Heterozygosity for loss-of-function variants in LZTR1 is associated with isolated multiple café-au-lait macules.

Purpose: Pathogenic LZTR1 variants cause schwannomatosis and dominant/recessive Noonan syndrome (NS). We aim to establish an association between heterozygous loss-of-function LZTR1 alleles and isolated multiple café-au-lait macules (CaLMs).

Methods: A total of 849 unrelated participants with multiple CaLMs, lacking pathogenic/likely pathogenic NF1 and SPRED1 variants, underwent RASopathy gene panel sequencing.

Defining the variant-phenotype correlation in patients affected by Noonan syndrome with the RAF1:c.770C>T p.(Ser257Leu) variant.

Hypertrophic cardiomyopathy (HCM) is the major contributor to morbidity and mortality in Noonan syndrome (NS). Gain-of-function variants in RAF1 are associated with high prevalence of HCM. Among these, NM_002880.

Clinical variability of neurofibromatosis 1: A modifying role of cooccurring PTPN11 variants and atypical brain MRI findings.

Neurofibromatosis 1 (NF1) is a disorder characterized by variable expressivity caused by loss-of-function variants in NF1, encoding neurofibromin, a protein negatively controlling RAS signaling. We evaluated whether concurrent variation in proteins functionally linked to neurofibromin contribute to the variable expressivity of NF1. Parallel sequencing of a RASopathy gene panel in 138 individuals with molecularly confirmed clinical diagnosis of NF1 identified missense variants in PTPN11, encoding SHP2, a positive regulator of RAS signaling, in four subjects from three unrelated families.

When to test fetuses for RASopathies? Proposition from a systematic analysis of 352 multicenter cases and a postnatal cohort.

Purpose: Recent studies have identified suggestive prenatal features of RASopathies (e.g., increased nuchal translucency [NT], cystic hygroma [CH], hydrops, effusions, congenital heart diseases [CHD], polyhydramnios, renal anomalies).

Early-onset malignant phyllodes breast tumor in a patient with germline pathogenic variants in NF1 and BRCA1 genes.

We present a 24-year-old female patient affected by neurofibromatosis type 1 (NF1) who developed a malignant phyllodes tumor of the breast. The molecular studies showed that the patient carried a heterozygous inactivating deleterious variant in BRCA1 inherited from the father associated with a germline de novo pathogenic alteration in NF1; the tumor presented a biallelic inactivation of both genes. Therefore, tumor analyses helped to establish that the germline NF1 and BRCA1 variants were in cis on the paternal chromosome.

Isoform-specific NF1 mRNA levels correlate with disease severity in Neurofibromatosis type 1.

Background: Neurofibromatosis type 1 (NF1) is characterized by an extreme clinical variability both within and between families that cannot be explained solely by the nature of the pathogenic NF1 gene mutations. A proposed model hypothesizes that variation in the levels of protein isoforms generated via alternative transcript processing acts as modifier and contributes to phenotypic variability.

Results: Here we used real-time quantitative PCR to investigate the levels of two major NF1 mRNA isoforms encoding proteins differing in their ability to control RAS signaling (isoforms I and II) in the peripheral blood leukocytes of 138 clinically well-characterized NF1 patients and 138 aged-matched healthy controls.

Transplantation of clinical-grade human neural stem cells reduces neuroinflammation, prolongs survival and delays disease progression in the SOD1 rats.

Stem cells are emerging as a therapeutic option for incurable diseases, such as Amyotrophic Lateral Sclerosis (ALS). However, critical issues are related to their origin as well as to the need to deepen our knowledge of the therapeutic actions exerted by these cells. Here, we investigate the therapeutic potential of clinical-grade human neural stem cells (hNSCs) that have been successfully used in a recently concluded phase I clinical trial for ALS patients (NCT01640067).

Activating Mutations Affecting the Dbl Homology Domain of SOS2 Cause Noonan Syndrome.

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.

Noonan syndrome-like disorder with loose anagen hair: a second case with neuroblastoma.

Noonan-like syndrome with loose anagen hair (NSLH), also known as Mazzanti syndrome, is a RASopathy characterized by craniofacial features resembling Noonan syndrome, cardiac defects, cognitive deficits and behavioral issues, reduced growth generally associated with GH deficit, darkly pigmented skin, and an unique combination of ectodermal anomalies. Virtually all cases of NSLH are caused by an invariant and functionally unique mutation in SHOC2 (c.4A>G, p.

p.Arg1809Cys substitution in neurofibromin is associated with a distinctive NF1 phenotype without neurofibromas.

Analysis of 786 NF1 mutation-positive subjects with clinical diagnosis of neurofibromatosis type 1 (NF1) allowed to identify the heterozygous c.5425C>T missense variant (p.Arg1809Cys) in six (0.

Search of somatic GATA4 and NKX2.5 gene mutations in sporadic septal heart defects.

High prevalence of somatic mutations in the cardiac transcription factor genes NKX2.5 and GATA4 have been reported in the affected cardiovascular tissue of patients with isolated cardiac septal defects, suggesting a role of somatic mutations in the pathogenesis of these congenital heart defects (CHDs). However, all somatic mutations have been identified in DNA extracted from an archive of formalin-fixed cardiac tissues.

Natural variation of model mutant phenotypes in Ciona intestinalis.

Background: The study of ascidians (Chordata, Tunicata) has made a considerable contribution to our understanding of the origin and evolution of basal chordates. To provide further information to support forward genetics in Ciona intestinalis, we used a combination of natural variation and neutral population genetics as an approach for the systematic identification of new mutations. In addition to the significance of developmental variation for phenotype-driven studies, this approach can encompass important implications in evolutionary and population biology.