Kamila Janusz, Susana Riesco, José Ramón González-Porras, María Fernanda López-Fernández, Maria Luisa Lozano, Jesus M Hernández-Sánchez, Steve P. Watson, Anna E. Marneth, Bert A. van der Reijden, Agustín Rodriguez-Alén, José María Bastida, José Rivera, Mónica del Rey, Carlos Aguilar, Neil V. Morgan, Jesús M. Hernández-Rivas, Nuria Bermejo, Rocío Benito, Verónica Palma-Barqueros, Hermenegildo González-García, Teresa Sevivas, Vicente Vicente, Fundación Séneca, Sociedad Española de Trombosis y Hemostasia, European Commission, Instituto de Salud Carlos III, Junta de Castilla y León, and British Heart Foundation more...
Inherited platelet disorders are a heterogeneous group of rare diseases, caused by inherited defects in platelet production and/or function. Their genetic diagnosis would benefit clinical care, prognosis and preventative treatments. Until recently, this diagnosis has usually been performed via Sanger sequencing of a limited number of candidate genes. High-throughput sequencing is revolutionizing the genetic diagnosis of diseases, including bleeding disorders. We have designed a novel high-throughput sequencing platform to investigate the unknown molecular pathology in a cohort of 82 patients with inherited platelet disorders. Thirty-four (41.5%) patients presented with a phenotype strongly indicative of a particular type of platelet disorder. The other patients had clinical bleeding indicative of platelet dysfunction, but with no identifiable features. The high-throughput sequencing test enabled a molecular diagnosis in 70% of these patients. This sensitivity increased to 90% among patients suspected of having a defined platelet disorder. We found 57 different candidate variants in 28 genes, of which 70% had not previously been described. Following consensus guidelines, we qualified 68.4% and 26.3% of the candidate variants as being pathogenic and likely pathogenic, respectively. In addition to establishing definitive diagnoses of well-known inherited platelet disorders, high-throughput sequencing also identified rarer disorders such as sitosterolemia, filamin and actinin deficiencies, and G protein-coupled receptor defects. This included disease-causing variants in DIAPH1 (n=2) and RASGRP2 (n=3). Our study reinforces the feasibility of introducing high-throughput sequencing technology into the mainstream laboratory for the genetic diagnostic practice in inherited platelet disorders., This study was supported by research grants from the Gerencia Regional de Salud (GRS 1370/A/16), ISCIII & Feder (PI14/01956), CIBERER CB15/00055, Fundación Séneca (19873/GERM/15) and Sociedad Española de Trombosis y Hemostasia (SETH). SPW holds a British Heart Foundation chair. more...