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.

Rare Pathogenic ß0-Thalassemia Mutation, Codon 7 (GAG>TAG) (HBB: c.22G>T). Report of the First Two Cases in Albanian Immigrants of Northern Greece.

We report the hematological data of the codon 7 (GAG>TAG (HBB: c.22G>T) mutation for the first time in two Albanian individuals from the region of Elbasan, who underwent genetic testing due to prenatal counseling and diagnosis for ß-thalassemia major (ß-TM) anemia. The phenotype was compatible with a typical ß0-thalassemia (ß0-thal) carrier but the hematological findings of the mutation has not been previously reported. The mutation involves the conversion of codon 7 GAG (Glu) into a translation termination codon (TAG), involving the replacement of guanine by thymine so that no ß chains are produced.

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.

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.

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.

Longitudinal follow-up of exocrine pancreatic function in pancreatic sufficient cystic fibrosis patients using the fecal elastase-1 test.

BACKGROUND: A progressive decline in pancreatic function is possible in cystic fibrosis (CF) patients with exocrine pancreatic sufficiency. The secretin-cholecystokinin test is invasive and not acceptable as a repeatable procedure for children. Steatorrhea, conversely, has low sensitivity. Therefore, the aim of the present study was to evaluate the usefulness of the noninvasive fecal elastase-1 (E1) test for the longitudinal assessment of exocrine pancreatic function (EPF) in pancreatic-sufficient (PS) CF patients. METHODS: One hundred eighty-four CF patients were included in the study. In all subjects, E1 concentrations and fecal fat excretion were measured. PS patients were followed for 5 years. RESULTS: At the beginning of the study, 35 (19.0%) CF patients were PS, and 32 (17.4%) had normal E1 concentrations. Longitudinal measurements of E1 concentrations in PS patients with CF demonstrated stable enzyme output in 27 and gradual decrease in 8. The decrease was rapid in five infant patients and gradual in three older patients. The decrease of E1 concentrations preceded the appearance of steatorrhea in all eight subjects. CONCLUSIONS: The decline of EPF in patients with CF appears more frequently during the first months and years of life. However, late PS to pancreatic-insufficient (PI) conversion is also possible. The appearance of maldigestion is preceded by the decrease of fecal E1 concentration. Thus, the fecal E1 test is a helpful screening tool for the longitudinal assessment of declining EPF in PS patients with CF to demonstrate pancreatic deterioration. In suspected patients, fecal fat excretion should be assessed.