@article {10748, title = {ACTN1 mutations lead to a benign form of platelet macrocytosis not always associated with thrombocytopenia.}, journal = {Br J Haematol}, volume = {183}, year = {2018}, month = {2018 Oct}, pages = {276-288}, abstract = {

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.

}, issn = {1365-2141}, doi = {10.1111/bjh.15531}, author = {Faleschini, Michela and Melazzini, Federica and Marconi, Caterina and Giangregorio, Tania and Pippucci, Tommaso and Cigalini, Elena and Pecci, Alessandro and Bottega, Roberta and Ramenghi, Ugo and Siitonen, Timo and Seri, Marco and Pastore, Annalisa and Savoia, Anna and Noris, Patrizia} } @article {10421, title = {Hypomorphic FANCA mutations correlate with mild mitochondrial and clinical phenotype in Fanconi anemia.}, journal = {Haematologica}, volume = {103}, year = {2018}, month = {2018 Mar}, pages = {417-426}, abstract = {

Fanconi anemia is a rare disease characterized by congenital malformations, aplastic anemia, and predisposition to cancer. Despite the consolidated role of the Fanconi anemia proteins in DNA repair, their involvement in mitochondrial function is emerging. The purpose of this work was to assess whether the mitochondrial phenotype, independent of genomic integrity, could correlate with patient phenotype. We evaluated mitochondrial and clinical features of 11 affected individuals homozygous or compound heterozygous for p.His913Pro and p.Arg951Gln/Trp, the two residues of FANCA that are more frequently affected in our cohort of patients. Although p.His913Pro and p.Arg951Gln proteins are stably expressed in cytoplasm, they are unable to migrate in the nucleus, preventing cells from repairing DNA. In these cells, the electron transfer between respiring complex I-III is reduced and the ATP/AMP ratio is impaired with defective ATP production and AMP accumulation. These activities are intermediate between those observed in wild-type and FANCA-/- cells, suggesting that the variants at residues His913 and Arg951 are hypomorphic mutations. Consistent with these findings, the clinical phenotype of most of the patients carrying these mutations is mild. These data further support the recent finding that the Fanconi anemia proteins play a role in mitochondria, and open up possibilities for genotype/phenotype studies based on novel mitochondrial criteria.

}, issn = {1592-8721}, doi = {10.3324/haematol.2017.176131}, author = {Bottega, Roberta and Nicchia, Elena and Cappelli, Enrico and Ravera, Silvia and De Rocco, Daniela and Faleschini, Michela and Corsolini, Fabio and Pierri, Filomena and Calvillo, Michaela and Russo, Giovanna and Casazza, Gabriella and Ramenghi, Ugo and Farruggia, Piero and Dufour, Carlo and Savoia, Anna} } @article {10521, title = {Defects in mitochondrial energetic function compels Fanconi Anaemia cells to glycolytic metabolism.}, journal = {Biochim Biophys Acta Mol Basis Dis}, volume = {1863}, year = {2017}, month = {2017 06}, pages = {1214-1221}, abstract = {

Energetic metabolism plays an essential role in the differentiation of haematopoietic stem cells (HSC). In Fanconi Anaemia (FA), DNA damage is accumulated during HSC differentiation, an event that is likely associated with bone marrow failure (BMF). One of the sources of the DNA damage is altered mitochondrial metabolism and an associated increment of oxidative stress. Recently, altered mitochondrial morphology and a deficit in the energetic activity in FA cells have been reported. Considering that mitochondria are the principal site of aerobic ATP production, we investigated FA metabolism in order to understand what pathways are able to compensate for this energy deficiency. In this work, we report that the impairment in mitochondrial oxidative phosphorylation (OXPHOS) in FA cells is countered by an increase in glycolytic flux. By contrast, glutaminolysis appears lower with respect to controls. Therefore, it is possible to conclude that in FA cells glycolysis represents the main pathway for producing energy, balancing the NADH/NAD ratio by the conversion of pyruvate to lactate. Finally, we show that a forced switch from glycolytic to OXPHOS metabolism increases FA cell oxidative stress. This could be the cause of the impoverishment in bone marrow HSC during exit from the homeostatic quiescent state. This is the first work that systematically explores FA energy metabolism, highlighting its flaws, and discusses the possible relationships between these defects and BMF.

}, keywords = {Cell Line, Fanconi Anemia, Glycolysis, Humans, Mitochondria, Oxidative Phosphorylation, Oxidative Stress}, issn = {0925-4439}, doi = {10.1016/j.bbadis.2017.03.008}, author = {Cappelli, Enrico and Cuccarolo, Paola and Stroppiana, Giorgia and Miano, Maurizio and Bottega, Roberta and Cossu, Vanessa and Degan, Paolo and Ravera, Silvia} } @article {10574, title = {Gray platelet syndrome: Novel mutations of the NBEAL2 gene.}, journal = {Am J Hematol}, volume = {92}, year = {2017}, month = {2017 02}, pages = {E20-E22}, keywords = {Adult, Alleles, Blood Proteins, Child, Female, Gene Expression, Gene Frequency, Genotype, Gray Platelet Syndrome, Humans, Male, Mutation, Phenotype, Platelet Aggregation, Platelet Count, Platelet Membrane Glycoproteins}, issn = {1096-8652}, doi = {10.1002/ajh.24610}, author = {Bottega, Roberta and Nicchia, Elena and Alfano, Caterina and Glembotsky, Ana C and Pastore, Annalisa and Bertaggia-Calderara, Debora and Bisig, Bettina and Duchosal, Michel A and Arbes{\'u}, Guillermo and Alberio, Lorenzo and Heller, Paula G and Savoia, Anna} } @article {10546, title = {Mutations of RUNX1 in families with inherited thrombocytopenia.}, journal = {Am J Hematol}, volume = {92}, year = {2017}, month = {2017 06}, pages = {E86-E88}, keywords = {Adult, Blood Platelets, Cell Size, Child, Child, Preschool, Core Binding Factor Alpha 2 Subunit, Female, Frameshift Mutation, Genes, Dominant, Heterozygote, Humans, Introns, Leukemia, Myeloid, Acute, Male, Middle Aged, Mutation, Missense, Protein Domains, RNA Splice Sites, Sequence Deletion, Thrombocythemia, Essential, Thrombopoietin, Transcriptional Activation, Young Adult}, issn = {1096-8652}, doi = {10.1002/ajh.24703}, author = {De Rocco, Daniela and Melazzini, Federica and Marconi, Caterina and Pecci, Alessandro and Bottega, Roberta and Gnan, Chiara and Palombo, Flavia and Giordano, Paola and Coccioli, Maria Susanna and Glembotsky, Ana C and Heller, Paula G and Seri, Marco and Savoia, Anna and Noris, Patrizia} } @article {8350, title = {Evaluation of energy metabolism and calcium homeostasis in cells affected by Shwachman-Diamond syndrome.}, journal = {Sci Rep}, volume = {6}, year = {2016}, month = {2016}, pages = {25441}, abstract = {

Isomorphic mutation of the SBDS gene causes Shwachman-Diamond syndrome (SDS). SDS is a rare genetic bone marrow failure and cancer predisposition syndrome. SDS cells have ribosome biogenesis and their protein synthesis altered, which are two high-energy consuming cellular processes. The reported changes in reactive oxygen species production, endoplasmic reticulum stress response and reduced mitochondrial functionality suggest an energy production defect in SDS cells. In our work, we have demonstrated that SDS cells display a Complex IV activity impairment, which causes an oxidative phosphorylation metabolism defect, with a consequent decrease in ATP production. These data were confirmed by an increased glycolytic rate, which compensated for the energetic stress. Moreover, the signalling pathways involved in glycolysis activation also appeared more activated; i.e. we reported AMP-activated protein kinase hyper-phosphorylation. Notably, we also observed an increase in a mammalian target of rapamycin phosphorylation and high intracellular calcium concentration levels ([Ca(2+)]i), which probably represent new biochemical equilibrium modulation in SDS cells. Finally, the SDS cell response to leucine (Leu) was investigated, suggesting its possible use as a therapeutic adjuvant to be tested in clinical trials.

}, issn = {2045-2322}, doi = {10.1038/srep25441}, author = {Ravera, Silvia and Dufour, Carlo and Cesaro, Simone and Bottega, Roberta and Faleschini, Michela and Cuccarolo, Paola and Corsolini, Fabio and Usai, Cesare and Columbaro, Marta and Cipolli, Marco and Savoia, Anna and Degan, Paolo and Cappelli, Enrico} } @article {3633, title = {ACTN1-related thrombocytopenia: identification of novel families for phenotypic characterization.}, journal = {Blood}, volume = {125}, year = {2015}, month = {2015 Jan 29}, pages = {869-72}, abstract = {

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.

}, keywords = {Actinin, Adolescent, Adult, Aged, Aged, 80 and over, Blood Platelets, Case-Control Studies, Child, Child, Preschool, Female, Gene Expression, Genotype, Heterozygote, Humans, Male, Middle Aged, Mutation, Missense, Pedigree, Phenotype, Platelet Count, Severity of Illness Index, Thrombocytopenia, Thrombopoiesis, Thrombopoietin}, issn = {1528-0020}, doi = {10.1182/blood-2014-08-594531}, author = {Bottega, Roberta and Marconi, Caterina and Faleschini, Michela and Baj, Gabriele and Cagioni, Claudia and Pecci, Alessandro and Pippucci, Tommaso and Ramenghi, Ugo and Pardini, Simonetta and Ngu, Loretta and Baronci, Carlo and Kunishima, Shinji and Balduini, Carlo L and Seri, Marco and Savoia, Anna and Noris, Patrizia} } @article {7698, title = {Clinical aspects of Fanconi anemia individuals with the same mutation of FANCF identified by next generation sequencing.}, journal = {Birth Defects Res A Clin Mol Teratol}, volume = {103}, year = {2015}, month = {2015 Dec}, pages = {1003-1010}, abstract = {

BACKGROUND: Fanconi anemia (FA) is a rare genetic disease characterized by congenital malformations, aplastic anemia and increased risk of developing malignancies. FA is genetically heterogeneous as it is caused by at least 17 different genes. Among these, FANCA, FANCC, and FANCG account for approximately 85\% of the patients whereas the remaining genes are mutated in only a small percentage of cases. For this reason, the molecular diagnostic process is complex and not always extended to all the FA genes, preventing the characterization of individuals belonging to rare groups.

METHODS: The FA genes were analyzed using a next generation sequencing approach in two unrelated families.

RESULTS: The analysis identified the same, c.484_485del, homozygous mutation of FANCF in both families. A careful examination of three electively aborted fetuses in one family and one affected girl in the other indicated an association of the FANCF loss-of-function mutation with a severe phenotype characterized by multiple malformations.

CONCLUSION: The systematic use of next generation sequencing will allow the recognition of individuals from rare complementation groups, a better definition of their clinical phenotypes, and consequently, an appropriate genetic counseling. Birth Defects Research (Part A) 103:1003-1010, 2015. {\textcopyright} 2015 Wiley Periodicals, Inc.

}, issn = {1542-0760}, doi = {10.1002/bdra.23388}, author = {Nicchia, Elena and Benedicenti, Francesco and Rocco, Daniela De and Greco, Chiara and Bottega, Roberta and Inzana, Francesca and Faleschini, Michela and Bonin, Serena and Cappelli, Enrico and Mogni, Massimo and Stanzial, Franco and Svahn, Johanna and Dufour, Carlo and Savoia, Anna} } @article {3554, title = {Analysis of 339 pregnancies in 181 women with 13 different forms of inherited thrombocytopenia.}, journal = {Haematologica}, volume = {99}, year = {2014}, month = {2014 Aug}, pages = {1387-94}, abstract = {

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 {\texttimes} 10(9)/L.

}, keywords = {Adult, Female, Humans, Infant, Newborn, Pregnancy, Pregnancy Complications, Hematologic, Retrospective Studies, Thrombocytopenia, Young Adult}, issn = {1592-8721}, doi = {10.3324/haematol.2014.105924}, author = {Noris, Patrizia and Schlegel, Nicole and Klersy, Catherine and Heller, Paula G and Civaschi, Elisa and Pujol-Moix, N{\'u}ria and Fabris, Fabrizio and Favier, R{\'e}mi and Gresele, Paolo and Latger-Cannard, V{\'e}ronique and Cuker, Adam and Nurden, Paquita and Greinacher, Andreas and Cattaneo, Marco and De Candia, Erica and Pecci, Alessandro and Hurtaud-Roux, Marie-Fran{\c c}oise and Glembotsky, Ana C and Mu{\~n}iz-Diaz, Eduardo and Randi, Maria Luigia and Trillot, Nathalie and Bury, Loredana and Lecompte, Thomas and Marconi, Caterina and Savoia, Anna and Balduini, Carlo L and Bayart, Sophie and Bauters, Anne and Benabdallah-Guedira, Sch{\'e}h{\'e}razade and Boehlen, Fran{\c c}oise and Borg, Jeanne-Yvonne and Bottega, Roberta and Bussel, James and De Rocco, Daniela and de Maistre, Emmanuel and Faleschini, Michela and Falcinelli, Emanuela and Ferrari, Silvia and Ferster, Alina and Fierro, Tiziana and Fleury, Dominique and Fontana, Pierre and James, Chlo{\'e} and Lanza, Francois and Le Cam Duchez, V{\'e}ronique and Loffredo, Giuseppe and Magini, Pamela and Martin-Coignard, Dominique and Menard, Fanny and Mercier, Sandra and Mezzasoma, Annamaria and Minuz, Pietro and Nichele, Ilaria and Notarangelo, Lucia D and Pippucci, Tommaso and Podda, Gian Marco and Pouymayou, Catherine and Rigouzzo, Agnes and Royer, Bruno and Sie, Pierre and Siguret, Virginie and Trichet, Catherine and Tucci, Alessandra and Saposnik, B{\'e}atrice and Veneri, Dino} } @article {3549, title = {Molecular analysis of Fanconi anemia: the experience of the Bone Marrow Failure Study Group of the Italian Association of Pediatric Onco-Hematology.}, journal = {Haematologica}, volume = {99}, year = {2014}, month = {2014 Jun}, pages = {1022-31}, abstract = {

Fanconi anemia is an inherited disease characterized by congenital malformations, pancytopenia, cancer predisposition, and sensitivity to cross-linking agents. The molecular diagnosis of Fanconi anemia is relatively complex for several aspects including genetic heterogeneity with mutations in at least 16 different genes. In this paper, we report the mutations identified in 100 unrelated probands enrolled into the National Network of the Italian Association of Pediatric Hematoly and Oncology. In approximately half of these cases, mutational screening was carried out after retroviral complementation analyses or protein analysis. In the other half, the analysis was performed on the most frequently mutated genes or using a next generation sequencing approach. We identified 108 distinct variants of the FANCA, FANCG, FANCC, FANCD2, and FANCB genes in 85, 9, 3, 2, and 1 families, respectively. Despite the relatively high number of private mutations, 45 of which are novel Fanconi anemia alleles, 26\% of the FANCA alleles are due to 5 distinct mutations. Most of the mutations are large genomic deletions and nonsense or frameshift mutations, although we identified a series of missense mutations, whose pathogenetic role was not always certain. The molecular diagnosis of Fanconi anemia is still a tiered procedure that requires identifying candidate genes to avoid useless sequencing. Introduction of next generation sequencing strategies will greatly improve the diagnostic process, allowing a rapid analysis of all the genes.

}, keywords = {Amino Acid Substitution, Cell Line, Cohort Studies, Computational Biology, Databases, Nucleic Acid, Fanconi Anemia, Fanconi Anemia Complementation Group Proteins, Founder Effect, Genotype, Humans, Italy, Mosaicism, Mutation, Polymorphism, Single Nucleotide}, issn = {1592-8721}, doi = {10.3324/haematol.2014.104224}, author = {De Rocco, Daniela and Bottega, Roberta and Cappelli, Enrico and Cavani, Simona and Criscuolo, Maria and Nicchia, Elena and Corsolini, Fabio and Greco, Chiara and Borriello, Adriana and Svahn, Johanna and Pillon, Marta and Mecucci, Cristina and Casazza, Gabriella and Verzegnassi, Federico and Cugno, Chiara and Locasciulli, Anna and Farruggia, Piero and Longoni, Daniela and Ramenghi, Ugo and Barberi, Walter and Tucci, Fabio and Perrotta, Silverio and Grammatico, Paola and Hanenberg, Helmut and Della Ragione, Fulvio and Dufour, Carlo and Savoia, Anna} } @article {1993, title = {MYH9-related disease: five novel mutations expanding the spectrum of causative mutations and confirming genotype/phenotype correlations.}, journal = {Eur J Med Genet}, volume = {56}, year = {2013}, month = {2013 Jan}, pages = {7-12}, abstract = {

MYH9-related disease (MYH9-RD) is a rare autosomal dominant syndromic disorder caused by mutations in MYH9, the gene encoding for the heavy chain of non-muscle myosin IIA (myosin-9). MYH9-RD is characterized by congenital macrothrombocytopenia and typical inclusion bodies in neutrophils associated with a variable risk of developing sensorineural deafness, presenile cataract, and/or progressive nephropathy. The spectrum of mutations responsible for MYH9-RD is limited. We report five families, each with a novel MYH9 mutation. Two mutations, p.Val34Gly and p.Arg702Ser, affect the motor domain of myosin-9, whereas the other three, p.Met847_Glu853dup, p.Lys1048_Glu1054del, and p.Asp1447Tyr, hit the coiled-coil tail domain of the protein. The motor domain mutations were associated with more severe clinical phenotypes than those in the tail domain.

}, keywords = {Adolescent, Adult, Amino Acid Sequence, Amino Acid Substitution, Base Sequence, Child, Child, Preschool, Exons, Female, Genes, Dominant, Genetic Association Studies, Humans, Male, Middle Aged, Models, Molecular, Molecular Motor Proteins, Molecular Sequence Data, Mutation, Myosin Heavy Chains, Pedigree, Protein Conformation, Sequence Alignment, Syndrome, Thrombocytopenia, Young Adult}, issn = {1878-0849}, doi = {10.1016/j.ejmg.2012.10.009}, author = {De Rocco, Daniela and Zieger, Barbara and Platokouki, Helen and Heller, Paula G and Pastore, Annalisa and Bottega, Roberta and Noris, Patrizia and Barozzi, Serena and Glembotsky, Ana C and Pergantou, Helen and Balduini, Carlo L and Savoia, Anna and Pecci, Alessandro} } @article {1922, title = {Clinical and laboratory features of 103 patients from 42 Italian families with inherited thrombocytopenia derived from the monoallelic Ala156Val mutation of GPIbα (Bolzano mutation).}, journal = {Haematologica}, volume = {97}, year = {2012}, month = {2012 Jan}, pages = {82-8}, abstract = {

BACKGROUND: Bernard-Soulier syndrome is a very rare form of inherited thrombocytopenia that derives from mutations in GPIbα, GPIbβ, or GPIX and is typically inherited as a recessive disease. However, some years ago it was shown that the monoallelic c.515C>T transition in the GPIBA gene (Bolzano mutation) was responsible for macrothrombocytopenia in a few Italian patients.

DESIGN AND METHODS: Over the past 10 years, we have searched for the Bolzano mutation in all subjects referred to our institutions because of an autosomal, dominant form of thrombocytopenia of unknown origin.

RESULTS: We identified 42 new Italian families (103 cases) with a thrombocytopenia induced by monoallelic Bolzano mutation. Analyses of the geographic origin of affected pedigrees and haplotypes indicated that this mutation originated in southern Italy. Although the clinical expression was variable, patients with this mutation typically had a mild form of Bernard-Soulier syndrome with mild thrombocytopenia and bleeding tendency. The most indicative laboratory findings were enlarged platelets and reduced GPIb/IX/V platelet expression; in vitro platelet aggregation was normal in nearly all of the cases.

CONCLUSIONS: Our study indicates that monoallelic Bolzano mutation is the most frequent cause of inherited thrombocytopenia in Italy, affecting 20\% of patients recruited at our institutions during the last 10 years. Because many people from southern Italy have emigrated during the last century, this mutation may have spread to other countries.

}, keywords = {Adolescent, Adult, Aged, Aged, 80 and over, Bernard-Soulier Syndrome, Child, Child, Preschool, Family Health, Female, Heterozygote, Humans, Infant, Italy, Male, Membrane Glycoproteins, Middle Aged, Mutation, Missense, Platelet Aggregation, Platelet Count, Platelet Glycoprotein GPIb-IX Complex, Polymorphism, Genetic, Thrombocytopenia, Thrombopoietin, Tubulin, Young Adult}, issn = {1592-8721}, doi = {10.3324/haematol.2011.050682}, author = {Noris, Patrizia and Perrotta, Silverio and Bottega, Roberta and Pecci, Alessandro and Melazzini, Federica and Civaschi, Elisa and Russo, Sabina and Magrin, Silvana and Loffredo, Giuseppe and Di Salvo, Veronica and Russo, Giovanna and Casale, Maddalena and De Rocco, Daniela and Grignani, Claudio and Cattaneo, Marco and Baronci, Carlo and Dragani, Alfredo and Albano, Veronica and Jankovic, Momcilo and Scianguetta, Saverio and Savoia, Anna and Balduini, Carlo L} } @article {1697, title = {Clinical and genetic aspects of Bernard-Soulier syndrome: searching for genotype/phenotype correlations.}, journal = {Haematologica}, volume = {96}, year = {2011}, month = {2011 Mar}, pages = {417-23}, abstract = {

BACKGROUND: Bernard-Soulier syndrome is a severe bleeding disease due to a defect of GPIb/IX/V, a platelet complex that binds the von Willebrand factor. Due to the rarity of the disease, there are reports only on a few cases compromising any attempt to establish correlations between genotype and phenotype. In order to identify any associations, we describe the largest case series ever reported, which was evaluated systematically at the same center.

DESIGN AND METHODS: Thirteen patients with the disease and seven obligate carriers were enrolled. We collected clinical aspects and determined platelet features, including number and size, expression of membrane glycoproteins, and ristocetin induced platelet aggregation. Mutations were identified by direct sequencing of the GP1BA, GP1BB, and GP9 genes and their effect was shown by molecular modeling analyses.

RESULTS: Patients all had a moderate thrombocytopenia with giant platelets and a bleeding tendency whose severity varied among individuals. Consistent with expression levels of GPIbα always lower than 10\% of control values, platelet aggregation was absent or severely reduced. Homozygous mutations were identified in the GP1BA, GP1BB and GP9 genes; six were novel alterations expected to destabilize the conformation of the respective protein. Except for obligate carriers of a GP9 mutation with a reduced GPIb/IX/V expression and defective aggregation, all the other carriers had no obvious anomalies.

CONCLUSIONS: Regardless of mutations identified, the patients{\textquoteright} bleeding diathesis did not correlate with thrombocytopenia, which was always moderate, and platelet GPIbα expression, which was always severely impaired. Obligate carriers had features similar to controls though their GPIb/IX/V expression showed discrepancies. Aware of the limitations of our cohort, we cannot define any correlations. However, further investigations should be encouraged to better understand the causes of this rare and underestimated disease.

}, keywords = {Adolescent, Adult, Amino Acid Sequence, Bernard-Soulier Syndrome, Blood Platelets, Cell Shape, Child, Child, Preschool, Female, Genetic Association Studies, Genetic Markers, Hemorrhage, Homozygote, Humans, Italy, Male, Membrane Glycoproteins, Middle Aged, Molecular Sequence Data, Platelet Aggregation, Platelet Count, Platelet Glycoprotein GPIb-IX Complex, Point Mutation, Polymerase Chain Reaction, Ristocetin, Thrombocytopenia, von Willebrand Factor, Young Adult}, issn = {1592-8721}, doi = {10.3324/haematol.2010.032631}, author = {Savoia, Anna and Pastore, Annalisa and De Rocco, Daniela and Civaschi, Elisa and Di Stazio, Mariateresa and Bottega, Roberta and Melazzini, Federica and Bozzi, Valeria and Pecci, Alessandro and Magrin, Silvana and Balduini, Carlo L and Noris, Patrizia} }