Functional analysis of three new alpha-thalassemia deletions involving MCS-R2 reveals the presence of an additional enhancer element in the 5' boundary region.

We report three novel deletions involving the Multispecies Conserved Sequences (MCS) R2, also known as the Major Regulative Element (MRE), in patients showing the α-thalassemia phenotype. The three new rearrangements showed peculiar positions of the breakpoints. 1) The (αα)ES is a telomeric 110 kb deletion ending inside the MCS-R3 element.

Alpha-Thalassemia in Southern Italy: Characterization of Five New Deletions Removing the Alpha-Globin Gene Cluster.

α-thalassemia is characterized in about 80% of cases by deletions generated by the presence of duplications and interspersed repeated sequences in the α-globin gene cluster. In a project on the molecular basis of α-thalassemia in Southern Italy, we identified six families, showing an absence of the most common deletions, and normal α-globin gene sequences. Multiplex Ligation-dependent Probe Amplification (MLPA), qRT-PCR, and the sequencing of long-range PCR amplicon have been used for the identification and characterization of new deletions.

ADP-Ribosylation Post-Translational Modification: An Overview with a Focus on RNA Biology and New Pharmacological Perspectives.

Cellular functions are regulated through the gene expression program by the transcription of new messenger RNAs (mRNAs), alternative RNA splicing, and protein synthesis. To this end, the post-translational modifications (PTMs) of proteins add another layer of complexity, creating a continuously fine-tuned regulatory network. ADP-ribosylation (ADPr) is an ancient reversible modification of cellular macromolecules, regulating a multitude of key functional processes as diverse as DNA damage repair (DDR), transcriptional regulation, intracellular transport, immune and stress responses, and cell survival.

mRNA Analysis of Frameshift Mutations with Stop Codon in the Last Exon: The Case of Hemoglobins Campania [α1 cod95 (-C)] and Sciacca [α1 cod109 (-C)].

An insertion or deletion of a nucleotide (nt) in the penultimate or the last exon can result in a frameshift and premature termination codon (PTC), giving rise to an unstable protein variant, showing a dominant phenotype. We described two α-globin mutants created by the deletion of a nucleotide in the penultimate or the last exon of the α1-globin gene: the or α1 cod95 (-C), causing a frameshift resulting in a PTC at codon 102, and the or α1 cod109 (-C), causing a frameshift and formation of a PTC at codon 133. The carriers showed α-thalassemia alterations (mild microcytosis with normal Hb A2) and lacked hemoglobin variants.

Effect of Mutations on mRNA and Globin Stability: The Cases of Hb Bernalda/Groene Hart and Hb Southern Italy.

We identified two unstable variants in the third exon of α-globin genes: Hb Bernalda/Groene Hart (HBA1:c.358C>T), and Hb Caserta (HBA2:c.79G>A) in to Hb Sun Prairie (HBA2:c.

WTAP and BIRC3 are involved in the posttranscriptional mechanisms that impact on the expression and activity of the human lactonase PON2.

The activity of human paraoxonase 2 (PON2) is rapidly reduced in cells incubated with the bacterial quorormone 3-Oxo-dodecanoyl Homoserine Lactone (3OC12HSL), an observation that led to hypothesize a fast PON2 post-translational modification (PTM). Recently, we detected a 3OC12HSL-induced PTM in a cell-free system in which a crude extract from 3OC12HSL-treated HeLa cells was able to inactivate and ubiquitinate at position 144 a recombinant PON2. Here we show the occurrence of this and new PTMs on PON2 in HeLa cells.

Role of nonsense-mediated decay and nonsense-associated altered splicing in the mRNA pattern of two new α-thalassemia mutants.

α-thalassemia is a common disease characterized mainly by deletion mutants. We identified two new α-thalassemia pointform mutants: α1cod22 GGC>GGT Gly>Gly creating a 5' splicing sequence and α1cod23 GAG>TAG Glu>stop. We performed qualitative and semi-quantitative analysis of the mRNA molecules, from carriers' blood, to define the molecular mechanisms giving rise to the thalassemia phenotype.

Identification and molecular characterization of a novel 163 kb deletion: The Italian (ϵγδβ)(0)-thalassemia.

Objective And Importance: To verify the presence of β-thalassemia in subjects showing hematologic phenotype of α-thalassemia, conduct normal molecular sequence analysis of the α-globin genes, and detect the absence of the most frequent α-thalassemia deletions.

Clinical Presentation: A patient from Apulia (Southern Italy) was referred to our institution for the occasional founding of hypochromic polyglobulia and microcytic red blood cells associated with normal levels of Hb A2 and Hb F and normal iron parameters.

Intervention And Technique: The patient has been investigated using Sanger sequencing, multiplex ligation-dependent probe amplification (MLPA), quantitative real-time PCR, restriction analysis, and gap-PCR.

α-Thalassemia associated with hb instability: a tale of two features. the case of Hb Rogliano or α1 Cod 108(G15)Thr→Asn and Hb Policoro or α2 Cod 124(H7)Ser→Pro.

We identified two new variants in the third exon of the α-globin gene in families from southern Italy: the Hb Rogliano, α1 cod108 ACC>AAC or α1[α108(G15)Thr→Asn] and the Hb Policoro, α2 cod124 TCC>CCC or α2[α124(H7)Ser→Pro]. The carriers showed mild α-thalassemia phenotype and abnormal hemoglobin stability features. These mutations occurred in the G and H helices of the α-globin both involved in the specific recognition of AHSP and β1 chain.

Identification and molecular characterization of a novel 55-kb deletion recurrent in southern Italy: the Italian (G) γ((A) γδβ)°-thalassemia.

Objectives: To characterize the molecular basis of a β-thalassemia defect in subjects with mild microcytosis associated with normal Hb A2 and increased levels of Hb F.

Methods: Six subjects from three apparently unrelated families from Campania (southern Italy) have been investigated using DNA restriction analysis, inverse PCR, cloning, sequencing, multiplex ligation-dependent probe amplification (MLPA), quantitative real-time PCR, and gap-PCR.

Results: We have identified a novel 55-kb β-globin gene cluster deletion in three unrelated families: the Italian (G) γ((A) γδβ)°-thalassemia.

Molecular mechanisms of a novel β-thalassaemia mutation due to the duplication of tetranucleotide 'AGCT' at the junction IVS-II/exon 3.

We report a new β-thalassaemia allele detected in a young Italian woman, suffering with mild non-haemolytic anaemia (Hb < 10 g/dL) and not showing Hb variant or Heinz bodies. The allele is characterised by duplication of tetranucleotide 'AG/CT' (+1344/+1347) including the invariant dinucleotide 'AG' of IVS-II acceptor splicing site and the first two nucleotides of codon 105. β-Globin complementary DNA (cDNA) sequencing did not reveal any mutation and qualitative analysis of the reverse transcription PCR reaction showed that only the proximal 3' splice site present in the duplicated gene is used giving race to an anomalous messenger RNA (mRNA) present in trace (1.

Genotype-phenotype relationship of the δ-thalassemia and Hb A(2) variants: observation of 52 genotypes.

The increase of Hb A(2) (α2δ2) beyond the upper limit [2.0-2.2/3.

HbA2-Partinico or delta(A2)Pro-->Thr, a new genetic variation in the delta-globin gene in cis to the beta(+) thal IVS-I-110 G>A, and the heterogeneity of delta-globin alleles in double heterozygotes for beta- and delta-globin gene defects.

The study of the alleles of the delta-globin gene is relevant to the prevention of beta-thalassemia homozygosis; in fact, the increase of the HbA2 is an invaluable hematological marker of the beta-thalassemia heterozygosis and the double heterozygosis for alleles of delta- and beta-globin genes can cause the decrease of the HbA2 up to normal or borderline values. We carried out the characterization of alleles of the delta- and beta-globin genes, restriction fragment length polymorphism (RFLP) haplotype background, and hematologic phenotype in 23 double heterozygotes belonging to 18 unrelated families. A wide heterogeneity of the delta-globin alleles was detected; seven known alleles in trans to the beta-globin gene defects were revealed in 17 out of 18 families, while a new allele in cis to a beta-thalassemia allele was detected in one family.

Molecular evidences of single mutational events followed by recurrent crossing-overs in the common delta-globin alleles in the Mediterranean area.

The human delta-globin gene (HBD) is one of the beta-like globin genes expressed in adults. In the Mediterranean countries the carriers of delta-thalassemia defects or Hb A2-variants are >1% and about 40/70 known alleles have been found in families with this ethnic origin. The scope of this study was to investigate the variability of the gene and of the chromosomal background in order to highlight the origin and spreading of the delta-globin gene alleles in the Mediterranean area.

Hb Foggia or alpha 117(GH5)Phe -> Ser: a new alpha 2 globin allele affecting the alpha Hb-AHSP interaction.

We report a novel alpha2-globin gene allele with the mutation cod 117 TTC>TCC or alpha 117(GH5)Phe>Ser detected in three carriers with alpha-thalassemia phenotype. The mutated mRNA was present in the reticulocytes in the same amount as the normal one, but no chain or hemoglobin variant were detected. Most likely the amino acid substitution impairs the interaction of the alpha-chain variant with the AHSP and prevents its stabilizing effect, thus leading to the alpha-chain pool reduction.

Genotyping for known Mediterranean alpha-thalassemia point mutations using a multiplex amplification refractory mutation system.

We report the conditions of a multiplex-amplifiction refractory mutation system (ARMS) for genotyping for nine assay for the detection of alpha1 Hb J-Oxford and -alpha3.7 -AC. The method is reproducible, reliable, simple, rapid, inexpensive and provides genotype diagnosis in >70% of point-mutation carriers in Mediterranean countries.

Sequence variations of the alpha-globin genes: scanning of high CG content genes with DHPLC and DG-DGGE.

The alpha-globin chains are encoded by two duplicated genes (HBA2 and HBA1, 5'-3') showing overall sequence homology >96% and average CG content >60%. alpha-Thalassemia, the most prevalent worldwide autosomal recessive disorder, is a hereditary anemia caused by sequence variations of these genes in about 25% of carriers. We evaluated the overall sensitivity and suitability of DHPLC and DG-DGGE in scanning both the alpha-globin genes by carrying out a retrospective analysis of 19 variant alleles in 29 genotypes.

Beta-thalassaemia-87 C-->G: relationship of the Hb F modulation and polymorphisms in compound heterozygous patients.

A clinical, haematological, biochemical and molecular study was carried out in 17 patients affected with thalassaemia intermedia, who were compound heterozygotes for the beta-thalassaemia mutation beta-87 C-->G to determine the genetic basis of their clinical heterogeneity. The beta-87 was found associated with haplotype VIII (beta-87/VIII) or V (beta-87/V). The 10 patients with the beta-87/VIII showed milder clinical conditions, with significantly higher levels of haemoglobin (Hb) (9.

Hb Gun Hill: a further de novo observation.

Here we report the third observation (the second de novo) of unstable Hb Gun Hill or [b91(F7)-95(FG2)Leu-His-Cys-Asp-Lys-->0]. The two-year old male carrier showed low mean corpuscular hemoglobin (MCH) and mean hemoglobim concentration (MCHC), 8.5% fetal hemoglobin and trade mark 30% variant hemoglobin.

Beta+45 G --> C: a novel silent beta-thalassaemia mutation, the first in the Kozak sequence.

A family from the Southeast of Italy was found to have a novel beta-globin mutant, beta+45 G-->C, with the features of a silent beta-thalassaemia mutation. It was asymptomatic in two heterozygotes, but its interaction with the severe thalassaemia mutation beta-IVS-II-654 C-->T worsened the haematological and biosynthetic phenotype in two compound heterozygotes; moreover, another compound heterozygote, who was also heterozygote for the alphaalphaalpha(anti3.7), suffered from thalassaemia intermedia.

Hb Bronte or alpha93(FG5)Val-->Gly: a new unstable variant of the alpha2-globin gene, associated with a mild alpha(+)-thalassemia phenotype.

We report a new unstable variant identified in three carriers of a family from East Sicily; it was named Hb Bronte after the place from which the family originated. DNA sequencing from nucleotides -181 to +894 (alpha1) and to +884 (alpha2) revealed a GTG-->GGG substitution at codon 93 of the alpha2-globin gene. The MCV and MCH values were at the lower end of the normal range in the carriers.

Epidemiology of the delta globin alleles in southern Italy shows complex molecular, genetic, and phenotypic features.

We characterized mutations and haplotypes of the delta-globin gene (HBD, MIM# 142000) in two regions of southern Italy. Mutations were discovered by screening for individuals with Hb A2<2%. In Basilicata, about 10,000 students were screened and 53 carriers in 43 unrelated families were diagnosed; in Campania, cases were referred through a routine thalassemia counseling service.

High-level expression of hemoglobin A in human thalassemic erythroid progenitor cells following lentiviral vector delivery of an antisense snRNA.

Mutations at nucleotides 654, 705, or 745 in intron 2 of the human beta-globin gene activate aberrant 3' and 5' splice sites within the intron and prevent correct splicing of beta-globin pre-mRNA, resulting in inhibition of beta-globin synthesis and in consequence beta-thalassemia. Transfection of HeLa cells expressing the 3 thalassemic mutants with modified U7 snRNA (U7.623), containing a sequence antisense to a region between the aberrant splice sites, reduced the incorrect splicing of pre-mRNA and led to increased levels of the correctly spliced beta-globin mRNA and protein.