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Neurofibromatosis type 1 (NF1) is a neurocutaneous syndrome caused by pathogenic variants in the NF1 gene, encoding a multidomain inhibitor of Ras activity. Thus, NF1 is considered a RASopathy and drugs targeting the RAS/mitogen-activated protein kinase (MAPK) pathway, such as the MAP kinase (MEK) 1/2 inhibitor Selumetinib, are promising therapeutic options to treat NF1-associated tumors, especially plexiform neurofibromas and optic way gliomas. However, surgical treatment is often required for NF1-related cerebrovascular manifestations, such as moyamoya syndrome (MMS). We report a case of an 8-year-old patient receiving Selumetinib at the dose of 25 mg/m2 orally 2 times a day as a treatment for many plexiform neurofibromas. He suffered from two close strokes and brain MRI revealed a severe cerebral vasculopathy consistent with MMS, with marked stenosis of both the internal carotid arteries. A two-step surgical revascularization procedure was performed, consisting of a direct by-pass with an encephalo-mio-synangiosis (EMS) followed by encephalo-duro-arterio-synangiosis (EDAS). Surprisingly, despite the surgical technical success, follow-up MRI revealed lack of the expected revascularization. Selumetinib is a powerful therapeutic option in the treatment of severe NF1-related tumors. However, our findings suggest that this drug may interfere with cerebral neovascularization in patients with MMS requiring surgical revascularization. This is supported by the crucial role of the Vascular-Endothelial Growth Factor (VEGF), whose signaling pathway involve MAPK, as promoter of the neovascularization. Our observations suggest to adopt an imaging surveillance strategy to prevent unfavorable surgical outcome in patients with NF1-associated MMS receiving Selumetinib, and that priority should be given to surgical revascularization.

BackgroundEvans syndrome (ES) is a rare disorder classically defined as the simultaneous or sequential presence of autoimmune haemolytic anaemia and immune thrombocytopenia, but it has also been described as the presence of at least two autoimmune cytopenias. Recent reports have shown that ES is often a manifestation of an underlying inborn error of immunity (IEI) that can benefit from specific treatments.AimsThe aim of this study is to investigate the clinical and immunological characteristics and the underlying genetic background of a single-centre cohort of patients with ES.MethodsData were obtained from a retrospective chart review of patients with a diagnosis of ES followed in our centre. Genetic studies were performed with NGS analysis of 315 genes related to both haematological and immunological disorders, in particular IEI.ResultsBetween 1985 and 2020, 40 patients (23 men, 17 women) with a median age at onset of 6 years (range 0–16) were studied. ES was concomitant and sequential in 18 (45%) and 22 (55%) patients, respectively. Nine of the 40 (8%) patients had a positive family history of autoimmunity. Other abnormal immunological features and signs of lymphoproliferation were present in 24/40 (60%) and 27/40 (67%) of cases, respectively. Seventeen out of 40 (42%) children fit the ALPS diagnostic criteria. The remaining 21 (42%) and 2 (5%) were classified as having an ALPS-like and an idiopathic disease, respectively. Eighteen patients (45%) were found to have an underlying genetic defect on genes FAS, CASP10, TNFSF13B, LRBA, CTLA4, STAT3, IKBGK, CARD11, ADA2, and LIG4. No significant differences were noted between patients with or without variant and between subjects with classical ES and the ones with other forms of multilineage cytopenias.ConclusionsThis study shows that nearly half of patients with ES have a genetic background being in most cases secondary to IEI, and therefore, a molecular evaluation should be offered to all patients.

The role of muscle biopsy in the diagnostic workup of floppy infants is controversial. Muscle sampling is invasive, and often, results are not specific. The rapid expansion of genetic approach has made the muscle histopathology analysis less crucial. This study aims to assess the role and efficacy of muscle histopathology in the diagnostic algorithm of hypotonia in early infancy through a retrospective analysis of 197 infants who underwent muscle biopsy in their first 18 months of life. Data analysis revealed that 92/197 (46.7%) of muscle biopsies were non-specific (80) or normal (12), not allowing a specific diagnosis. In 41/197 (20.8%) cases, biopsy suggested a metabolic or mitochondrial myopathy, while in 23/197 cases (11.7%), we found evidence of muscular dystrophy. In 19/197 cases (9.7%), histopathology characteristics of a congenital myopathy were reported. In 22/197 cases (11.7%), the histopathological study indicated presence of a neurogenic damage. Overall, 46 diagnoses were then achieved by oriented genetic tests. Muscle biopsy results were consistent with genetic results in 90% of cases. Diagnostic algorithms for the diagnosis of a floppy infant are largely missing. Muscle biopsy alone can lead to a diagnosis, help the clinician in the choice of a genetic test, or even modify a diagnosis made previously.

Dystrophinopathies are inherited diseases caused by mutations in the dystrophin (DMD) gene for which testing is mandatory for genetic diagnosis, reproductive choices and eligibility for personalized trials. We genotyped the DMD gene in our Italian cohort of 1902 patients (BMD n = 740, 39%; DMD n =1162, 61%) within a nationwide study involving 11 diagnostic centers in a 10-year window (2008–2017). In DMD patients, we found deletions in 57%, duplications in 11% and small mutations in 32%. In BMD, we found deletions in 78%, duplications in 9% and small mutations in 13%. In BMD, there are a higher number of deletions, and small mutations are more frequent than duplications. Among small mutations that are generally frequent in both phenotypes, 44% of DMD and 36% of BMD are nonsense, thus, eligible for stop codon read-through therapy; 63% of all out-of-frame deletions are eligible for single exon skipping. Patients were also assigned to Italian regions and showed interesting regional differences in mutation distribution. The full genetic characterization in this large, nationwide cohort has allowed us to draw several correlations between DMD/BMD genotype landscapes and mutation frequency, mutation types, mutation locations along the gene, exon/intron architecture, and relevant protein domain, with effects on population genetic characteristics and new personalized therapies.