TY - JOUR T1 - Loss-of-function mutations in cause a new form of inherited thrombocytopenia. JF - Blood Y1 - 2019 A1 - Marconi, Caterina A1 - Di Buduo, Christian A A1 - LeVine, Kellie A1 - Barozzi, Serena A1 - Faleschini, Michela A1 - Bozzi, Valeria A1 - Palombo, Flavia A1 - McKinstry, Spencer A1 - Lassandro, Giuseppe A1 - Giordano, Paola A1 - Noris, Patrizia A1 - Balduini, Carlo L A1 - Savoia, Anna A1 - Balduini, Alessandra A1 - Pippucci, Tommaso A1 - Seri, Marco A1 - Katsanis, Nicholas A1 - Pecci, Alessandro AB -

Inherited thrombocytopenias (ITs) are a heterogeneous group of disorders characterized by low platelet count that may result in bleeding tendency. Despite progress being made in defining the genetic causes of ITs, nearly 50% of patients with familial thrombocytopenia are affected with forms of unknown origin. Here, through exome sequencing of 2 siblings with autosomal-recessive thrombocytopenia, we identified biallelic loss-of-function variants in This gene encodes for a receptor-like PTP, PTPRJ (or CD148), which is expressed abundantly in platelets and megakaryocytes. Consistent with the predicted effects of the variants, both probands have an almost complete loss of PTPRJ at the messenger RNA and protein levels. To investigate the pathogenic role of PTPRJ deficiency in hematopoiesis in vivo, we carried out CRISPR/Cas9-mediated ablation of (the ortholog of human ) in zebrafish, which induced a significantly decreased number of CD41 thrombocytes in vivo. Moreover, megakaryocytes of our patients showed impaired maturation and profound defects in SDF1-driven migration and formation of proplatelets in vitro. Silencing of in a human megakaryocytic cell line reproduced the functional defects observed in patients' megakaryocytes. The disorder caused by mutations presented as a nonsyndromic thrombocytopenia characterized by spontaneous bleeding, small-sized platelets, and impaired platelet responses to the GPVI agonists collagen and convulxin. These platelet functional defects could be attributed to reduced activation of Src family kinases. Taken together, our data identify a new form of IT and highlight a hitherto unknown fundamental role for PTPRJ in platelet biogenesis.

VL - 133 IS - 12 U1 - http://www.ncbi.nlm.nih.gov/pubmed/30591527?dopt=Abstract ER - TY - JOUR T1 - ACTN1 mutations lead to a benign form of platelet macrocytosis not always associated with thrombocytopenia. JF - Br J Haematol Y1 - 2018 A1 - Faleschini, Michela A1 - Melazzini, Federica A1 - Marconi, Caterina A1 - Giangregorio, Tania A1 - Pippucci, Tommaso A1 - Cigalini, Elena A1 - Pecci, Alessandro A1 - Bottega, Roberta A1 - Ramenghi, Ugo A1 - Siitonen, Timo A1 - Seri, Marco A1 - Pastore, Annalisa A1 - Savoia, Anna A1 - Noris, Patrizia AB -

The inherited thrombocytopenias (IT) are a heterogeneous group of diseases resulting from mutations in more than 30 different genes. Among them, ACTN1-related thrombocytopenia (ACTN1-RT; Online Mendelian Inheritance in Man: 615193) is one of the most recently identified forms. It has been described as a mild autosomal dominant macrothrombocytopenia caused by mutations in ACTN1, a gene encoding for one of the two non-muscle isoforms of α-actinin. We recently identified seven new unrelated families with ACTN1-RT caused by different mutations. Two of them are novel missense variants (p.Trp128Cys and p.Pro233Leu), whose pathogenic role has been confirmed by in vitro studies. Together with the 10 families we have previously described, our cohort of ACTN1-RT now consists of 49 individuals carrying ACTN1 mutations. This is the largest case series ever collected and enabled a critical evaluation of the clinical aspects of the disease. We concluded that ACTN1-RT is the fourth most frequent form of IT worldwide and it is characterized by platelet macrocytosis in all affected subjects and mild thrombocytopenia in less than 80% of cases. The risk of bleeding, either spontaneous or upon haemostatic challenge, is negligible and there are no other associated defects, either congenital or acquired. Therefore, ACTN1-RT is a benign form of IT, whose diagnosis provides affected individuals and their families with a good prognosis.

VL - 183 IS - 2 U1 - http://www.ncbi.nlm.nih.gov/pubmed/30351444?dopt=Abstract ER - TY - JOUR T1 - A new form of inherited thrombocytopenia due to monoallelic loss of function mutation in the thrombopoietin gene. JF - Br J Haematol Y1 - 2018 A1 - Noris, Patrizia A1 - Marconi, Caterina A1 - De Rocco, Daniela A1 - Melazzini, Federica A1 - Pippucci, Tommaso A1 - Loffredo, Giuseppe A1 - Giangregorio, Tania A1 - Pecci, Alessandro A1 - Seri, Marco A1 - Savoia, Anna VL - 181 IS - 5 U1 - http://www.ncbi.nlm.nih.gov/pubmed/28466964?dopt=Abstract ER - TY - JOUR T1 - Mutations of RUNX1 in families with inherited thrombocytopenia. JF - Am J Hematol Y1 - 2017 A1 - De Rocco, Daniela A1 - Melazzini, Federica A1 - Marconi, Caterina A1 - Pecci, Alessandro A1 - Bottega, Roberta A1 - Gnan, Chiara A1 - Palombo, Flavia A1 - Giordano, Paola A1 - Coccioli, Maria Susanna A1 - Glembotsky, Ana C A1 - Heller, Paula G A1 - Seri, Marco A1 - Savoia, Anna A1 - Noris, Patrizia KW - Adult KW - Blood Platelets KW - Cell Size KW - Child KW - Child, Preschool KW - Core Binding Factor Alpha 2 Subunit KW - Female KW - Frameshift Mutation KW - Genes, Dominant KW - Heterozygote KW - Humans KW - Introns KW - Leukemia, Myeloid, Acute KW - Male KW - Middle Aged KW - Mutation, Missense KW - Protein Domains KW - RNA Splice Sites KW - Sequence Deletion KW - Thrombocythemia, Essential KW - Thrombopoietin KW - Transcriptional Activation KW - Young Adult VL - 92 IS - 6 U1 - http://www.ncbi.nlm.nih.gov/pubmed/28240786?dopt=Abstract ER - TY - JOUR T1 - Clinical and pathogenetic features of ETV6 related thrombocytopenia with predisposition to acute lymphoblastic leukemia. JF - Haematologica Y1 - 2016 A1 - Melazzini, Federica A1 - Palombo, Flavia A1 - Balduini, Alessandra A1 - De Rocco, Daniela A1 - Marconi, Caterina A1 - Noris, Patrizia A1 - Gnan, Chiara A1 - Pippucci, Tommaso A1 - Bozzi, Valeria A1 - Faleschini, Michela A1 - Barozzi, Serena A1 - Doubek, Michael A1 - Di Buduo, Christian A A1 - Stano Kozubik, Katerina A1 - Radova, Lenka A1 - Loffredo, Giuseppe A1 - Pospisilova, Sarka A1 - Alfano, Caterina A1 - Seri, Marco A1 - Balduini, Carlo L A1 - Pecci, Alessandro A1 - Savoia, Anna AB -

ETV6-related thrombocytopenia (ETV6-RT) is an autosomal dominant thrombocytopenia that has been recently identified in a few families and has been suspected to predispose to hematological malignancies. To gain further information on this disorder, we searched for ETV6 mutations in the 130 families with inherited thrombocytopenia of unknown origin from our cohort of 274 consecutive pedigrees with familial thrombocytopenia. We identified 20 ETV6-RT patients from 7 pedigrees. They have 5 different ETV6 variants, including three novel mutations affecting the highly conserved E26 transformation-specific domain. The relative frequency of ETV6-RT resulted 2.6% in the whole case series and 4.6% among the families with known forms of inherited thrombocytopenia. The degree of thrombocytopenia and bleeding tendency of ETV6-RT patients were mild, but 4 subjects developed B-cell acute lymphoblastic leukemia during childhood, resulting in a significantly increased incidence compared to the general population. Clinical and laboratory findings did not identify any peculiar defects that can be used to suspect this disorder by routine diagnostic workup. However, at variance with most inherited thrombocytopenias, platelet size was not enlarged. In vitro studies revealed that patients megakaryocytes have defective maturation and impaired proplatelet formation. Moreover, ETV6-RT platelets have reduced ability to spread on fibrinogen. Since also the dominant thrombocytopenias due to mutations in RUNX1 and ANKRD26 are characterized by normal platelet size and predispose to hematological malignancies, we suggest that mutation screening of ETV6, RUNX1 and ANKRD26 should be performed in all the subjects with autosomal dominant thrombocytopenia and normal platelet size.

U1 - http://www.ncbi.nlm.nih.gov/pubmed/27365488?dopt=Abstract ER - TY - JOUR T1 - ACTN1-related thrombocytopenia: identification of novel families for phenotypic characterization. JF - Blood Y1 - 2015 A1 - Bottega, Roberta A1 - Marconi, Caterina A1 - Faleschini, Michela A1 - Baj, Gabriele A1 - Cagioni, Claudia A1 - Pecci, Alessandro A1 - Pippucci, Tommaso A1 - Ramenghi, Ugo A1 - Pardini, Simonetta A1 - Ngu, Loretta A1 - Baronci, Carlo A1 - Kunishima, Shinji A1 - Balduini, Carlo L A1 - Seri, Marco A1 - Savoia, Anna A1 - Noris, Patrizia KW - Actinin KW - Adolescent KW - Adult KW - Aged KW - Aged, 80 and over KW - Blood Platelets KW - Case-Control Studies KW - Child KW - Child, Preschool KW - Female KW - Gene Expression KW - Genotype KW - Heterozygote KW - Humans KW - Male KW - Middle Aged KW - Mutation, Missense KW - Pedigree KW - Phenotype KW - Platelet Count KW - Severity of Illness Index KW - Thrombocytopenia KW - Thrombopoiesis KW - Thrombopoietin AB -

Inherited thrombocytopenias (ITs) are a heterogeneous group of syndromic and nonsyndromic diseases caused by mutations affecting different genes. Alterations of ACTN1, the gene encoding for α-actinin 1, have recently been identified in a few families as being responsible for a mild form of IT (ACTN1-related thrombocytopenia; ACTN1-RT). To better characterize this disease, we screened ACTN1 in 128 probands and found 10 (8 novel) missense heterozygous variants in 11 families. Combining bioinformatics, segregation, and functional studies, we demonstrated that all but 1 amino acid substitution had deleterious effects. The clinical and laboratory findings of 31 affected individuals confirmed that ACTN1-RT is a mild macrothrombocytopenia with low risk for bleeding. Low reticulated platelet counts and only slightly increased serum thrombopoietin levels indicated that the latest phases of megakaryopoiesis were affected. Given its relatively high frequency in our cohort (4.2%), ACTN1-RT has to be taken into consideration in the differential diagnosis of ITs.

VL - 125 IS - 5 U1 - http://www.ncbi.nlm.nih.gov/pubmed/25361813?dopt=Abstract ER - TY - JOUR T1 - Analysis of 339 pregnancies in 181 women with 13 different forms of inherited thrombocytopenia. JF - Haematologica Y1 - 2014 A1 - Noris, Patrizia A1 - Schlegel, Nicole A1 - Klersy, Catherine A1 - Heller, Paula G A1 - Civaschi, Elisa A1 - Pujol-Moix, Núria A1 - Fabris, Fabrizio A1 - Favier, Rémi A1 - Gresele, Paolo A1 - Latger-Cannard, Véronique A1 - Cuker, Adam A1 - Nurden, Paquita A1 - Greinacher, Andreas A1 - Cattaneo, Marco A1 - De Candia, Erica A1 - Pecci, Alessandro A1 - Hurtaud-Roux, Marie-Françoise A1 - Glembotsky, Ana C A1 - Muñiz-Diaz, Eduardo A1 - Randi, Maria Luigia A1 - Trillot, Nathalie A1 - Bury, Loredana A1 - Lecompte, Thomas A1 - Marconi, Caterina A1 - Savoia, Anna A1 - Balduini, Carlo L A1 - Bayart, Sophie A1 - Bauters, Anne A1 - Benabdallah-Guedira, Schéhérazade A1 - Boehlen, Françoise A1 - Borg, Jeanne-Yvonne A1 - Bottega, Roberta A1 - Bussel, James A1 - De Rocco, Daniela A1 - de Maistre, Emmanuel A1 - Faleschini, Michela A1 - Falcinelli, Emanuela A1 - Ferrari, Silvia A1 - Ferster, Alina A1 - Fierro, Tiziana A1 - Fleury, Dominique A1 - Fontana, Pierre A1 - James, Chloé A1 - Lanza, Francois A1 - Le Cam Duchez, Véronique A1 - Loffredo, Giuseppe A1 - Magini, Pamela A1 - Martin-Coignard, Dominique A1 - Menard, Fanny A1 - Mercier, Sandra A1 - Mezzasoma, Annamaria A1 - Minuz, Pietro A1 - Nichele, Ilaria A1 - Notarangelo, Lucia D A1 - Pippucci, Tommaso A1 - Podda, Gian Marco A1 - Pouymayou, Catherine A1 - Rigouzzo, Agnes A1 - Royer, Bruno A1 - Sie, Pierre A1 - Siguret, Virginie A1 - Trichet, Catherine A1 - Tucci, Alessandra A1 - Saposnik, Béatrice A1 - Veneri, Dino KW - Adult KW - Female KW - Humans KW - Infant, Newborn KW - Pregnancy KW - Pregnancy Complications, Hematologic KW - Retrospective Studies KW - Thrombocytopenia KW - Young Adult AB -

Pregnancy in women with inherited thrombocytopenias is a major matter of concern as both the mothers and the newborns are potentially at risk of bleeding. However, medical management of this condition cannot be based on evidence because of the lack of consistent information in the literature. To advance knowledge on this matter, we performed a multicentric, retrospective study evaluating 339 pregnancies in 181 women with 13 different forms of inherited thrombocytopenia. Neither the degree of thrombocytopenia nor the severity of bleeding tendency worsened during pregnancy and the course of pregnancy did not differ from that of healthy subjects in terms of miscarriages, fetal bleeding and pre-term births. The degree of thrombocytopenia in the babies was similar to that in the mother. Only 7 of 156 affected newborns had delivery-related bleeding, but 2 of them died of cerebral hemorrhage. The frequency of delivery-related maternal bleeding ranged from 6.8% to 14.2% depending on the definition of abnormal blood loss, suggesting that the risk of abnormal blood loss was increased with respect to the general population. However, no mother died or had to undergo hysterectomy to arrest bleeding. The search for parameters predicting delivery-related bleeding in the mother suggested that hemorrhages requiring blood transfusion were more frequent in women with history of severe bleedings before pregnancy and with platelet count at delivery below 50 × 10(9)/L.

VL - 99 IS - 8 U1 - http://www.ncbi.nlm.nih.gov/pubmed/24763399?dopt=Abstract ER - TY - JOUR T1 - Mutations in ANKRD26 are responsible for a frequent form of inherited thrombocytopenia: analysis of 78 patients from 21 families. JF - Blood Y1 - 2011 A1 - Noris, Patrizia A1 - Perrotta, Silverio A1 - Seri, Marco A1 - Pecci, Alessandro A1 - Gnan, Chiara A1 - Loffredo, Giuseppe A1 - Pujol-Moix, Núria A1 - Zecca, Marco A1 - Scognamiglio, Francesca A1 - De Rocco, Daniela A1 - Punzo, Francesca A1 - Melazzini, Federica A1 - Scianguetta, Saverio A1 - Casale, Maddalena A1 - Marconi, Caterina A1 - Pippucci, Tommaso A1 - Amendola, Giovanni A1 - Notarangelo, Lucia D A1 - Klersy, Catherine A1 - Civaschi, Elisa A1 - Balduini, Carlo L A1 - Savoia, Anna KW - Adolescent KW - Adult KW - Aged KW - Aged, 80 and over KW - Ankyrin Repeat KW - Child KW - Cohort Studies KW - Family KW - Female KW - Gene Frequency KW - Humans KW - Inheritance Patterns KW - Male KW - Middle Aged KW - Mutation KW - Pedigree KW - Thrombocytopenia KW - Transcription Factors KW - Young Adult AB -

Until recently, thrombocytopenia 2 (THC2) was considered an exceedingly rare form of autosomal dominant thrombocytopenia and only 2 families were known. However, we recently identified mutations in the 5'-untranslated region of the ANKRD26 gene in 9 THC2 families. Here we report on 12 additional pedigrees with ANKRD26 mutations, 6 of which are new. Because THC2 affected 21 of the 210 families in our database, it has to be considered one of the less rare forms of inherited thrombocytopenia. Analysis of all 21 families with ANKRD26 mutations identified to date revealed that thrombocytopenia and bleeding tendency were usually mild. Nearly all patients had no platelet macrocytosis, and this characteristic distinguishes THC2 from most other forms of inherited thrombocytopenia. In the majority of cases, platelets were deficient in glycoprotein Ia and α-granules, whereas in vitro platelet aggregation was normal. Bone marrow examination and serum thrombopoietin levels suggested that thrombocytopenia was derived from dysmegakaryopoiesis. Unexplained high values of hemoglobin and leukocytes were observed in a few cases. An unexpected finding that warrants further investigation was a high incidence of acute leukemia. Given the scarcity of distinctive characteristics, the ANKRD26-related thrombocytopenia has to be taken into consideration in the differential diagnosis of isolated thrombocytopenias.

VL - 117 IS - 24 U1 - http://www.ncbi.nlm.nih.gov/pubmed/21467542?dopt=Abstract ER - TY - JOUR T1 - Mutations in the 5' UTR of ANKRD26, the ankirin repeat domain 26 gene, cause an autosomal-dominant form of inherited thrombocytopenia, THC2. JF - Am J Hum Genet Y1 - 2011 A1 - Pippucci, Tommaso A1 - Savoia, Anna A1 - Perrotta, Silverio A1 - Pujol-Moix, Núria A1 - Noris, Patrizia A1 - Castegnaro, Giovanni A1 - Pecci, Alessandro A1 - Gnan, Chiara A1 - Punzo, Francesca A1 - Marconi, Caterina A1 - Gherardi, Samuele A1 - Loffredo, Giuseppe A1 - De Rocco, Daniela A1 - Scianguetta, Saverio A1 - Barozzi, Serena A1 - Magini, Pamela A1 - Bozzi, Valeria A1 - Dezzani, Luca A1 - Di Stazio, Mariateresa A1 - Ferraro, Marcella A1 - Perini, Giovanni A1 - Seri, Marco A1 - Balduini, Carlo L KW - Ankyrin Repeat KW - Base Sequence KW - Chromosome Breakage KW - Chromosome Disorders KW - Conserved Sequence KW - Female KW - Genes, Dominant KW - Genetic Loci KW - Haploinsufficiency KW - Humans KW - Male KW - Molecular Sequence Data KW - Mutation KW - Pedigree KW - Thrombocytopenia AB -

THC2, an autosomal-dominant thrombocytopenia described so far in only two families, has been ascribed to mutations in MASTL or ACBD5. Here, we show that ANKRD26, another gene within the THC2 locus, and neither MASTL nor ACBD5, is mutated in eight unrelated families. ANKRD26 was also found to be mutated in the family previously reported to have an ACBD5 mutation. We identified six different ANKRD26 mutations, which were clustered in a highly conserved 19 bp sequence located in the 5' untranslated region. Mutations were not detected in 500 controls and are absent from the 1000 Genomes database. Available data from an animal model and Dr. Watson's genome give evidence against haploinsufficiency as the pathogenetic mechanism for ANKRD26-mediated thrombocytopenia. The luciferase reporter assay suggests that these 5' UTR mutations might enhance ANKRD26 expression. ANKRD26 is the ancestor of a family of primate-specific genes termed POTE, which have been recently identified as a family of proapoptotic proteins. Dysregulation of apoptosis might therefore be the pathogenetic mechanism, as demonstrated for another thrombocytopenia, THC4. Further investigation is needed to provide evidence supporting this hypothesis.

VL - 88 IS - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/21211618?dopt=Abstract ER -