Mutation analysis of HPS1, the gene mutated in Hermansky-Pudlak syndrome, in patients with isolated platelet dense-granule deficiency

Background and objectives: isolated platelet dense granule (PDG) deficiency is a heterogeneous disorder frequently found among patients with mild to moderate bleeding diatheses. However, the molecular basis of this disorder is unknown. Genes involved in other rare bleeding disorders with associated reduction in the numbers of platelet dense-granules may play a role in isolated PDG deficiency. Among such genes, HPS1 is known to play a key role in the genesis of PDG and as many as 18 different HPS1 mutations have been identified in patients with Hermansky-Pudlak syndrome. Recently, we have identified subjects with one HPS1 heterozygous mutation displaying significant reductions in PDG without the clinical phenotype of Hermansky-Pudlak syndrome. This suggested that HPS1 mutations could be involved in isolated PDG deficiency. Design and methods: we sequenced all coding exons, and flanking intron regions of HPS1 in 16 patients with mild to severe PDG deficiency, most of whom had mild bleeding episodes. Nine patients reported a familial history of bleeding diathesis with PDG deficiency. We also evaluated the prevalence of HPS1 variations in 215 controls. Transmission electron microscopy was used to evaluate the number and morphology of PDG from patients and selected controls. Results: no patient with PDG deficiency carried severe mutations of the HPS1 gene. We identified 6 previously described and 5 new polymorphisms in the HPS1 gene. Platelet electron microscopy in controls carrying these polymorphisms revealed that they did not significantly modify the number or morphology of PDG. Interpretation and conclusions: mutations affecting the HPS1 gene play a minor role in isolated PDG deficiency. These results support a molecular heterogeneity responsible for the number and morphology of PDG

Phosphotyrosine proteins in platelets from patients with storage pool disease: direct relation between granule defects and defective signal transduction

Background and objectives: storage pool diseases (SPD) are heterogeneous disorders associated with an abnormal presence of intraplatelet granules, which cause mild to moderate bleeding diathesis. We investigated signaling through tyrosine phosphorylation of proteins occurring in platelets with total or partial absence of dense- and alpha-granules in response to activation. Design and methods: we included a patient with severe delta-SPD, a patient with severe alpha-SPD or gray platelet syndrome, and six patients with partial deficiency of dense or a-granules. SPD was confirmed by electron microscopy evaluation of platelet ultrastructure. Platelet function was evaluated by bleeding time determination and conventional aggregometry. Platelet suspensions were activated with collagen and thrombin to analyze changes in tyrosine phosphorylation of proteins by electrophoresis and Western-blotting. Results: bleeding times were prolonged in all the patients included. Aggregation responses were slightly decreased in delta-SPD and normal in the rest of patients. Tyrosine phosphorylation in platelets from patients with partial forms of SPD was equivalent to that observed in control platelets, absent in response to collagen and thrombin activation in delta-SPD, and deficient only to thrombin activation in alpha-SPD. Interpretation and conclusions: tyrosine phosphorylation of proteins in activated platelets is highly dependent on the substances contained in the dense-granules and moderately dependent on those contained in the alpha-granules. A minimum amount of intraplatelet granules ensures signaling through tyrosine phosphorylation of proteins

Púrpura trombopénica inmune : múltiples tratamientos para una enfermedad

En el present treball es descriuen les principals característiques clíniques de la purpura trombopènica immune, com ara, la distribució per sexes, edat, la presència d'hemorràgies en el moment del diagnòstic i la seva gravetat, la xifra de plaquetes i la presència d'anticossos antiplaquetars. Posteriorment es valora el tractament de primera línia escollit enfront de la malaltia i la resposta aconseguida pel que fa a la xifra de plaquetes i hemostàtica, així com si s'han produït efectes secundaris, observant si succeeixen recidives posteriors i quins tractaments s'han aplicat davant elles i la resposta a aquests.En el presente trabajo se describen las principales características clínicas de la púrpura trombopénica inmune, tales como, la distribución por sexos, edad, la presencia de hemorragias en el momento del diagnóstico y su gravedad, la cifra de plaquetas y la presencia de anticuerpos antiplaquetares. Posteriormente se valora el tratamiento de primera línea escogido frente a la enfermedad y la respuesta alcanzada en cuanto a la cifra de plaquetas y hemostática, así como si se han producido efectos secundarios, observando si ocurren recidivas posteriores y que tratamientos se han aplicado ante las mismas y la respuesta a estos

Analysis of 339 pregnancies in 181 women with 13 different forms of inherited thrombocytopenia

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.Fil: Noris, Patrizia. Istituti di Ricovero e Cura a Carattere Scientifico. Policlinico San Matteo di Pavia; Italia. Università degli Studi di Pavia; ItaliaFil: Schlegel, Nicole. Université Paris Diderot - Paris 7; FranciaFil: Klersy, Catherine. Istituti di Ricovero e Cura a Carattere Scientifico. Policlinico San Matteo di Pavia; ItaliaFil: Heller, Paula Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Médicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Civaschi, Elisa. Università degli Studi di Pavia; ItaliaFil: Pujol Moix, Nuria. Universitat Autònoma de Barcelona; EspañaFil: Fabris, Fabrizio. Università di Padova; ItaliaFil: Favier, Remi. Inserm; Francia. Armand Trousseau Children’s Hospital; Francia. French Reference Center for Inherited Platelet disorders; FranciaFil: Gresele, Paolo. Università di Perugia; ItaliaFil: Latger Cannard, Véronique. Centre Hospitalo-Universitaire. Service d’Hématologie Biologique; Francia. Reference French Centre. Centre de Compétence Nord-Est des Pathologies Plaquettaires; FranciaFil: Cuker, Adam. University of Pennsylvania; Estados UnidosFil: Nurden, Paquita. Hôpital Xavier Arnozan; FranciaFil: Greinacher, Andreas. Institut für Immunologie und Transfusionsmedizin; AlemaniaFil: Cattaneo, Marco. Università degli Studi di Milano; ItaliaFil: De Candia, Erica. Università Cattolica del Sacro Cuore; ItaliaFil: Pecci, Alessandro. Università degli Studi di Pavia; ItaliaFil: Hurtaud Roux, Marie Françoise. Université Paris Diderot - Paris 7; FranciaFil: Glembotsky, Ana Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Médicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Muñiz Diaz, Eduardo. Banc de Sang i Teixits de Catalunya. Immunohematology Department; EspañaFil: Randi, Maria Luigia. Università di Padova; ItaliaFil: Trillot, Nathalie. Centre Hospitalier Régional Universitaire de Lille. Pôle Biologie Pathologie Génétique. Institut d’Hématologie-Transfusion; FranciaFil: Bury, Loredana. Università di Perugia; ItaliaFil: Lecompte, Thomas. Hôpitaux Universitaires de Genève; Suiza. Université de Genève. Faculté de Médecine; SuizaFil: Marconi, Caterina. Università di Bologna; ItaliaFil: Savoia, Anna. Università degli Studi di Trieste; ItaliaFil: Balduini, Carlo L.. Istituti di Ricovero e Cura a Carattere Scientifico Burlo Garofolo. Institute for Maternal and Child Health; Italia. Università degli Studi di Pavia; ItaliaFil: European Hematology Association Scientific Working Group on Thrombocytopenias and Platelet Function Disorders. No especifica

Analysis of 339 pregnancies in 181 women with 13 different forms of inherited thrombocytopenia

65Pregnancy 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.openopenPatrizia Noris; Nicole Schlegel; Catherine Klersy; Paula G. Heller; Elisa Civaschi; Nuria Pujol-Moix; Fabrizio Fabris; Remi Favier; Paolo Gresele; Véronique Latger-Cannard; Adam Cuker; Paquita Nurden; Andreas Greinacher; Marco Cattaneo; Erica De Candia; Alessandro Pecci; Marie-Françoise Hurtaud-Roux; Ana C. Glembotsky; Eduardo Muñiz-Diaz; Maria Luigia Randi; Nathalie Trillot; Loredana Bury; Thomas Lecompte; Caterina Marconi; Anna Savoia; Carlo L. Balduini; Sophie Bayart; Anne Bauters; Schéhérazade Benabdallah-Guedira; Françoise Boehlen; Jeanne-Yvonne Borg; Roberta Bottega; James Bussel; Daniela De Rocco; Emmanuel de Maistre; Michela Faleschini; Emanuela Falcinelli; Silvia Ferrari; Alina Ferster; Tiziana Fierro; Dominique Fleury; Pierre Fontana; Chloé James; Francois Lanza; Véronique Le Cam Duchez; Giuseppe Loffredo; Pamela Magini; Dominique Martin-Coignard; Fanny Menard; Sandra Mercier; Annamaria Mezzasoma; Pietro Minuz; Ilaria Nichele; Lucia D. Notarangelo; Tommaso Pippucci; Gian Marco Podda; Catherine Pouymayou; Agnes Rigouzzo; Bruno Royer; Pierre Sie; Virginie Siguret; Catherine Trichet; Alessandra Tucci; Béatrice Saposnik; Dino VeneriPatrizia, Noris; Nicole, Schlegel; Catherine, Klersy; Paula G., Heller; Elisa, Civaschi; Nuria Pujol, Moix; Fabrizio, Fabris; Remi, Favier; Paolo, Gresele; Véronique Latger, Cannard; Adam, Cuker; Paquita, Nurden; Andreas, Greinacher; Marco, Cattaneo; Erica De, Candia; Alessandro, Pecci; Marie Françoise Hurtaud, Roux; Ana C., Glembotsky; Eduardo Muñiz, Diaz; Maria Luigia, Randi; Nathalie, Trillot; Loredana, Bury; Thomas, Lecompte; Caterina, Marconi; Savoia, Anna; Carlo L., Balduini; Sophie, Bayart; Anne, Bauters; Schéhérazade Benabdallah, Guedira; Françoise, Boehlen; Jeanne Yvonne, Borg; Bottega, Roberta; James, Bussel; DE ROCCO, Daniela; Emmanuel de, Maistre; Faleschini, Michela; Emanuela, Falcinelli; Silvia, Ferrari; Alina, Ferster; Tiziana, Fierro; Dominique, Fleury; Pierre, Fontana; Chloé, James; Francois, Lanza; Véronique Le Cam, Duchez; Giuseppe, Loffredo; Pamela, Magini; Dominique Martin, Coignard; Fanny, Menard; Sandra, Mercier; Annamaria, Mezzasoma; Pietro, Minuz; Ilaria, Nichele; Lucia D., Notarangelo; Tommaso, Pippucci; Gian Marco, Podda; Catherine, Pouymayou; Agnes, Rigouzzo; Bruno, Royer; Pierre, Sie; Virginie, Siguret; Catherine, Trichet; Alessandra, Tucci; Béatrice, Saposnik; Dino, Vener

Púrpura trombopénica inmune : múltiples tratamientos para una enfermedad

En el present treball es descriuen les principals característiques clíniques de la purpura trombopènica immune, com ara, la distribució per sexes, edat, la presència d'hemorràgies en el moment del diagnòstic i la seva gravetat, la xifra de plaquetes i la presència d'anticossos antiplaquetars. Posteriorment es valora el tractament de primera línia escollit enfront de la malaltia i la resposta aconseguida pel que fa a la xifra de plaquetes i hemostàtica, així com si s'han produït efectes secundaris, observant si succeeixen recidives posteriors i quins tractaments s'han aplicat davant elles i la resposta a aquests.En el presente trabajo se describen las principales características clínicas de la púrpura trombopénica inmune, tales como, la distribución por sexos, edad, la presencia de hemorragias en el momento del diagnóstico y su gravedad, la cifra de plaquetas y la presencia de anticuerpos antiplaquetares. Posteriormente se valora el tratamiento de primera línea escogido frente a la enfermedad y la respuesta alcanzada en cuanto a la cifra de plaquetas y hemostática, así como si se han producido efectos secundarios, observando si ocurren recidivas posteriores y que tratamientos se han aplicado ante las mismas y la respuesta a estos

Nonmuscle Myosin Heavy Chain IIA Mutation Predicts Severity and Progression of Sensorineural Hearing Loss in Patients With MYH9-Related Disease

OBJECTIVES: MYH9-related disease (MYH9-RD) is an autosomal- dominant disorder deriving from mutations in MYH9, the gene for the nonmuscle myosin heavy chain (NMMHC)-IIA. MYH9-RD has a complex phenotype including congenital features, such as thrombocytopenia, and noncongenital manifestations, namely sensorineural hearing loss (SNHL), nephropathy, cataract, and liver abnormalities. The disease is caused by a limited number of mutations affecting different regions of the NMMHC-IIA protein. SNHL is the most frequent noncongenital manifestation of MYH9-RD. However, only scarce and anecdotal information is currently available about the clinical and audiometric features of SNHL of MYH9-RD subjects. The objective of this study was to investigate the severity and propensity for progression of SNHL in a large series of MYH9-RD patients in relation to the causative NMMHC-IIA mutations. DESIGN: This study included the consecutive patients diagnosed with MYH9-RD between July 2007 and March 2012 at four participating institutions. A total of 115 audiograms were analyzed from 63 patients belonging to 45 unrelated families with different NMMHC-IIA mutations. Cross-sectional analyses of audiograms were performed. Regression analysis was performed, and age-related typical audiograms (ARTAs) were derived to characterize the type of SNHL associated with different mutations. RESULTS: Severity of SNHL appeared to depend on the specific NMMHC-IIA mutation. Patients carrying substitutions at the residue R702 located in the short functional SH1 helix had the most severe degree of SNHL, whereas patients with the p.E1841K substitution in the coiled-coil region or mutations at the nonhelical tailpiece presented a mild degree of SNHL even at advanced age. The authors also disclosed the effects of different amino acid changes at the same residue: for instance, individuals with the p.R702C mutation had more severe SNHL than those with the p.R702H mutation, and the p.R1165L substitution was associated with a higher degree of hearing loss than the p.R1165C. In general, mild SNHL was associated with a fairly flat audiogram configuration, whereas severe SNHL correlated with downsloping configurations. ARTA plots showed that the most progressive type of SNHL was associated with the p.R702C, the p.R702H, and the p.R1165L substitutions, whereas the p.R1165C mutation correlated with a milder, nonprogressive type of SNHL than the p.R1165L. ARTA for the p.E1841K mutation demonstrated a mild degree of SNHL with only mild progression, whereas the ARTA for the mutations at the nonhelical tailpiece did not show any substantial progression. CONCLUSIONS: These data provide useful tools to predict the progression and the expected degree of severity of SNHL in individual MYH9-RD patients, which is especially relevant in young patients. Consequences in clinical practice are important not only for appropriate patient counseling but also for development of customized, genotype-driven clinical management. The authors recently reported that cochlear implantation has a good outcome in MYH9-RD patients; thus, stricter follow-up and earlier intervention are recommended for patients with unfavorable genotypes