| 1. |
- Cordeddu, Viviana, et al.
(författare)
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Activating Mutations Affecting the Dbl Homology Domain of SOS2 Cause Noonan Syndrome
- 2015
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Ingår i: Human Mutation. - : WILEY-BLACKWELL. - 1059-7794 .- 1098-1004. ; 36:11, s. 1080-1087
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Tidskriftsartikel (refereegranskat)abstract
- The RASopathies constitute a family of autosomal-dominant disorders whose major features include facial dysmorphism, cardiac defects, reduced postnatal growth, variable cognitive deficits, ectodermal and skeletal anomalies, and susceptibility to certain malignancies. Noonan syndrome (NS), the commonest RASopathy, is genetically heterogeneous and caused by functional dysregulation of signal transducers and regulatory proteins with roles in the RAS/extracellular signal-regulated kinase (ERK) signal transduction pathway. Mutations in known disease genes account for approximately 80% of affected individuals. Here, we report that missense mutations altering Son of Sevenless, Drosophila, homolog 2 (SOS2), which encodes a RAS guanine nucleotide exchange factor, occur in a small percentage of subjects with NS. Four missense mutations were identified in five unrelated sporadic cases and families transmitting NS. Disease-causing mutations affected three conserved residues located in the Dbl homology (DH) domain, of which two are directly involved in the intramolecular binding network maintaining SOS2 in its autoinhibited conformation. All mutations were found to promote enhanced signaling from RAS to ERK. Similar to NS-causing SOS1 mutations, the phenotype associated with SOS2 defects is characterized by normal development and growth, as well as marked ectodermal involvement. Unlike SOS1 mutations, however, those in SOS2 are restricted to the DH domain.
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| 2. |
- Flex, Elisabetta, et al.
(författare)
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Activating mutations in RRAS underlie a phenotype within the RASopathy spectrum and contribute to leukaemogenesis
- 2014
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 23:16, s. 4315-4327
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Tidskriftsartikel (refereegranskat)abstract
- RASopathies, a family of disorders characterized by cardiac defects, defective growth, facial dysmorphism, variable cognitive deficits and predisposition to certain malignancies, are caused by constitutional dysregulation of RAS signalling predominantly through the RAF/MEK/ERK (MAPK) cascade. We report on two germline mutations (p.Gly39dup and p.Val55Met) in RRAS, a gene encoding a small monomeric GTPase controlling cell adhesion, spreading and migration, underlying a rare (2 subjects among 504 individuals analysed) and variable phenotype with features partially overlapping Noonan syndrome, the most common RASopathy. We also identified somatic RRAS mutations (p.Gly39dup and p.Gln87Leu) in 2 of 110 cases of non-syndromic juvenile myelomonocytic leukaemia, a childhood myeloproliferative/myelodysplastic disease caused by upregulated RAS signalling, defining an atypical form of this haematological disorder rapidly progressing to acute myeloid leukaemia. Two of the three identified mutations affected known oncogenic hotspots of RAS genes and conferred variably enhanced RRAS function and stimulus-dependent MAPK activation. Expression of an RRAS mutant homolog in Caenorhabditis elegans enhanced RAS signalling and engendered protruding vulva, a phenotype previously linked to the RASopathy-causing SHOC2(S2G) mutant. Overall, these findings provide evidence of a functional link between RRAS and MAPK signalling and reveal an unpredicted role of enhanced RRAS function in human disease.
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| 3. |
- Nanni, Mirco, et al.
(författare)
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Give more data, awareness and control to individual citizens, and they will help COVID-19 containment
- 2020
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Ingår i: Transactions on Data Privacy. - : Institut d'Investigació en Intel·ligència Artificial. - 1888-5063 .- 2013-1631. ; 23, s. 1-6
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Tidskriftsartikel (refereegranskat)abstract
- The rapid dynamics of COVID-19 calls for quick and effective tracking of virus transmission chains and early detection of outbreaks, especially in the "phase 2" of the pandemic, when lockdown and other restriction measures are progressively withdrawn, in order to avoid or minimize contagion resurgence. For this purpose, contact-tracing apps are being proposed for large scale adoption by many countries. A centralized approach, where data sensed by the app are all sent to a nation-wide server, raises concerns about citizens' privacy and needlessly strong digital surveillance, thus alerting us to the need to minimize personal data collection and avoiding location tracking. We advocate the conceptual advantage of a decentralized approach, where both contact and location data are collected exclusively in individual citizens' "personal data stores", to be shared separately and selectively (e.g., with a backend system, but possibly also with other citizens), voluntarily, only when the citizen has tested positive for COVID-19, and with a privacy preserving level of granularity. This approach better protects the personal sphere of citizens and affords multiple benefits: it allows for detailed information gathering for infected people in a privacy-preserving fashion; and, in turn this enables both contact tracing, and, the early detection of outbreak hotspots on more finely-granulated geographic scale. The decentralized approach is also scalable to large populations, in that only the data of positive patients need be handled at a central level. Our recommendation is two-fold. First to extend existing decentralized architectures with a light touch, in order to manage the collection of location data locally on the device, and allowthe user to share spatio-temporal aggregates - if and when they want and for specific aims - with health authorities, for instance. Second, we favour a longerterm pursuit of realizing a Personal Data Store vision, giving users the opportunity to contribute to collective good in the measure they want, enhancing self-awareness, and cultivating collective efforts for rebuilding society.
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| 4. |
- Lepri, Gemma, et al.
(författare)
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Systemic sclerosis and primary biliary cholangitis : Longitudinal data to determine the outcomes
- 2023
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Ingår i: Journal of Scleroderma and Related Disorders. - 2397-1983. ; 8:3, s. 210-220
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Tidskriftsartikel (refereegranskat)abstract
- Background: Several studies described the cross-sectional characteristics of systemic sclerosis patients and coexisting primary biliary cholangitis, but longitudinal prognostic data are lacking. Aims: To describe the systemic sclerosis–primary biliary cholangitis phenotype, including baseline characteristics and outcomes. Methods: We performed a multicentre the European Scleroderma Trials and Research Group study of systemic sclerosis patients with primary biliary cholangitis or with primary biliary cholangitis–specific antibodies, matched with systemic sclerosis controls free from hepatobiliary involvement matched for disease duration and cutaneous subset. Data were recorded at baseline and at the last available visit. Results: A total of 261 patients were enrolled (115 primary biliary cholangitis–systemic sclerosis, 161 systemic sclerosis). At baseline, systemic sclerosis–primary biliary cholangitis patients had a higher prevalence of anti-centromere antibodies (p = 0.0023) and a lower prevalence of complete absence of digital ulcers. The milder vascular involvement was confirmed at follow-up when crucial differences emerged in the percentage of patients experiencing digital ulcers; a significantly higher number of patients who never experienced digital ulcers were observed among primary biliary cholangitis–systemic sclerosis patients (p = 0.0015). Moreover, a greater incidence of pulmonary arterial hypertension (p < 0.001) and of conduction blocks (p = 0.0256) was observed in systemic sclerosis patients without primary biliary cholangitis. Patients with primary biliary cholangitis had higher levels of liver enzymes at baseline than systemic sclerosis patients; a significant decrease in liver enzymes was observed at follow-up. Out of 18 patients with cholangitis, one received a liver transplant at follow-up. Conclusion: Our data show that systemic sclerosis–primary biliary cholangitis exhibit a mild systemic sclerosis and primary biliary cholangitis phenotype with outcomes being in general favourable.
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