Paula G. Heller, Andrew D Mumford, Fabrizio Fabris, Alessandro Pecci, Silvia Riondino, Marco R. de Groot, Daniela De Rocco, Marisa Giani, Nuria Pujol-Moix, Francesca Scognamiglio, Valeria Bozzi, Marco Seri, Giuseppe Loffredo, Patrizia Noris, Anna Savoia, Raffaella Scandellari, Emanuele Panza, Carlo L. Balduini, Paolo Freddi, Savoia A., De Rocco D., Panza E., Bozzi V., Scandellari R., Loffredo G., Mumford A., Heller P.G., Noris P., De Groot M.R., Giani M., Freddi P., Scognamiglio F., Riondino S., Pujol-Moix N., Fabris F., Seri M., Balduini C.L., Pecci A., Savoia, Anna, DE ROCCO, Daniela, Panza, E, Bozzi, V, Scandellari, R, Loffredo, G, Mumford, A, Heller, Pg, Noris, P, DE GROOT, Mr, Giani, M, Freddi, P, Scognamiglio, F, Riondino, S, PUJOL MOIX, N, Fabris, F, Seri, M, Balduini, Cl, and Pecci, A.
MYH9 -related disease ( MYH9 -RD) is an autosomal dominant thrombocytopenia with giant platelets variably associated with young-adult onset of progressive sensorineural hearing loss, presenile cataract, and renal damage. MYH9 -RD is caused by mutations of MYH9 , the gene encoding for non-muscle heavy-chain myosin-9. Wild-type and mutant myosin-9 aggregate as cytoplasmic inclusions in patients’ leukocytes, the identification of which by immunofluorescence has been proposed as a suitable tool for the diagnosis of MYH9 -RD. Since the predictive value of this assay, in terms of sensitivity and specificity, is unknown, we investigated 118 consecutive unrelated patients with a clinical presentation strongly consistent with MYH9 -RD. All patients prospectively underwent both the immunofluorescence assay for myosin-9 aggregate detection and molecular genetic analysis of the MYH9 gene. Myosin-9 aggregates were identified in 82 patients, 80 of which (98%) had also a MYH9 mutation. In the remaining 36 patients neither myosin-9 aggregates nor MYH9 mutations were found. Sensitivity and specificity of the immunofluorescence assay was evaluated to be 100% and 95%, respectively. Except for the presence of aggregates, we did not find any other significant difference between patients with or without aggregates, demonstrating that the myosin-9 inclusions in neutrophils are a pathognomonic sign of the disease. However, the identification of the specific MYH9 mutation is still of importance for prognostic aspects of MYH9 -RD. Fil: Savoia, Anna. Universita Degli Studi Di Trieste; Italia. Italian Registry for MYH9-Related Disease; Italia Fil: de Rocco, Daniela. Universita Degli Studi Di Trieste; Italia. Italian Registry for MYH9-Related Disease; Italia Fil: Panza, Emanuele. Italian Registry for MYH9-Related Disease; Italia. Universita Di Bologna; Italia Fil: Bozzi, Valeria. Italian Registry for MYH9-Related Disease; Italia. University of Pavia; Italia Fil: Scandellari, Raffaella. Italian Registry for MYH9-Related Disease; Italia. Universita Di Padova; Italia Fil: Loffredo, Giuseppe. Italian Registry for MYH9-Related Disease; Italia. Pausilipon Hospital; Italia Fil: Mumford, Andrew. University of Bristol; Reino Unido Fil: Heller, Paula Graciela. Italian Registry for MYH9-Related Disease; Italia. 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; Argentina Fil: Noris, Patrizia. Italian Registry for MYH9-Related Disease; Italia Fil: de Groot, Marco R.. University of Bristol; Reino Unido Fil: Giani, Marisa. Italian Registry for MYH9-Related Disease; Italia. Istituto di Ricovero e Cura a Carattere Scientifico; Italia Fil: Freddi, Paolo. Italian Registry for MYH9-Related Disease; Italia Fil: Scognamiglio, Francesca. Italian Registry for MYH9-Related Disease; Italia Fil: Riondino, Silvia. Italian Registry for MYH9-Related Disease; Italia. Istituto di Ricovero e Cura a Carattere Scientifico; Italia Fil: Pujol Moix, Núria. Universitat Autonoma de Barcelona; España Fil: Fabris, Fabrizio. Italian Registry for MYH9-Related Disease; Italia. Universita Di Padova; Italia Fil: Seri, Marco. Italian Registry for MYH9-Related Disease; Italia. Universita Di Bologna; Italia Fil: Balduini, Carlo L.. Italian Registry for MYH9-Related Disease; Italia. University of Pavia; Italia Fil: Pecci, Alessandro. Italian Registry for MYH9-Related Disease; Italia. University of Pavia; Italia