Patients' enrolment and scientific production
The number of patients enrolled in the Registry (www.registromyh9.org) is continuously growing. Since its institution in 2007, 727 patients with thrombocytopenia have been screened for MYH9-related disease and in 202 of them the diagnosis has been confirmed at the molecular level. The Registry case series now includes patients with 30 different mutations affecting 24 residues of the MYH9 protein: 19 missense mutations, 8 nonsense or frameshift alterations, two in frame deletions, and the only duplication responsible for this disorder. Due to the recent opening to foreign Institutions, the database now includes patients from 19 different countries. In this 4-years activity, more than 30 groups published 14 scientific papers on different aspects of the MYH9-related disease by using the case series collected by the Registry.
Eltrompobag, a new therapeutic option for patients with MYH9-related thrombocytopenia
Two groups of the Registry recently published the results of a clinical trial that demonstrated the efficacy of Eltrombopag, a thrombopoietin receptor agonist, in increasing the platelet count of patients with MYH9-related disease (Blood 2010 Sep 15, Epub ahead of print). This is the first study that identifies a drug therapy for patients with inherited thrombocytopenia. We are confident that Eltrombopag will be available shortly for the treatment of these patients, not only to reduce spontaneous bleeding in subjects with severe thrombocytopenia, but also to increase the platelet count in preparation for invasive procedures without resorting to platelet transfusions. We trust that these results may pave the road to test the thrombopoietin analogues also in patients with other forms of inherited thrombocytopenia.
The study of the first 108 enrolled patients allowed to propose a model to predict the natural history of the disease on the basis of the MYH9 genotype (Hum Mutat 2008;29:409). The analysis of about 100 further patients, as well as the follow-up of the already reported subjects, will extend and refine this prognostic model, significantly improving our ability to predict the development of kidney, hearing, and sight impairment in these subjects. Unfortunately, for some of the patients already characterized for genotype, the clinical phenotype data are incomplete or have not recently updated. We are contacting Colleagues who already enrolled patients to request the inclusion in the database of any missing data. However, we invite all participating centres to speed up the collection and entry of missing data, in order to produce a case series as complete as possible and publish a new paper on this matter.
Finally, we invite all the Colleagues who follows patients with thrombocytopenia of suspected genetic origin to send the samples for the screening assays as soon as possible in order to participate in this study.
Sharing the tools for the diagnosis of MYH9-related disease
Despite the cutback in funds for scientific research in Italy, the Registry will continue to perform the screening tests to confirm or exclude the diagnosis of MYH9-related thrombocytopenia free of charge. Thus, the Registry wishes to continue to be an important resource for all the people involved in the diagnosis of thrombocytopenias in Italy and Europe.