TET2 missense variants in human neoplasia. A proposal of structural and functional classification

The human TET2 gene plays a pivotal role in the epigenetic regulation of normal and malignant hematopoiesis. Somatic TET2 mutations have been repeatedly identified in age-related clonal hematopoiesis and in myeloid neoplasms ranging from acute myeloid leukemia (AML) to myeloproliferative neoplasms. However, there have been no attempts to systematically explore the structural and functional consequences of the hundreds of TET2 missense variants reported to date. We have sequenced the TET2 gene in 189 Spanish AML patients using Sanger sequencing and NGS protocols. Next, we performed a thorough bioinformatics analysis of TET2 protein and of the expected impact of all reported TET2 missense variants on protein structure and function, exploiting available structure-and-function information as well as 3D structure prediction tools. We have identified 38 TET2 allelic variants in the studied patients, including two frequent SNPs: p.G355D (10 cases) and p.I1762V (28 cases). Four of the detected mutations are reported here for the first time: c.122C>T (p.P41L), c.4535C>G (p.A1512G), c.4760A>G (p.D1587G), and c.5087A>T (p.Y1696F). We predict a complex multidomain architecture for the noncatalytic regions of TET2, and in particular the presence of well-conserved α+β globular domains immediately preceding and following the actual catalytic unit. Further, we provide a rigorous interpretation of over 430 missense SNVs that affect the TET2 catalytic domain, and we hypothesize explanations for ~700 additional variants found within the regulatory regions of the protein. Finally, we propose a systematic classification of all missense mutants and SNPs reported to date into three major categories (severe, moderate, and mild), based on their predicted structural and functional impact. The proposed classification of missense TET2 variants would help to assess their clinical impact on human neoplasia and may guide future structure-and-function investigations of TET family members

Many signs, one mutation : Early onset of de novo GATA2 deficiency syndrome. A case report

We report a case with a broad spectrum of symptoms, related to GATA2 deficiency syndrome, which emerged as early as at 6 months of age. They ranged from lymphedema, deafness to myelodysplastic syndrome (MDS). Non-hematologic symptoms may long precede myelodysplastic syndrome diagnosis in patients with GATA2 mutations

Bone marrow fibrosis, sequence variant of asxl1, and Sjögren syndrome : A case report

Only proven pathogenic mutations associated with myeloid neoplasms are key to establish the clonal nature of the bone marrow fibrosis. In cases with genetic variants of uncertain meaning, the clinical picture may be required to rule out secondary causes. Only proven pathogenic mutations associated with myeloid neoplasms are key to establish the clonal nature of the bone marrow fibrosis. In cases with genetic variants of uncertain meaning, the clinical picture may be required to rule out secondary causes

Bone Marrow WT1 Levels in Allogeneic Hematopoietic Stem Cell Transplantation for Acute Myelogenous Leukemia and Myelodysplasia : Clinically Relevant Time Points and 100 Copies Threshold Value

The outcome of allogeneic hematopoietic stem cell transplantation (HCT) in patients with myeloid malignancies is better in those without minimal residual disease (MRD) than in those with MRD+, as assessed by multiparametric flow cytometry (MPFC). WT1 quantitation also has been used to assess the probability of relapse in acute myelogenous leukemia (AML) treated with chemotherapy. We analyzed the clinical value of normalized bone marrow WT1 levels as a measure of the expanded myeloid progenitor compartment in a consecutive series of 193 adult patients with myeloid malignancies who underwent HCT. Bone marrow WT1 levels before the HCT, at the first bone marrow aspirate after infusion, and in the follow-up samples after HCT were determined by means of real-time PCR using the European LeukemiaNet normalized method. We sought to clarify the prognostic relevance in terms of overall survival (OS), progression-free survival (PFS), and cumulative incidence of relapse (CIR). Based on earlier experience in AML, we selected a threshold of 100 copies, defining 2 groups: patients with 100 copies also included patients who were negative for MRD as assessed by MPFC (19 of 32). During the HCT follow-up, patients with sustained WT1 levels 100 copies (mean, 68 ± 11 versus 26 ± 7 days, P <.001; 63 ± 11 versus 20 ± 8 days, P <.001; and 20 ± 8 vs. 71 ± 8 days, P <.001, respectively). Standardized bone marrow WT1 levels using a 100-copy threshold in samples obtained before HCT, at leukocyte recovery, and during follow-up provided relevant prognostic information in patients with myeloid malignacies submitted to HCT

Bone marrow fibrosis, sequence variant of asxl1, and Sjögren syndrome : A case report

Only proven pathogenic mutations associated with myeloid neoplasms are key to establish the clonal nature of the bone marrow fibrosis. In cases with genetic variants of uncertain meaning, the clinical picture may be required to rule out secondary causes. Only proven pathogenic mutations associated with myeloid neoplasms are key to establish the clonal nature of the bone marrow fibrosis. In cases with genetic variants of uncertain meaning, the clinical picture may be required to rule out secondary causes

Many signs, one mutation : Early onset of de novo GATA2 deficiency syndrome. A case report

We report a case with a broad spectrum of symptoms, related to GATA2 deficiency syndrome, which emerged as early as at 6 months of age. They ranged from lymphedema, deafness to myelodysplastic syndrome (MDS). Non-hematologic symptoms may long precede myelodysplastic syndrome diagnosis in patients with GATA2 mutations

A New Locus for Autosomal Recessive Retinitis Pigmentosa (RP19) Maps to 1p13–1p21

16 páginas, 2 figuras, 2 tablas.Autosomal recessive retinitis pigmentosa (arRP) is characterized by considerable allelic and nonallelic heterogeneity. Mutations have been described in the rhodopsin gene (RHO), the genes encoding the α and β subunits of rod phosphodiesterase (PDEA and PDEB), and the gene encoding the α subunit of the cGMP-gated channel (CNCG). In addition, linkage studies in single extended pedigrees have defined two new arRP loci, at 1q and 6p. To identify the disease gene in a Spanish consanguineous arRP family, a linkage analysis was undertaken. After testing 102 polymorphic markers, a significant positive lod score (Zmax= 3.64 at θ = 0) was obtained with marker D1S188 at 1p13–p21, the same region where the Stargardt and fundus flavimaculatus (FFM) loci were previously defined. Exhaustive ophthalmologic examination of the patients clearly distinguished the disease from the Stargardt and FFM phenotypes and revealed an atypical form of arRP with choroidal atrophy as a distinctive feature.This work was supported by Spanish CICYT (SAF93-0479-062-01; SAF96-0329) and the Federación de Asociaciones de Afectados de Retinosis Pigmentaria del Estado Español (FAARPE). A. Martínez Mir y M. Bayés are recipients of a fellowship from the Generalitat de Catalunya.Peer reviewe

Diagnostic distribution of self-disorders in help-seeking adolescents: an early faeature of the schizophrenia spectrum

Self-disorders (SD) have been considered as a core feature of schizophrenia in both classical and recent psychopathological literature. However, the specificity of SD to the schizophrenia spectrum has mainly been tested in adult samples, with studies in adolescents being scarce. Thus, the aims of this study were: 1) to examine the specificity of SD to the schizophrenia spectrum in a help-seeking adolescent sample; 2) to explore the correlations between SD and social and role functioning. One hundred 13-18-year-old inpatients underwent a comprehensive psychopathological examination. SD were assessed using the Examination of Anomalous Self-Experiences (EASE), and social and role functioning were assessed using the Global Functioning: Social (GF:S) and Role (GF:R) scales. The diagnostic distribution of the EASE scores was tested using Mann–Whitney U test, the correlations between the EASE scores and the GF:S and GF:R scores were tested using Spearman's ρ. EASE scores were significantly higher in schizophrenia spectrum disorders than in other spectrum disorders, whereas in schizophrenia spectrum psychoses and schizotypal personalities did not differ. Furthermore, higher EASE scores significantly correlated with lower GF:S and GF:R scores. This findings confirm the validity of SD as an experiential vulnerability phenotype of the schizophrenia spectrum, even in adolescents

Immunohistochemical analysis of PTEN in endometrial carcinoma: a tissue microarray study with a comparison of four commercial antibodies in correlation with molecular abnormalities

The tumor suppressor gene PTEN/MMAC1 is located on chromosome 10q23.3. Inactivation of PTEN, either by mutations, deletions, or promoter hypermethylation, has been identified in a wide variety of tumors. Inactivation of the two alleles of PTEN is required, because it is a tumor suppressor gene. Immunohistochemical staining may be an effective screening method to demonstrate the absence of the protein in tumors exhibiting PTEN inactivation. We studied a tissue microarray, constructed from paraffin-embedded blocks of 95 endometrial carcinomas, 38 of them previously evaluated for alterations in PTEN. We also studied cell blocks obtained from one PTEN-defective endometrial cancer cell line, after transfection with either a plasmid encoding wild-type PTEN or the empty vector. The tumor samples were tested with four different anti-PTEN commercial antibodies: a polyclonal antibody, the monoclonal antibody 28H6, the monoclonal antibody 10P03, and the monoclonal antibody 6.H2.1. Results were correlated with the presence of abnormalities in PTEN, as well as with the immunohistochemical expression of phosphorylated AKT. Antibody 28H6 produced a predominant nuclear staining, while the other three antibodies produced a predominant cytoplasmic staining. There was no significant correlation between the results obtained with the four antibodies. The monoclonal antibody 6.H2.1 was the only one that exhibited a correlation with the presence of molecular alterations in PTEN, and a statistically significant association with immunostaining for phosphorylated AKT (r ¼ 0.249, P ¼ 0.037). The monoclonal antibody 10P03 exhibited an association with phospho-AKT that did not have statistical significance. Both 6.H2.1 and 10P03 antibodies stained PTEN-transfected cells, and were negative in the PTEN-deficient cell line blocks. The polyclonal antibody and the monoclonal antibody 28H6 produced positive staining in PTEN-deficient cell line blocks, suggesting nonspecific staining. The results indicate that monoclonal antibody 6.H2.1 may be a suitable alternative for tumors with inactivation of PTEN

A new autosomal recessive retinitis pigmentosa locus maps on chromosome 2q31-q33

5 páginas, 2 tablas, 2 figuras.Autosomal recessive retinitis pigmentosa (ARRP) is a genetically heterogeneous disease. To date, mutations in four members of the phototransduction cascade have been implicated in ARRP. Additionally, linkage of the disease to three loci on 1p, 1q, and 6p has been described. However, the majority of cases are still uncharacterised. We have performed linkage analysis in a large nuclear ARRP family with five affected sibs. After exclusion of several regions of the genome known to contain loci for retinal dystrophies, a genomic search for linkage to ARRP was undertaken. Positive lod scores were obtained with markers on 2q31-q33 (Zmax at theta = 0.00 of 4.03, 4.12, and 4.12 at D2S364, D2S118, and D2S389, respectively) defining an interval of about 7 cM for this new ARRP locus, between D2S148 and D2S161. Forty-four out of 47 additional ARRP families, tested with markers on 2q32, failed to show linkage, providing evidence of further genetic heterogeneity.This work was supported by Spanish CICYT (SAF93-0479-062-01 and SAF96-0329) and the "Federaci6n de Asociaciones de Afectados de Retinosis Pigmentaria del Estado Español" (FAARPE). A Martinez-Mir and M Bayes are recipients of a fellowship from the Generalitat de Catalunya.Peer reviewe