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1.
World J Gastrointest Oncol ; 16(5): 1705-1724, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38764833

ABSTRACT

Colorectal cancer (CRC) remains one of the most commonly diagnosed and deadliest types of cancer worldwide. CRC displays a desmoplastic reaction (DR) that has been inversely associated with poor prognosis; less DR is associated with a better prognosis. This reaction generates excessive connective tissue, in which cancer-associated fibroblasts (CAFs) are critical cells that form a part of the tumor microenvironment. CAFs are directly involved in tumorigenesis through different mechanisms. However, their role in immunosuppression in CRC is not well understood, and the precise role of signal transducers and activators of transcription (STATs) in mediating CAF activity in CRC remains unclear. Among the myriad chemical and biological factors that affect CAFs, different cytokines mediate their function by activating STAT signaling pathways. Thus, the harmful effects of CAFs in favoring tumor growth and invasion may be modulated using STAT inhibitors. Here, we analyze the impact of different STATs on CAF activity and their immunoregulatory role.

2.
Diagn Cytopathol ; 49(6): 691-699, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33600080

ABSTRACT

BACKGROUND: The Paris system (TPS) for Reporting Urinary Cytology provides a standardized reporting system whose main focus is the diagnosis of high-grade urothelial carcinoma (HGUC). We conducted a study to see the impact of The Paris System on our cytologic diagnoses with associated histology. MATERIALS AND METHODS: We reviewed our pathology database regarding urinary specimens in the year before implementation of The Paris System and the year after. We gathered the data regarding cytologic diagnosis and concurrent/subsequent histology. RESULTS: Over a 1-year period from 2016-2017, 486 urine cytology specimens were identified before implementation of The Paris System and diagnosed as follows: 83% benign/negative, 10% atypical, 2% suspicious, 5% HGUC, 0.2% low grade urothelial neoplasm (LGUN), and 0.2% unsatisfactory. Over a next 1-year period from 2017 to 2018, 602 specimens used TPS and diagnosed as follows: 85% negative for HGUC, 6% atypical, 3% suspicious, 4% HGUC, 0.17% LGUN, and 2% unsatisfactory. Although, not listed as a standardized category in The Paris System, our institution used "Negative for high-grade, cannot rule out low-grade urothelial neoplasm (NHL)" as a subcategory of Negative for HGUC. 4% of the cases fell into this category. Focusing on the Atypical category before TPS, histology was available in 15/49 (31%) cases. Of these, 40% had HGUC. Regarding the Atypical category after TPS, histology was available in 21/36 (58%) cases. Of these, 52% were HGUC. For the NHL category, concurrent histology was available in 13/26 (50%) cases. Of these, 67% were low grade urothelial neoplasms. CONCLUSION: Our study showed that TPS lowered the rate of Atypical from 10% to 6%. After the implementation of TPS, Atypical corresponded to a higher rate of high-grade urothelial carcinoma. Also, the NHL subcategory had a high positive predictive value for diagnosing low grade urothelial neoplasms.


Subject(s)
Carcinoma, Transitional Cell/diagnosis , Cytodiagnosis/methods , Cytodiagnosis/standards , Urinary Bladder Neoplasms/diagnosis , Urine/cytology , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Retrospective Studies
3.
Exp Mol Pathol ; 116: 104517, 2020 10.
Article in English | MEDLINE | ID: mdl-32791064

ABSTRACT

Primary liposarcoma of thymic stroma is an exceptionally rare tumor. Histological findings are often definitive for diagnosis, however due to the variability of nuclear atypia and the overlapping with other adipocytic tumors, ancillary techniques are helpful as confirmatory tools. Currently, Fluorescent in situ hybridization for MDM2 is the gold standard for diagnosis of well-differentiated and dedifferentiated liposarcomas, however a panel of immunohistochemical stainings, including MDM2, CDK4 and p16 is available as alternative method, helping to distinguish liposarcoma from its benign counterpart lipoma, especially in borderline cases. We describe the case of a young female diagnosed with a well-differentiated lipomatous tumor primary of thymic stroma with near cut-off result for MDM2-FISHand positive immunohistochemical staining for the panel described above. We discuss the challenges in the diagnosis of this rare entity andpresent an updated literature review.


Subject(s)
Liposarcoma/diagnosis , Proto-Oncogene Proteins c-mdm2/genetics , Thymus Neoplasms/diagnosis , Cyclin-Dependent Kinase 4/genetics , Cyclin-Dependent Kinase Inhibitor p16/genetics , Female , Humans , In Situ Hybridization, Fluorescence , Liposarcoma/genetics , Liposarcoma/pathology , Male , Middle Aged , Stromal Cells/pathology , Thymus Neoplasms/genetics , Thymus Neoplasms/pathology
4.
Hemoglobin ; 44(1): 17-19, 2020 Jan.
Article in English | MEDLINE | ID: mdl-32000548

ABSTRACT

About 10.0% of α-thalassemia (α-thal) cases are due to point mutations, small deletions, or insertions of one or more bases on the α genes that can alter mRNA processing at the transcription, translation, or post-translation level; these cases are called nondeletional α-thalassemias (α-thal). Most occur within the domain of the α2 gene without changes in the expression of the α1 gene. We present two new frameshift mutations on the HBA2 gene, associated with a nondeletional α-thal phenotype. The probands were referred to our clinic because of persistent microcytosis and hypochromia. The molecular characterization was performed by automatic sequencing of the α-globin genes. Two new mutations were detected on the HBA2 gene; HBA2: c.85delG, p.(Ala29fs*21), and HBA2: c.268_280delCACAAGCTTCGGG, p.(His90Trpfs*9). These new mutations cause a change of the reading frame, the first on codon 28 and the second from codons 89 to 93. In the first mutation, the result is an altered amino acid sequence and a premature termination codon at position 87, while the elimination of 13 bp generates a protein of 95 residues and in this case, the premature termination codon is at position 96. These types of mutation are among the most damaging changes to the coding of a protein. Not only do they lead to changes in the length of the polypeptide, but they also vary the chemical composition, which would result in a nonfunctional protein. The importance of identifying these new mutations lies in their possible association with α0-thal, which could lead to a severe thalassemia.


Subject(s)
Anemia, Hypochromic/genetics , Frameshift Mutation , Hemoglobin A2/genetics , Hemoglobin H/genetics , alpha-Globins/genetics , alpha-Thalassemia/genetics , Adult , Anemia, Hypochromic/diagnosis , Anemia, Hypochromic/pathology , Base Sequence , Codon , Female , Gene Expression , Genotype , Humans , Male , Phenotype , Sequence Analysis, DNA , Severity of Illness Index , alpha-Thalassemia/diagnosis , alpha-Thalassemia/pathology
5.
Case Rep Pathol ; 2020: 8875547, 2020.
Article in English | MEDLINE | ID: mdl-33489398

ABSTRACT

Plasmablastic lymphoma (PBL) is an aggressive high-grade B cell lymphoma, considered a variant of diffuse large B cell lymphoma with approximately 75% mortality within 6-7 months. We describe an unusual case of PBL arising as a maxillary mass in an HIV-negative, nontransplanted 78-year-old female. Histologic examination revealed a diffuse infiltrate of anaplastic appearing cells exhibiting plasmablastic morphology with an adjacent contiguous infiltrate of mature appearing plasma cells. The PBL and mature plasma cell components both demonstrated an immunophenotype of CD20(-), CD38(+), and CD138(+). The two populations differed by the PBL featuring a high proliferation rate by Ki-67 (~95%) with coexpression of both c-MYC and EBV, while the mature plasma cell component featured a low proliferation rate by Ki-67 (~5%) without coexpression of c-MYC or EBV. Kappa/lambda staining demonstrated lambda light chain restriction involving the PBL, while the mature plasma cell infiltrate revealed kappa light chain restriction. Our findings describe the rare association of PBL with a synchronous distinct population of mature plasma cells exhibiting opposite light chain restriction.

6.
Ann Hematol ; 98(7): 1537-1545, 2019 Jul.
Article in English | MEDLINE | ID: mdl-31025160

ABSTRACT

The hemoglobinopathies are a group of disorders passed down through families (inherited) in which there is abnormal production or structure of the hemoglobin molecule. They are among the most common inherited diseases around the world. Those that produce abnormal hemoglobin are called structural hemoglobinopathies while thalassemia is another type of disorder that is caused by a defect in the gene production of the globin chains. In a study ambispective comprising 1623 patients, 153 subjects showed an abnormal hemoglobin and 1470 with hypochromic and microcytic anemia, and of these 1470, 23 patients were studied for simultaneously α-thalassemias and structural hemoglobinopathies. Among the α-thalassaemia cases, 1282 cases (87.2%) were deletional α-thalassemia, 172 cases (11.7%) were non-deletional α-thalassemia, and 16 cases (1.1%) were deletional and non-deletional α-thalassamias simultaneously. Thus, approximately 12% of the cases were non-deletional α-thalassaemia. Clinical diagnosis, only 19 severe cases (1 hydrops fetalis and 18 instances of Hb H disease), 1200 thalassamias traits, and 160 thalassaemia silent carriers were recorded within the α-thalassaemia. Regarding structural hemoglobinopathies, there were only 2 cases of hemoglobinopathies with low oxygen affinity and 1 case of hemoglobin M; the remaining 150 were silent hemoglobinopathies. Non-deletional α-thalassaemia represented 12% of all α-thalassemias in our region; the most common deletion in our area was the 3.7-kb deletions, followed by Asian --(SEA) and --(FIL). The alterations responsible for non-deletional α-thalassaemia are most represented by the Hph and Hb Groene Hart and, in the case of structural hemoglobinopathies, Hb Le Lamentin and Hb J-Paris.


Subject(s)
Anemia/genetics , Base Sequence , Hemoglobins, Abnormal/genetics , Sequence Deletion , alpha-Globins/genetics , Adult , Cohort Studies , Humans , Male , Spain
7.
Clin Biochem ; 63: 139-142, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30595158

ABSTRACT

BACKGROUND: In the α-thalassemia one of the less frequent mechanisms is the nonsense mutations, which generate the substitution of a triplet that encodes an amino acid for a stop codon and, therefore, protein synthesis stops prematurely. At present, 9 mutations of this type have been documented, 6 that affect the HBA2 gene and 3 that affect the HBA1 gene. OBJECTIVES: We present a new mutation in CD16 of the HBA1 gene, where the change AAG>TAG generates a stop codon. METHODS: A 48-year-old woman from Madrid, was studied because she had maintained microcytosis without iron deficiency. Hb A2 and Hb F levels were measured by ion exchange HPLC (VARIANT II). Hemoglobin was studied by capillary zone electrophoresis and ion exchange HPLC (short program of ß-thalassemia). Molecular characterization was performed by automatic sequencing of alpha globin genes. RESULTS: The propositus presented no abnormal hemoglobins and Hb A2 and Hb F levels were within normal limits. The molecular characterization identified the new transversion mutation HBA1: c.49 A>T, which resulted in an amino acid change of Lys > Stop at codon 16 of exon 1 in the state heterozygous [α116 (A14) Lys>Stop; HBA1: c.49A>T]. CONCLUSION: In this new nonsense mutation, short genetic products may suffer nonsense-mediated degradation, whereas the abnormal protein will be eliminated through the proteolytic pathway mediated by ubiquitin. Regardless, the phenotype is mild. The most severe end of the clinical spectrum will probably occur when a mutation is inherited together with a mutation that results in suppression of two genes (-/ααT or -α/-αT).


Subject(s)
Codon, Nonsense , Codon, Terminator , Glycated Hemoglobin/genetics , alpha-Thalassemia/genetics , Female , Gene Deletion , Humans , Middle Aged , Proteolysis , Ubiquitin/metabolism
8.
Clin Chem Lab Med ; 56(2): 294-302, 2018 01 26.
Article in English | MEDLINE | ID: mdl-28796639

ABSTRACT

BACKGROUND: Thrombotic microangiopathies (TMAs) are a group of diseases that have different aetiologies and treatments, but a clinical differential diagnosis remains difficult. Among TMAs, thrombotic thrombocytopenic purpura (TTP) is characterised by a severe ADAMTS13 functional deficiency. However, assays exploring ADAMTS13 activity are limited to some specialised laboratories. Our objective was to develop and validate a diagnostic method for TTP in adult patients with TMA. METHODS: We generated a multivariable model (four predictors) on a cohort of 174 TMA patients in order to predict an ADAMTS13 activity deficiency (AUC of 0.927). The multivariable model was simplified into a binary rule to facilitate the interpretation of the predictions. There were two scenarios for a patient: (1) Predicted ADAMTS13 deficiency; if the patient met four conditions simultaneously (platelets ≤44×109/L, creatinine ≤2 mg/dL (≤176.84 µmol/L) for males or ≤1.9 mg/dL (≤168 µmol/L) for females, age ≤68 years and no history of haematopoietic stem cell transplant [HSCT]); or (2) Predicted "normal" activity; if any of the above conditions are not met. This rule was validated on a second cohort of 86 patients and performed with sensitivity of 87.7% and specificity of 92.7%. RESULTS AND CONCLUSIONS: This could lead to the earlier confirmation or rapid exclusion of TTP when ADAMTS13 testing is not avalilable, facilitating a more suitable therapy based on the aetiology of the TMA.


Subject(s)
ADAMTS13 Protein/blood , ADAMTS13 Protein/deficiency , Purpura, Thrombotic Thrombocytopenic/diagnosis , Adult , Cohort Studies , Diagnosis, Differential , Female , Humans , Male , Middle Aged , Multivariate Analysis , Purpura, Thrombotic Thrombocytopenic/physiopathology
9.
Clin Biochem ; 50(4-5): 217-222, 2017 Mar.
Article in English | MEDLINE | ID: mdl-27823958

ABSTRACT

OBJECTIVES: Hemoglobin Le Lamentin (α20(B1)His→Gln) is a ubiquitous variant that has been previously described in a small number of isolated patients. We report the incidental observation of Hb Le Lamentin in a large population from the province of Albacete, in southeastern Spain. Our study investigates possible reasons for the elevated number of carriers of this variant and its implications for the management of diabetes in our region. DESIGN & METHODS: The subjects are 32 diabetic patients whose hemoglobin displayed an unusual peak while they were being tested for glycated hemoglobin at the laboratory of the University General Hospital of Albacete over a 3-year period. Measurements were made by high performance liquid chromatography using a Variant™ II Turbo Kit-2.0, and subsequently the samples of the 32 patients with anomalous peaks were sent to the Hospital Clínico San Carlos (Madrid, Spain) for molecular characterization of any Hb variants. RESULTS: Molecular studies revealed 31 out of 32 patients heterozygous for Le Lamentin, and in one of them, Hb City of Hope was associated with Hb Le Lamentin. The remaining patient was homozygous for the Le Lamentin mutation. Additionally, most patients were native to the northeastern half of the province of Albacete and were unrelated. CONCLUSIONS: Our study describes the largest finding to date of hemoglobin Le Lamentin in a sample of patients. The fact that our region has been perpetually depopulated, with a population that has remained stable in small localities over the centuries, may have favored the survival of the mutation. Since the presence of this variant underestimates the true value of glycated hemoglobin measured by HPLC, it is necessary to systematically review chromatograms.


Subject(s)
Diabetes Mellitus/blood , Hemoglobins, Abnormal/metabolism , Adult , Aged , Aged, 80 and over , Chromatography, High Pressure Liquid , DNA Mutational Analysis , Diabetes Mellitus/genetics , Female , Glycated Hemoglobin/metabolism , Hemoglobins, Abnormal/genetics , Heterozygote , Humans , Male , Middle Aged , Spain
10.
Clin Biochem ; 49(1-2): 57-60, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26436569

ABSTRACT

OBJECTIVES: Glycated hemoglobin (HbA1c) is accepted as the most trusted marker for monitoring patients with diabetes mellitus. Ion-exchange high-performance liquid chromatography (HPLC) is one of the most widely used methods for HbA1c analysis. The presence of a hemoglobin variant can interfere with HbA1c quantification, requiring other analyses to clarify the results.Herein, we present two cases of Hb Le Lamentin, which, although they were the same variant, were thought to correspond to different hemoglobinopathies because of their percentages. DESIGN AND METHODS: Two male patients presented with an anomalous peak between HbA1c and HbA0 during a routine analysis of HbA1c using ion-exchange HPLC (Variant™ II Turbo).The hemoglobin variants were studied using capillary zone electrophoresis with the Sebia system, and the globin chains were analyzed by reverse-phase HPLC. A genetic analysis was performed using automated sequencing of the α2 and ß genes. RESULTS: In this work, we describe the first case of homozygous Hb Le Lamentin and the first double-heterozygous case of Hb Le Lamentin/Hb City of Hope. CONCLUSIONS: Although the presence of these variants does not lead to clinical anomalies, it also does not affect hematologic parameters. The variants have an impact on the determination of glycated hemoglobin levels using ion-exchange HPLC because the retention time interferes with the elution time of HbA1c, resulting in a falsely reduced value. Therefore, it is necessary to either recalculate the result or use another measurement method.


Subject(s)
Glycated Hemoglobin/analysis , Hemoglobins, Abnormal/chemistry , Chromatography, High Pressure Liquid , Chromatography, Ion Exchange , Electrophoresis, Capillary , Humans , Male , Middle Aged
12.
Clin Biochem ; 48(10-11): 662-7, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25943047

ABSTRACT

OBJECTIVES: α-thalassemias are caused by a deficiency in or absence of synthesis of the α-chain of haemoglobin (Hb). In contrast, structural haemoglobinopathies are due to mutations that change the amino acid sequence of the protein chain. We report 4 newly identified α-chain Hb variants. Two variants were hyper-unstable, whereas the other 2 were structural variants with an altered electrophoretic mobility. DESIGN AND METHODS: The first 2 families were identified because of microcytosis and hypochromia with a normal Hb A2 and Hb F but without iron deficiency. The other 2 families came to scrutiny because of a peak of abnormal Hb during routine analytical assays. These Hb variants were characterized by specific sequencing. RESULTS: The hyper-instability of Hb Cervantes is probably due to its lower affinity for the alpha chain haemoglobin-stabilizing protein (AHSP). Hb Marañón is another unstable Hb variant that produces an α-thalassemia phenotype. For the identification of Hb La Mancha, a molecular characterization by sequencing was required. Finally, Hb Goya was found to have the same electrophoretic mobility as Hb J. A lower percentage of the variant was obtained due to a possible component of instability, though the patient did not show evidence of anaemia. CONCLUSION: These variants of Hb add to the variety and complexity of disorders of the genes that encode Hb.


Subject(s)
Hemoglobinopathies/blood , Hemoglobinopathies/genetics , Hemoglobins, Abnormal/genetics , Hemoglobins, Abnormal/metabolism , Adolescent , Adult , Child, Preschool , Female , Genetic Variation/genetics , Hemoglobinopathies/diagnosis , Humans , Male , Middle Aged , Young Adult
13.
Med. clín (Ed. impr.) ; 144(5): 212-215, mar. 2015. tab, graf
Article in Spanish | IBECS | ID: ibc-132741

ABSTRACT

Fundamento y objetivo: Las talasemias son las enfermedades monogénicas más frecuentes a nivel mundial. Representan un grave problema sanitario en las regiones de mayor incidencia. Las α-talasemias se deben a un déficit de síntesis de las cadenas α de la hemoglobina (Hb). La Hb Groene Hart es una variante hiperinestable. En este trabajo se presentan 24 casos pertenecientes a 17 familias afectadas por la Hb Groene Hart, uno de ellos asociado con Hb J-París-I. Pacientes y método: Veinticuatro pacientes de 17 familias no relacionadas fueron incluidos en este estudio. La caracterización se realizó mediante secuenciación. Resultados: La secuenciación del gen α1 mostró la mutación CCT→TCT (Pro→Ser) en el codón 119 (Hb Groene Hart). En un paciente se asoció con la Hb J-París-I. Conclusiones: En la Hb Groene Hart se encuentra afectado un residuo clave para preservar la estabilidad de las cadenas α de globina. La presencia de esta variante es elevada en población española e inmigrante. La aparición de formas graves de la enfermedad podría ser evitada incorporando esta mutación al cribado de las mutaciones α-talasemia no deleción (AU)


Background and objective: Thalassemias are the most frequent monogenic disorder around the world. α-thalassemias are due to a deficiency of synthesis in the alpha-globin chain of the hemoglobin (Hb). Hb Groene Hart is a hyperunstable variant. In this work, we have studied 24 cases affected by Hb Groene Hart, one of them associated with Hb J-Paris-I. Patients and methods: Twenty-four patients from 17 unrelated families were included in this study. The characterization was done by sequencing. Results: α1 gene sequencing showed the mutation CCT→TCT (Pro→Ser) at codon 119 (Hb Groene Hart) in all patients. In one case, there was an association with Hb J-Paris-I. Conclusions: In the Hb Groene Hart, the residue 119 of alpha-globin chain is affected. This amino acid has a key role in preserving the stability of alpha-globin chain. It is also remarkable the presence of this variant in both the immigrant and native population. Thus, the identification of Hb Groene Hart carriers should be considered in the screening of α-thalassemia in Spain, as it is done in Northern Africa (AU)


Subject(s)
Humans , Male , Female , Adult , Child , Middle Aged , Hemoglobin J/genetics , Hemoglobins, Abnormal/genetics , alpha-Globins/genetics , alpha-Thalassemia/genetics , Genetic Markers , Heterozygote , Mutation , Spain
14.
Med Clin (Barc) ; 144(5): 212-5, 2015 Mar 09.
Article in Spanish | MEDLINE | ID: mdl-24530052

ABSTRACT

BACKGROUND AND OBJECTIVE: Thalassemias are the most frequent monogenic disorder around the world. α-thalassemias are due to a deficiency of synthesis in the alpha-globin chain of the hemoglobin (Hb). Hb Groene Hart is a hyperunstable variant. In this work, we have studied 24 cases affected by Hb Groene Hart, one of them associated with Hb J-Paris-I. PATIENTS AND METHODS: Twenty-four patients from 17 unrelated families were included in this study. The characterization was done by sequencing. RESULTS: α1 gene sequencing showed the mutation CCT→TCT (Pro→Ser) at codon 119 (Hb Groene Hart) in all patients. In one case, there was an association with Hb J-Paris-I. CONCLUSIONS: In the Hb Groene Hart, the residue 119 of alpha-globin chain is affected. This amino acid has a key role in preserving the stability of alpha-globin chain. It is also remarkable the presence of this variant in both the immigrant and native population. Thus, the identification of Hb Groene Hart carriers should be considered in the screening of α-thalassemia in Spain, as it is done in Northern Africa.


Subject(s)
Hemoglobin J/genetics , Hemoglobins, Abnormal/genetics , alpha-Globins/genetics , alpha-Thalassemia/genetics , Adolescent , Adult , Child , Child, Preschool , Female , Genetic Markers , Heterozygote , Humans , Male , Middle Aged , Mutation , Spain
15.
Int J Hematol ; 100(6): 599-601, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25212678

ABSTRACT

Thalassemias are the most frequent monogenic disorders around the world and are a serious health problem in areas with a high incidence. Thalassemias are particularly frequent in Mediterranean countries, the Middle East, Africa, the Indian subcontinent, and in the Southeast Asia. Of these, α-thalassemia is inherited as an autosomal recessive disorder. α-thalassemias are due to a deficiency or absence of hemoglobin (Hb) α-chain synthesis and are characterized by microcytic and hypochromic cells anemia and a clinical phenotype varying from nearly asymptomatic to a lethal hemolytic anemia. Compound heterozygotes and some homozygotes have a moderate to severe form of α-thalassemia called HbH disease. Hb Bart's hydrops fetalis is a lethal form in which no α-globin chain is synthesized. In this study we show a new structural variant of α-chain, Hb Cibeles [alpha 25(B6) Gly → Asp], in heterozygous state, which was undetectable by electrophoretic or chromatographic methods. Hb Cibeles is thus a hyper-unstable hemoglobinopathy. In this new globin chain variant, an apolar amino acid is replaced by a negatively charged amino acid. This change may be responsible for the molecular hyper-instability similar to the mutation in the adjacent residues.


Subject(s)
Genetic Variation , Hemoglobins, Abnormal/genetics , alpha-Globins/genetics , alpha-Thalassemia/genetics , Child, Preschool , DNA Mutational Analysis , Heterozygote , Humans , Male , Mutation , alpha-Thalassemia/diagnosis
16.
J Hum Genet ; 59(10): 585-7, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25186056

ABSTRACT

The locus control region (LCR) is a genetic region that regulates the expression of the ß-globin locus (HBB locus). This region is composed of several DNase I hypersensitive sites (HSs) in which the regulatory functions of the LCR may reside. To date, some individuals bearing deletions of several HSs or even the complete LCR have been described. Although the globin genes of the HBB locus are intact, most of these patients suffer thalassemia due to the reduced expression of such genes. The LCR and the HSs forming it have been thoroughly studied in different genetic models. However, seemingly contradictory results are often obtained. Here, we describe the first deletion found in humans exclusively affecting the HS3 element of the LCR. The adult carrying this deletion shows very mild hematological modifications, indicating that HS3 deletion does not severely impair the ß-gene expression. Our results also reveal limitations of the murine models when studying the native mouse genes for understanding human diseases like thalassemias.


Subject(s)
Locus Control Region/genetics , Sequence Deletion , beta-Globins/genetics , beta-Thalassemia/genetics , Adult , Base Sequence , Erythrocytes/metabolism , Heterozygote , Humans , Male , Multigene Family/genetics , Phenotype
17.
Hemoglobin ; 37(2): 112-8, 2013.
Article in English | MEDLINE | ID: mdl-23425204

ABSTRACT

In the 5' untranslated region (5'UTR), which is transcribed but not translated and is involved in posttranscriptional regulation of the gene promoting and stabilizing the mRNA translation, several mutations associated with mild ß-thalassemia (ß-thal) have been described. One of these, the +20 (C>T) mutation, is described in the HbVar database as a mutation responsible for ß(+)-thal. In heterozygote cases, it gives rise to a phenotype of ß-thal minor and ß-thal intermediate (ß-TI) when the mutation is associated with ß(+) IVS-II-745 (C>G). To clarify if this mutation is responsible for ß(+)-thal, we studied nine cases where we found an association of the +20 and IVS-II-745 mutations. All patients were carriers of four α genes. Three patients carried ß-thal major (ß-TM), two were compound heterozygotes for IVS-II-745 and codon 8 (-AA) or codon 39 (C>T), and the third was homozygous for IVS-II-745; all had the +20 mutation in the 5'UTR. The remaining patients showed the mutation IVS-II-745 associated with a replacement of C>T at nucleotide (nt) +20 of the 5'UTR. Contrary to reports in the HbVar database, the +20 mutation should be considered as an innocuous single nt polymorphism associated with the IVS-II-745 mutation in cis.


Subject(s)
5' Untranslated Regions/genetics , Introns/genetics , Point Mutation , beta-Globins/genetics , beta-Thalassemia/genetics , Adult , Child, Preschool , DNA Mutational Analysis , Family Health , Female , Humans , Male , Middle Aged , Pedigree , Polymorphism, Single Nucleotide , Young Adult , beta-Thalassemia/diagnosis
18.
Hemoglobin ; 37(1): 48-55, 2013.
Article in English | MEDLINE | ID: mdl-23215953

ABSTRACT

We report a rare association of δß-thalassemia (δß-thal) and a hemoglobin (Hb) variant with high oxygen affinity in a Spanish newborn. The proband had no Hb A and showed microcytosis and hypochromia; the peripheral blood smear was compatible with a thalassemia trait. Molecular studies revealed that the proband had a Spanish (δß)(0)-thal (inherited from his father) and also carried a de novo variant (Hb Andrew-Minneapolis) because from the point of hematology, his mother was quite normal. The hemoglobinopathies with high affinity for oxygen constitute an infrequent cause of secondary congenital erythrocytosis. The degree of erythrocytosis and the resulting clinical manifestations are highly variable, depending on the degree of altered oxygen affinity and the presence of thalassemic genes. Thus, when these variants are associated with ß(0)- or δß-thal, as in our case, the proportion of abnormal Hb is ∼100.0%, which may cause polycythemia, hyperviscosity, and iron deficiency. This type of association is very rare and few have been described, especially in children, as they would normally be detected in adults as the increased packed cell volume (PCV) also increases blood viscosity and causes the typical symptoms (cephalalgia, drowsiness, dizziness). The association of a high oxygen affinity Hb and a δß-thal presents a greater degree of erythrocytosis than when this same variant is associated with a ß(0)-thal, mainly because the Hb F percentage is usually greater in the δß-thal, and Hb F normally shows a greater affinity for oxygen and a reduced P(50), although one must always take into account the degree of oxygen affinity of the Hb variant. Familial erythrocytosis and an abnormal electrophoresis finding are indicative of a high affinity Hb. However, the absence of these findings does not reject the possibility of hemoglobinopathies, and in these cases, functional and molecular studies would be justified and should be mandatory for the differential diagnosis of erythrocytosis.


Subject(s)
Hemoglobins, Abnormal/metabolism , Polycythemia/complications , beta-Thalassemia/complications , delta-Thalassemia/complications , Hemoglobins, Abnormal/genetics , Humans , Infant, Newborn , Oxygen/metabolism , Polycythemia/blood , Polycythemia/genetics , beta-Thalassemia/blood , beta-Thalassemia/genetics , delta-Thalassemia/blood , delta-Thalassemia/genetics
19.
Hemoglobin ; 36(6): 526-32, 2012.
Article in English | MEDLINE | ID: mdl-23094635

ABSTRACT

Most α-thalassemia (α-thal) mechanisms are deletions of one or both α-globin genes and less than 5.0-10.0% are point mutations. Hb Agrinio [α29(B10)Leu→Pro, CTG>CCG (α2)] is a hyperunstable α chain structural variant in which the thalassemic phenotype is determined by a post translational precipitation of the structurally anomalous chain in erythroid precursors. This study involved 14 cases with Hb Agrinio from three families. Selective sequencing of the α2 gene showed a CTG(Leu)>CCG(Pro) mutation at codon 29. The mutation was found in a heterozygous state in 11 cases and in a homozygous state in three cases. These are the first cases with Hb Agrinio described in Spain. In all cases where a leucine is exchanged for a proline, an unstable hemoglobin (Hb) will occur both in the α and the ß chain. Some of these are as unstable as Hb Agrinio and their presence is difficult to detect except by DNA sequencing.


Subject(s)
Amino Acid Substitution , Codon , Hemoglobins, Abnormal/genetics , Mutation , White People/genetics , Adolescent , Adult , Alleles , Base Sequence , Child , Child, Preschool , Family , Female , Genotype , Homozygote , Humans , Male , Middle Aged , Spain , Young Adult , alpha-Thalassemia/diagnosis , alpha-Thalassemia/genetics
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