobilization of PCR products on the sensor chip. On the contrary, in this work we applied a SPR strategy based on an innovative interaction format, recently developed in our group also for ß thalassemia mutations. In particular, we correctly detected the ßS mutation responsible for SCD, both in homozygous and heterozygous states, after hybridization of two oligonucleotide probes (normal and mutated) for the ßS mutation, immobilized on sensor chip, with unbalanced PCR products obtained from 53 genomic DNAs carrying different ßS allele combinations.

Efficacy of the National Thalassaemia and Sickle Cell Disease Prevention Programme in Northern Greece: 15-Year Experience, Practice and Policy Gaps for Natives and Migrants.

Hemoglobinopathies constitute the most frequent monogenic disorders worldwide and in Greece. In Greece, carrier frequency is estimated at about 8.0%, resulting in a heavy disease burden in the past. Therefore, the implementation of a national prevention program of the disease was an urgent necessity. Moreover, due to migration flow from different geographic areas in the last two decades, the observed spectrum of underlying mutations was expanded, leading to the adaptation of diagnostic approaches. We report the results of the National Thalassaemia Prevention Programme in Northern Greece, over a 15-year period (2001-2015). In total 33,837 healthy at-risk individuals (individuals or couples, 91.0% Greeks) were screened. We have screened 1598 pregnancies in 371 (23.0%) (10.0% non Greeks), of whom both parents carried gene defects and were offered genetic counseling. Seventy-six fetuses (23.0%) were predicted to be affected by severe forms of the disease. Following informed parental choices, 73 of the above pregnancies were terminated. Meanwhile, within the study period, 58 new thalassemic babies (five non Greeks) were referred to the Thalassaemia and Sickle Cell Disease Care Unit of Northern Greece, reflecting mostly parental unawareness, choice or the program failure. Based on the region's population, the birth rate and the prevalence of the disease, the anticipated number of new cases is about 45 annually. According to our data, four thalassemic newborns were registered annually at a stable rate in the last 15 years, reaching a reduction of 90.0% of new affected births. Overall, the National Thalassaemia Prevention Programme effectively decreased the incidence of affected newborns in our region.

Development of a High-Resolution Melting Approach for Scanning Beta Globin Gene Point Mutations in the Greek and Other Mediterranean Populations.

Beta-thalassaemia is one of the most common autosomal recessive disorders worldwide. The disease's high incidence, which is observed in the broader Mediterranean area has led to the establishment of molecular diagnostics' assays to prevent affected births. Therefore, the development of a reliable, cost-effective and rapid scanning method for ß globin gene point mutations, easily adapted to a routine laboratory, is absolutely essential. Here, we describe, for the first time, the development of a High-Resolution Melting Analysis (HRMA) approach, suitable for scanning the particularly heterogeneous beta globin gene mutations present in the Greek population, and thus adaptable to the Mediterranean and other areas where these mutations have been identified. Within this context, ß globin gene regions containing mutations frequently identified in the Greek population were divided in ten overlapping amplicons. Our reactions' setup allowed for the simultaneous amplification of multiple primer sets and partial multiplexing, thereby resulting in significant reduction of the experimental time. DNA samples from ß-thalassaemia patients/carriers with defined genotypes were tested. Distinct genotypes displayed distinguishable melting curves, enabling accurate detection of mutations. The described HRMA can be adapted to a high-throughput level. It represents a rapid, simple, cost-effective, reliable, highly feasible and sensitive method for ß-thalassaemia gene scanning.

Engineered strains of Streptococcus macedonicus towards an osmotic stress resistant phenotype retain their ability to produce the bacteriocin macedocin under hyperosmotic conditions.

Streptococcus macedonicus ACA-DC 198 produces the bacteriocin macedocin in milk only under low NaCl concentrations (<1.0%w/v). The thermosensitive plasmid pGh9:ISS1 was employed to generate osmotic stress resistant (osmr) mutants of S. macedonicus. Three osmr mutants showing integration of the vector in unique chromosomal sites were identified and the disrupted loci were characterized. Interestingly, the mutants were able to grow and to produce macedocin at considerably higher concentrations of NaCl compared to the wild-type (up to 4.0%w/v). The production of macedocin under hyperosmotic conditions solely by the osmr mutants was validated by the well diffusion assay and by mass spectrometry analysis. RT-PCR experiments demonstrated that the macedocin biosynthetic regulon was transcribed at high salt concentrations only in the mutants. Mutant osmr3, the most robust mutant, was converted in its markerless derivative (osmr3f). Co-culture of S. macedonicus with spores of Clostridium tyrobutyricum in milk demonstrated that only the osmr3f mutant and not the wild-type inhibited the growth of the spores under hyperosmotic conditions (i.e., 2.5%w/v NaCl) due to the production of macedocin. Our study shows how genetic manipulation of a strain towards a stress resistant phenotype could improve bacteriocin production under conditions of the same stress.

Pregnancy in beta-thalassemia intermedia: 20-year experience of a Greek thalassemia center.

OBJECTIVE: Progress in the management of patients with thalassemia intermedia (TI) enabled increasing rates of pregnancies among TI women worldwide. Nevertheless, information regarding TI pregnancy management and outcome is quite limited in the literature. The aim of this study was to report our experience regarding the maternal and fetal outcome of TI patients, as well as to depict the complexity of the disease and the need for multidisciplinary and personalized management as shown by the description of two interesting pregnancy cases. METHODS: We analyzed our data recorded from 60 pregnancies in 34 women over a 20-yr period. RESULTS: Forty-nine patients achieved full-term pregnancies (mean maternal age ± SD: 27.4 ± 6.5 yr) within 37 ± 3 gestation weeks. Their mean hemoglobin value was 8.33 ± 1.22 g/dL; 26.5% of patients were not transfused at all or they had been transfused only once during gestation. There were 11 abortions (18.3%). The spontaneous abortions (5/11) were related to high HbF levels. Six patients had more than two normal deliveries. Nineteen newborns (38.8%), which weighed 2-3 kg, required hospitalization to an intensive neonatal care unit for 1-3 wk. One patient presented with life-threatening complications (hemolytic anemia, thrombocytopenia, and enlargement of spleen) and another with spastic paraparesis due to extramedullary paravertebral masses. CONCLUSIONS: Although several complications can occur during a pregnancy in TI women, the careful and frequent monitoring by both hamatologists and obstetricians can lead to successful deliveries.

In silico evidence for the horizontal transfer of gsiB, a σ(B)-regulated gene in gram-positive bacteria, to lactic acid bacteria.

gsiB, coding for glucose starvation-inducible protein B, is a characteristic member of the σ(Β) stress regulon of Bacillus subtilis and several other Gram-positive bacteria. Here we provide in silico evidence for the horizontal transfer of gsiB in lactic acid bacteria that are devoid of the σ(Β) factor.

Comparative and evolutionary analysis of plasmid pREN isolated from Lactobacillus rennini, a novel member of the theta-replicating pUCL287 family.

Here, we describe plasmid pREN of Lactobacillus rennini ACA-DC 1534, isolated from traditional Kopanisti cheese. pREN is a circular molecule of 4371 bp. Orf calling revealed a novel repA-orf2 operon with the deduced product of orf2 showing no similarity to other known proteins. Downstream of this operon, a gene cluster encoding different mobilization proteins, namely mobC, mobA1, mobA2 and mobB, was detected. Based on the sequence of the origin of replication (ori) and the similarity pattern of RepA, pREN was placed in the pUCL287 family of theta-replicating plasmids. Multiple sequence alignment demonstrated for the first time the degree of conservation in the pUCL287 oris. Our analysis supported that the identified conserved repeats could drive similar secondary structures in the oris of all plasmids. Furthermore, comparative mapping of pREN with its related plasmids (i.e. pLB925A03 and pLJ42) showed that they retain a unique combination in the architecture of their replication and mobilization elements within the pUCL287 family. Phylogenetic analysis also established that these plasmids have undergone a modular evolutionary process in order to acquire their mob genes. Research on plasmids from uncommon lactic acid bacteria will expand our appreciation for their divergence and will aid their rational selection for biotechnological applications.

Characterization of pLAC1, a cryptic plasmid isolated from Lactobacillus acidipiscis and comparative analysis with its related plasmids.

The pLAC1 plasmid of Lactobacillus acidipiscis ACA-DC 1533, a strain isolated from traditional Kopanisti cheese, was characterised. Nucleotide sequence analysis revealed a circular molecule of 3478bp with a G+C content of 37.2%. Ab initio annotation indicated four putative open reading frames (orfs). orf1 and orf4 were found to encode a replication initiation protein (Rep) and a mobilization protein (Mob), respectively. The deduced products of orf2 and orf3 revealed no significant homology to other known proteins. However, in silico examination of the plasmid sequence supported the existence of a novel operon that includes rep, orf2 and orf3 in pLAC1 and that this operon is highly conserved also in plasmids pLB925A02, pSMA23, pLC88 and pC7. RT-PCR experiments allowed us to verify that these three genes are co-transcribed as a single polycistronic mRNA species. Furthermore, phylogenetic analysis of pLAC1 Rep and Mob proteins demonstrated that they may have derived from different plasmid origins, suggesting that pLAC1 is a product of a modular evolution process. Comparative analysis of full length nucleotide sequences of pLAC1 and related Lactobacillus plasmids showed that pLAC1 shares a very similar replication backbone with pLB925A02, pSMA23 and pLC88. In contrast, mob of pLAC1 was almost identical with the respective gene of plasmids pLAB1000, pLB4 and pPB1. These findings lead to the conclusion that pLAC1 acquired mob probably via an ancestral recombination event. Our overall work highlights the importance of characterizing plasmids deriving from non-starter 'wild' isolates in order to better appreciate plasmid divergence and evolution of lactic acid bacteria.

RNA arbitrarily primed PCR and fourier transform infrared spectroscopy reveal plasticity in the acid tolerance response of Streptococcus macedonicus.

We have previously reported that an acid tolerance response (ATR) can be induced in Streptococcus macedonicus cells at mid-log phase after autoacidification, transient exposure to acidic pH, or acid habituation, as well as at stationary phase. Here, we compared the transcriptional profiles of these epigenetic phenotypes, by RNA arbitrarily primed PCR (RAP-PCR), and their whole-cell chemical compositions, by Fourier transform infrared spectroscopy (FT-IR). RAP-PCR fingerprints revealed significant differences among the phenotypes, indicating that gene expression during the ATR is influenced not only by the growth phase but also by the treatments employed to induce the response. The genes coding for the mannose-specific IID component, the 1,2-diacylglycerol 3-glucosyltransferase, the 3-oxoacyl-acyl carrier protein, the large subunit of carbamoyl-phosphate synthase, and a hypothetical protein were found to be induced at least under some of the acid-adapting conditions. Furthermore, principal component analysis of the second-derivative-transformed FT-IR spectra segregated S. macedonicus phenotypes individually in all spectral regions that are characteristic for major cellular constituents like the polysaccharides of the cell wall, fatty acids of the cell membrane, proteins, and other compounds that absorb in these regions. These findings provide evidence for major changes in cellular composition due to acid adaptation that were clearly different to some extent among the phenotypes. Overall, our data demonstrate the plasticity in the ATR of S. macedonicus, which reflects the inherent ability of the bacterium to adjust the response to the distinctiveness of the imposed stress condition, probably to maximize its adaptability.