Neurofibromatosis 1 and neurofibromatosis 2: a twenty first century perspective

Neurofibromatosis type 1 as a model system to study molecular mechanisms of autism spectrum disorder symptoms

Neurofibromatosis type 1 (NF1) is monogenic neurodevelopmental disorder caused by mutation of NF1 gene, which leads to increased susceptibility to various tumors formations. Additionally, majority of patients with NF1 are experience high incidence of cognitive deficits. Particularly, we review the growing number of reports demonstrated a higher incidence of autism spectrum disorder (ASD) in individuals with NF1. In this review we also discuss face validity of preclinical Nf1 mouse models. Then we describe discoveries from these animal models that have uncovered the deficiencies in the regulation of Ras and other intracellular pathways as critical mechanisms underlying the Nf1 cognitive problems. We also summarize and interpret recent preclinical and clinical studies that point toward potential pharmacological therapies for NF1 patients.

Spectrum of gastrointestinal lesions of neurofibromatosis type 1: a pictorial review

Abstract

Neurofibromatosis type 1 (NF1) is one of the most common genetic disorders. Gastrointestinal manifestations of NF-1 are seldom thought of in routine clinical practice and might thus be significantly under-recognised. Their heterogeneous spectrum ranges from localised microscopic proliferative lesions to grossly recognizable mass-forming neurofibromas, neuroendocrine and gastrointestinal stromal tumours (GIST). The aim of this study is discussing the imaging evaluation and characterisation of the abdomen lesions in patients with NF1.

Teaching Points

• Neurofibromatosis type (NF-1) is one of the most common single gene disorders.

• Every organ system can be involved and intra-abdominal manifestations are underestimated.

• The NF1 abdominal manifestations comprehend five categories of tumours.

• Neurogenic tumours including with neurofibromas are the most common type.

• Early diagnosis of abdominal manifestations of NF-1 based on imaging patterns is necessary for appropriate treatment to avoid serious organic complications related to tumour mass.

Neuropsychological profile in Italian children with neurofibromatosis type 1 (NF1) and their relationships with neuroradiological data: Preliminary results

BACKGROUND

Neurofibromatosis type 1 is a genetic disorder associated with cognitive deficits, learning disabilities and behavioral problems. These domains appear to have a still controversial debated association with local areas of T2-hyperintensities on MRI images, called unidentified bright objects (UBOs).

METHODS

A cohort of 36 children (aged 7-11 years) included consecutively, underwent neuropsychological and behavioral assessment to determine their cognitive and neuropsychological profile, and the frequency of specific learning disabilities. MRI examination was used to determine the impact of UBOs' presence, number, and location on the cognitive, neuropsychological and behavioral profile, and also the presence of optic glioma.

RESULTS

The mean full intelligence quotient was 104.6; only one child had mild intellectual disability. Forty one percent of children had a diagnosis of specific learning disabilities and reading was mainly involved. Twenty per cent had attention problems. All children had normal scores in visuo-motor and visuo-perceptual tests. UBOs were present in 94.0% of the MRI examinations. Two children had optic glioma. Children with UBOs in a specific location and children with UBOs elsewhere were statistically compared, no one of the location seemed to have an impact on general cognition measured with full intelligence quotient. The thalamus was associated with problems in calculation and striatum with behavioral problems. An inverse relationship between the number of UBOs and the full intelligence quotient was present, but without a statistical significance.

CONCLUSIONS

In this study, the specific location of UBOs did not seem to influence the general cognitive profile and also the relationship between their number and the full intelligence quotient was not significant; these results are still controversial in literature. Finally, the presence of UBOs in the thalamus and striatum may represent a neuroradiological pattern that influences performances in calculation and behavior respectively in children with Neurofibromatosis type 1.

Quick and sustained clinical response to MEK inhibitor I in a NF1 patient with neurofibromas

Neurofibromatosis 1 (NF1) is an autosomal dominant tumour predisposition disorder with a birth incidence of about 1 in 2,700 and prevalence of 1 in 4,560. The NF1 gene codes for an ubiquitous protein: neurofibromin. Neurofibromin interacts with the proto-oncogene RAS to suppress tumour formation. Individuals with germline inactivation of the NF1 gene have a propensity to develop both benign and malignant tumours.

We report the case of a 12-year-old child with NF1, diagnosed at the age of 15 months, for whom the clinical course has been marked by the appearance of multiple cutaneous and paraspinal neurofibromas responsible for impaired walking, motor deficiency and pain. A treatment with an MEK inhibitor, trametinib, was initiated and led to a quick and sustained clinical response.

CRISPR/Cas9 editing of Nf1 gene identifies CRMP2 as a therapeutic target in neurofibromatosis type 1-related pain that is reversed by (S)-Lacosamide

Neurofibromatosis type 1 (NF1) is a rare autosomal dominant disease linked to mutations of the Nf1 gene. Patients with NF1 commonly experience severe pain. Studies on mice with Nf1 haploinsufficiency have been instructive in identifying sensitization of ion channels as a possible cause underlying the heightened pain suffered by patients with NF1. However, behavioral assessments of Nf1 mice have led to uncertain conclusions about the potential causal role of Nf1 in pain. We used the clustered regularly interspaced short palindromic repeats (CRISPR)-associated 9 (CRISPR/Cas9) genome editing system to create and mechanistically characterize a novel rat model of NF1-related pain. Targeted intrathecal delivery of guide RNA/Cas9 nuclease plasmid in combination with a cationic polymer was used to generate allele-specific C-terminal truncation of neurofibromin, the protein encoded by the Nf1 gene. Rats with truncation of neurofibromin, showed increases in voltage-gated calcium (specifically N-type or CaV2.2) and voltage-gated sodium (particularly tetrodotoxin-sensitive) currents in dorsal root ganglion neurons. These gains-of-function resulted in increased nociceptor excitability and behavioral hyperalgesia. The cytosolic regulatory protein collapsin response mediator protein 2 (CRMP2) regulates activity of these channels, and also binds to the targeted C-terminus of neurofibromin in a tripartite complex, suggesting a possible mechanism underlying NF1 pain. Prevention of CRMP2 phosphorylation with (S)-lacosamide resulted in normalization of channel current densities, excitability, as well as of hyperalgesia following CRISPR/Cas9 truncation of neurofibromin. These studies reveal the protein partners that drive NF1 pain and suggest that CRMP2 is a key target for therapeutic intervention.

Gliosarcoma in a young patient with neurofibromatosis type 1. Case report

Introducción. La neurofibromatosis tipo 1 (NF1) es una condición autosómica dominante que presenta una expresividad fenotípica variable, con manifestaciones que van desde lesiones cutáneas hasta compromiso funcional. Se manifiesta clínicamente durante la infancia y la adolescencia; su gen codifica una proteína, la neurofibromina, que actúa como un supresor tumoral en condiciones normales regulando, a su vez, otra proteína que estimula el crecimiento y proliferación celular. En caso de alteración se podrían presentar diferentes procesos tumorales como el que se evidencia en un reducido número de casos. Presentación de caso. Paciente masculino de 20 años con NF1, quien presentaba lesiones cutáneas como manchas color café con leche y desarrolló un glioblastoma, lo cual sucede de manera infrecuente. Discusión. Para obtener el diagnóstico confirmado se incluyen métodos de inmunohistoquímica que contribuyen en gran medida al pronóstico puesto que la mediana de supervivencia global de los pacientes de glioblastoma es mayor en pacientes con NF1 que aquellos sin dicha entidad patológica. Conclusión. El diagnóstico temprano de las lesiones favorece un manejo a tiempo de la NF1. Estos pacientes requieren un manejo integral e interdisciplinar para favorecer su rehabilitación total.

Gastrointestinal Symptoms in Children and Adolescents With Neurofibromatosis Type 1

OBJECTIVES

Neurofibromatosis type 1 (NF1) is a complex genetic disorder characterized by symptoms of the skin and nervous system. A previous study indicated that constipation is common in children with NF1. The aim of the present study was to investigate the phenotype and prevalence of gastrointestinal (GI) symptoms in a population of 4 to 17-year-olds with NF1 compared with their unaffected siblings.

METHODS

GI symptoms were assessed with a web-based, parent or self-administered, validated, Rome III diagnostic questionnaire. Participants were recruited from 1 of 2 Danish National Centers of Expertise for NF1. Logistic regression was used to estimate the prevalence of functional dyspepsia, irritable bowel syndrome (IBS), and constipation in each group and the groups were compared using odds ratio (OR).

RESULTS

We compared 102 NF1 patients (median age 10.3 years) and 46 of their unaffected siblings (median age 10 years). The overall likelihood of having GI symptoms usually attributed to either functional dyspepsia, IBS, or constipation was 30.4% in patients versus 10.9% in siblings, OR 3.58 (95% confidence interval 1.30 to 9.79). The prevalence of constipation was 22.5% in patients and 4.3% in siblings, OR 6.41 (95% confidence interval 1.45 to 28.24). The use of laxatives was 16% (n = 16) in patients and 2% (n = 1) in siblings.

CONCLUSIONS

Overall, GI symptoms attributed to functional dyspepsia, IBS or constipation are more common in 4 to 17-year-olds with NF1 when compared with their unaffected siblings. The high prevalence indicates that GI dysfunction in NF1 is not functional but may be part of the underlying NF1 disorder.

Investigation of retinal nerve fiber layer thickness and ganglion cell layer-inner plexiform layer thickness in patients with optic pathway gliomas

PURPOSE

This study aimed to compare the optical coherence tomography (OCT) findings of optic pathway glioma (OPG) patients (sporadic or secondary to neurofibromatosis type 1, NF1) with NF1 without OPG patients and healthy controls.

METHODS

This was a prospective, case-control study in which 27 patients (13 with OPGs and 14 with NF1 without OPGs) and 13 control subjects were included. The retinal nerve fiber layer (RNFL) thickness, macular thickness, and ganglion cell layer-inner plexiform layer (GCL-IPL) thickness findings measured using OCT and the results were compared between the groups.

RESULTS

The macular thickness was significantly lower in the OPG group than in the control group and the NF1 patients without OPGs group (p < 0.001). The GCL-IPL thickness was lower in OPG group than in the control group and the NF1 patients without OPG group (p < 0.001). The RNFL thickness was lower in the OPG group than in the control group and the NF1 patients without OPG group (p < 0.001). There was a statistically significantly negative correlation between the visual acuity (log of the minimum angle of resolution, logMAR) and all the other parameters (macular, RNFL, and GCL-IPL thicknesses). All the parameters were found to positively correlate with each other.

CONCLUSIONS

OCT measurements (macular thickness, RNFL, and GCL-IPL thicknesses) can be used to monitor the disease in those patients with suspected OPGs; however, this should be verified with a larger case series.

Restoring functional neurofibromin by protein transduction

In Neurofibromatosis 1 (NF1) germ line loss of function mutations result in reduction of cellular neurofibromin content (NF1+/-, NF1 haploinsufficiency). The Ras-GAP neurofibromin is a very large cytoplasmic protein (2818 AA, 319 kDa) involved in the RAS-MAPK pathway. Aside from regulation of proliferation, it is involved in mechanosensoric of cells. We investigated neurofibromin replacement in cultured human fibroblasts showing reduced amount of neurofibromin. Full length neurofibromin was produced recombinantly in insect cells and purified. Protein transduction into cultured fibroblasts was performed employing cell penetrating peptides along with photochemical internalization. This combination of transduction strategies ensures the intracellular uptake and the translocation to the cytoplasm of neurofibromin. The transduced neurofibromin is functional, indicated by functional rescue of reduced mechanosensoric blindness and reduced RasGAP activity in cultured fibroblasts of NF1 patients or normal fibroblasts treated by NF1 siRNA. Our study shows that recombinant neurofibromin is able to revert cellular effects of NF1 haploinsuffiency in vitro, indicating a use of protein transduction into cells as a potential treatment strategy for the monogenic disease NF1.

CRMP2-Neurofibromin Interface Drives NF1-related Pain

An understudied symptom of the genetic disorder Neurofibromatosis type 1 (NF1) is chronic idiopathic pain. We used targeted editing of Nf1 in rats to provide direct evidence of a causal relationship between neurofibromin, the protein product of the Nf1 gene, and pain responses. Our study data identified a protein-interaction network with collapsin response meditator protein 2 (CRMP2) as a node and neurofibromin, syntaxin 1A, and the N-type voltage-gated calcium (CaV2.2) channel as interaction edges. Neurofibromin uncouples CRMP2 from syntaxin 1A. Upon loss/mutation of neurofibromin, as seen in patients with NF1, the CRMP2/Neurofibromin interaction is uncoupled, which frees CRMP2 to interact with both syntaxin 1A and CaV2.2, culminating in increased release of the pro-nociceptive neurotransmitter calcitonin gene-related peptide (CGRP). Our work also identified the CRMP2-derived peptide CNRP1, which uncoupled CRMP2's interactions with neurofibromin, syntaxin 1A, as well as CaV2.2. Here, we tested if CRISPR/Cas9-mediated editing of the Nf1 gene, which leads to functional remodeling of peripheral nociceptors through effects on the tetrodotoxin-sensitive (TTX-S) Na⁺ voltage-gated sodium channel (NaV1.7) and CaV2.2, could be affected using CNRP1, a peptide designed to target the CRMP2-neurofibromin interface. The data presented here shows that disrupting the CRMP2-neurofibromin interface is sufficient to reverse the dysregulations of voltage-gated ion channels and neurotransmitter release elicited by Nf1 gene editing. As a consequence of these effects, the CNRP1 peptide reversed hyperalgesia to thermal stimulation of the hindpaw observed in Nf1-edited rats. Our findings support future pharmacological targeting of the CRMP2/neurofibromin interface for NF1-related pain relief.

CT and MRI of superficial solid tumors

Superficial solid masses are common conditions in clinical practice, however, some of which can be easily diagnosed and others would be difficult. Although imaging of superficial masses is not always characteristic, it would be helpful to give a definitive diagnosis or narrow a differential diagnosis. Crossing-section imaging can depicture the masses directly, find some pathognomonic signs and demonstrate their relationship with adjacent structures, which can provide decision support for clinician's reference. Computed tomography (CT) can be used to detect calcifications and bone erosion which could not be seen on radiographs. Magnetic resonance imaging (MRI) is the preferred way for evaluating soft tissue lesions and provides information on hemorrhage, necrosis, edema, cystic and myxoid degeneration, and fibrosis. Other advantages of MRI are its superior soft tissue resolution and any profile imaging, which can aid the assessment of extension and adjacent infiltration. Positron emission tomography (PET)/CT and PET/MRI have been increasingly used in bone and soft tissue sarcomas and provides advantages in the initial tumor staging, tumor grading, therapy assessment, and recurrence detection. Therefore, imaging examination can play an important role in treatment decision making for superficial solid tumors. Here we review the important conditions presenting as superficial mass and show the imaging of typical cases diagnosed in our hospital.

Large penile plexiform neurofibroma in an 11-year old boy

Background

Neurofibromatosis is a genetically inherited disorder of the nervous system (brain and spinal cord) which mainly affects the development of nerve (neural) cell tissues, causing tumors (neurofibromas) to develop on nerves. It is the most common single gene disorder of the nervous system and inheritance is through autosomal dominance. They are usually classified into types 1 and 2, the type 1 is the commoner type and also known as superficial neurofibroma. Plexiform neurofibromas are the next most common type of tumor in individuals with type 1 neurofibroma. Plexiform neurofibromas are histologically benign tumors that are made up of a variety of cell types including neuronal axons, Schwann cells, fibroblasts, mast cells, macrophages, perineural cells and extracellular matrix materials such as collagen. They can occur in any part of the body and can grow throughout the person's lifetime, often becoming disfiguring, disabling or deadly via compression of vital structures or conversion to a malignant sarcoma or malignant peripheral nerve sheath turmor. The aim of this report is to present a large penile plexiform neurofibroma which required extensive dissection for complete excision and reconstruction of the phallus and glans penis.

Objectives

To present a huge penile plexiform neurofibroma and the mode of surgical treatment.

Methods

The huge penile plexiform neurofibroma was completely excised and the penile defect resulting from the excision was repaired.

Conclusion

Plexiform neurofibromas are congenital tumors of peripheral nerve sheaths which may also develop near nerve roots deep within the body. They are usually benign but carry a malignant potential in 5-10% of patients. Plexiform neurofibromas are commoner in the face, chest and limbs but the index case occurred on the penile shaft.

Uncovering Hereditary Tumor Syndromes: Emerging Role of Surgical Pathology

With the increased use of modern next generation sequencing technologies in routine molecular pathology practice, the proportion of cancer cases with a definite or probable hereditary background seems to be steadily increasing. Currently, it is assumed that ≥10% of all malignancies develop in the setting of germline predisposition. Diagnosis and recognition of cancer predisposition syndromes relies not rarely on distinctive histopathological features that proved to be highly valuable and reproducible in uncovering those diseases that would otherwise have gone undetected by clinicians as being hereditary in nature. This is especially true in case of new mutations without suspicious family history. Example of such entities are fumarate hydratase-deficient renal cell carcinoma (RCC), succinate dehydrogenase-deficient RCC, hereditary gastrointestinal stromal tumor syndromes and many other diseases. It is remarkable that many of these inherited cancer syndromes do present as unifocal disease with highly variable age of onset so that many of them are misinterpreted as sporadic on clinical grounds. Availability of specialized cancer screening programs and disease-specific follow-up schemes for several hereditary cancer syndromes encourages the recognition of such disorders, so that "at risk patients" can be enrolled in such programs for early detection and timely intervention/ treatment of these malignancies which are in the majority of cases aggressive. In several conditions, as in familial adenomatous polyposis coli (FAP), well established prophylactic surgical interventions may be adopted to prevent the disease manifestations, highlighting the importance of the timely recognition of these potentially life-limiting neoplasms. In this review, the clinicopathological, demographic and histological features that are considered highly suggestive of a hereditary basis of "a neoplasm under consideration" are highlighted and discussed briefly. The details of some of these entities are in addition dealt with in reviews devoted to them in this special issue.

Intraductal papillary bile duct adenocarcinoma and gastrointestinal stromal tumor in a case of neurofibromatosis type 1

We report our experience with a synchronous case of gastrointestinal stromal tumor (GIST) and intraductal papillary neoplasm of the bile duct (IPNB) in an elderly woman with neurofibromatosis type 1 (NF-1). A 72-year-old woman presented with a 2-mo history of right upper abdominal pain unrelated to diet and indigestion. Fourteen years earlier, she had been diagnosed with NF-1, which manifested as café au lait spots and multiple nodules on the skin. Computed tomography (CT) revealed a multilocular low-density mass with septation, and mural nodules in the right hepatic lobe, as well as a 1.7-cm-sized well-demarcated enhancing mass in the third portion of the duodenum. The patient subsequently underwent right hepatectomy and duodenal wedge resection. We present here the first report of a case involving a synchronous IPNB and GIST in a patient with NF-1. Our findings demonstrate the possibility of various tumors in NF-1 patients and the importance of diagnosis at an early stage

Congenital anomalies in neurofibromatosis 1: a retrospective register-based total population study

Background

Neurofibromatosis type 1 (NF1) is a dominantly inherited Rasopathy caused by mutations in the NF1 gene on chromosome 17. NF1 has been connected to congenital anomalies, e.g., in the skeletal and cardiovascular systems, but the overall incidence of anomalies is unknown. In this retrospective register-based total population study conducted in Finland, the congenital anomalies in NF1 were evaluated.

Methods

One thousand four hundred ten patients with NF1 were identified by searching the medical records related to inpatient and outpatient hospital visits of patients with an associated diagnosis for NF1 in 1987–2011. Each diagnosis was confirmed by a thorough review of the medical records. Ten non-NF1 control persons per NF1 patient were collected from the Population Register Centre. NF1 patients and controls were linked to the Medical Birth Register and the Register of Congenital Malformations. Odds ratios (OR) and 95% confidence intervals (95% CI) for major congenital anomalies (MCA) were calculated.

Results

The OR for at least one MCA among NF1 children was almost threefold (adjusted OR 2.78, 95% CI 1.71–4.54) compared to controls matched for age, sex and municipality. NF1 children had a significantly increased risk of congenital anomalies in the circulatory (adjusted OR 3.35, 95% CI 1.64–6.83), urinary (adjusted OR 4.26, 95% CI 1.36–13.35) and musculoskeletal (adjusted OR 2.77, 95% CI 1.09–7.02) systems. Also, anomalies of the eye, ear, head and neck were more common among NF1 children than controls (adjusted OR 4.66, 95% CI 1.42–15.31). Non-NF1 children of mothers with NF1 did not have more anomalies than controls (adjusted OR 0.53, 95% CI 0.13–2.21).

Conclusions

Children with NF1 have more MCAs than controls and close follow-up during pregnancy and the neonatal period is required if the mother or father has NF1. Non-NF1 children of mothers with NF1 do not have an increased risk for anomalies.

Tumor targeted delivery of doxorubicin in malignant peripheral nerve sheath tumors

Peripheral nerve sheath tumors are benign tumors that have the potential to transform into malignant peripheral nerve sheath tumors (MPNSTs). Interleukin-13 receptor alpha 2 (IL13Rα2) is a cancer associated receptor expressed in glioblastoma and other invasive cancers. We analyzed IL13Rα2 expression in several MPNST cell lines including the STS26T cell line, as well as in several peripheral nerve sheath tumors to utilize the IL13Rα2 receptor as a target for therapy. In our studies, we demonstrated the selective expression of IL13Rα2 in several peripheral nerve sheath tumors by immunohistochemistry (IHC) and immunoblots. We established a sciatic nerve MPNST mouse model in NIH III nude mice using a luciferase transfected STS26T MPNST cell line. Similarly, analysis of the mouse sciatic nerves after tumor induction revealed significant expression of IL13Rα2 by IHC when compared to a normal sciatic nerve. IL13 conjugated liposomal doxorubicin was formulated and shown to bind and internalized in the MPNST cell culture model demonstrating cytotoxic effect. Our subsequent in vivo investigation in the STS26T MPNST sciatic nerve tumor model indicated that IL13 conjugated liposomal doxorubicin (IL13LIPDXR) was more effective in inhibiting tumor progression compared to unconjugated liposomal doxorubicin (LIPDXR). This further supports that IL13 receptor targeted nanoliposomes is a potential approach for treating MPNSTs.

Receptor of ghrelin is expressed in cutaneous neurofibromas of individuals with neurofibromatosis 1

BACKGROUND

Multiple cutaneous neurofibromas are a hallmark of neurofibromatosis 1 (NF1). They begin to appear during puberty and increase in number and volume during pregnancy, suggesting a hormonal influence. Ghrelin is a hormone that acts via growth hormone secretagogue receptor (GHS-R), which is overexpressed in many neoplasms and is involved in tumorigenesis. We aimed to investigate GHS-R expression in NF1 cutaneous neurofibromas and its relationship with tumors volume, and patient's age and gender.

RESULTS

Sample comprised 108 cutaneous neurofibromas (55 large and 53 small tumors) from 55 NF1 individuals. GHS-R expression was investigated by immunohistochemistry in tissue micro and macroarrays and quantified using a digital computer-assisted method. All neurofibromas expressed GHS-R, with a percentage of positive cells ranging from 4.9% to 76.1%. Large neurofibromas expressed more GHS-R than the small ones. The percentage of GHS-R-positive cells and intensity of GHS-R expression were positively correlated with neurofibromas volume. GHS-R expression was more common in female gender.

CONCLUSIONS

GHS-R is expressed in cutaneous neurofibromas. Larger neurofibromas have a higher percentage of positive cells and higher GHS-R intensity. Based on our results we speculate that ghrelin may have an action on the tumorigenesis of cutaneous neurofibromas. Future studies are required to understand the role of ghrelin in the pathogenesis of NF1-associated cutaneous neurofibroma.

Tumour stem cells in meningioma: A review

Meningioma is a common intracranial and intraspinal neoplasm accounting for 25-30% of all primary neurological tumours. It is associated with high rates of recurrence especially in higher-grade tumours and lesions located at the skull base. Cancer stem cells are increasingly recognised as the origin of cancer and are attributed to loco-regional recurrence, metastasis and treatment resistance. This review presents the accumulating evidence of the presence of tumour stem cells within meningioma and the stem cell markers being used to characterise this putative primitive population within this common tumour.

Dysregulated gene expressions of MEX3D, FOS and BCL2 in human induced-neuronal (iN) cells from NF1 patients: a pilot study

Direct conversion technique to produce induced-neuronal (iN) cells from human fibroblasts within 2 weeks is expected to discover unknown neuronal phenotypes of neuropsychiatric disorders. Here, we present unique gene expression profiles in iN cells from patients with neurofibromatosis type 1 (NF1), a single-gene multifaceted disorder with comparatively high co-occurrence of autism spectrum disorder (ASD). Microarray-based transcriptomic analysis on iN cells from male healthy controls and male NF1 patients (NF1-iN cells) revealed that 149 genes expressions were significantly different (110 upregulated and 39 downregulated). We validated that mRNA of MEX3D (mex-3 RNA binding family member D) was lower in NF1-iN cells by real-time PCR with 12 sex-mixed samples. In NF1-iN cells on day 14, higher expression of FOS mRNA was observed with lower expression of MEX3D mRNA. Interestingly, BCL2 mRNA was higher in NF1-iN cells on day 5 (early-period) but not on day 14. Our data suggest that aberrant molecular signals due to NF1 mutations may disturb gene expressions, a subset of which defines continuum of the neuronal phenotypes of NF1 with ASD. Further translational studies using induced pluripotent stem (iPS) cell-derived neuronal cells are needed to validate our preliminary findings especially confirming meanings of analysis using early-period iN cells.

Constipation in adults with neurofibromatosis type 1

Background

Neurofibromatosis type 1 (NF1) is an autosomal-dominant disease characterised by symptoms of the skin, eyes, nervous system and bones. A previous study indicated that constipation, large rectal diameters and prolonged colorectal transit times are common in children with NF1. The aim of the present study was to investigate and compare the prevalence of gastrointestinal symptoms in adult patients with NF1 to their unaffected relatives serving as the control group. Patients with NF1 were recruited from one of two Danish National Centres of Expertise for NF1 and their unaffected relatives were invited to participate as controls. Gastrointestinal symptoms were assessed with a web-based, self-administered, validated, Rome® III diagnostic questionnaire. Logistic regression was used to estimate the prevalence of functional dyspepsia, IBS and functional constipation in each group and the groups were compared using their odds ratios.

Results

The response rates for patients and controls were 66.4% and 82.4%, respectively. We compared 175 patients, median age 34.2 (IQR = 20.1) and 91 of their unaffected relatives, median age 42.0 (IQR = 12). The overall likelihood of fulfilling the diagnostic criteria for functional constipation, irritable bowel syndrome or functional dyspepsia was 33.1% among patients vs. 14.3% among controls, (odds ratio (OR): 2.97; 95% CI: 1.56–5.66) and after adjustment for age and gender (OR: 3.06; 95% CI: 1.62–5.79). The likelihood of functional constipation was higher among patients (OR: 3.80; 95% CI: 1.27–11.31), and this was still true after adjustment (OR: 3.49; 95% CI: 1.14–10.64). The likelihood of irritable bowel syndrome (OR: 2.29; 95% CI: 0.98–5.33) was evident after adjustment (OR: 2.46; 95% CI: 1.10–5.47), whereas there was no difference in the likelihood of functional dyspepsia (OR: 2.35; 95% CI: 0.67–8.32) after adjustment (OR:2.25; 95% CI: 0.70–7.17).

Conclusions

Overall, having symptoms usually attributed to either functional dyspepsia, IBS or functional constipation is more common in adults with NF1 compared to unaffected relatives. Of the three, the likelihood of constipation is markedly higher. The high prevalence of constipation indicates that it is not functional but part of the NF1 disorder.

The pregnancy in neurofibromatosis 1: A retrospective register-based total population study

The objective of this retrospective total population study was to form a view of the pregnancies of the patients with neurofibromatosis type 1 (NF1). A cohort of 1,410 Finnish patients with NF1 was acquired by searching NF1-related inpatient and outpatient hospital visits and confirming the diagnoses by reviewing the medical records. Ten matched control persons per patient with NF1 were collected from Population Register Centre. Study persons were linked to data from Medical Birth Register and Care Register for Health Care through the personal identity code. Cesarean deliveries, hypertension/preeclampsia, and placental abruptions were more common among mothers with NF1 with adjusted odds ratios of 2.24 (95%CI 1.63-3.07), 1.96 (95%CI 1.18-3.24), and 13.40 (95%CI 4.26-42.13), respectively. The adjusted mean pregnancy duration was 0.65 (95%CI 0.42-0.88) weeks shorter among the mothers with NF1 than in the control group consisting of non-NF1 mothers giving birth to a non-NF1 child. The pregnancies of non-NF1 mothers giving birth to a NF1 child were 0.43 (95%CI 0.24-0.62) weeks shorter than in the control group. In summary, NF1 of the mother was associated with a shortened pregnancy and increased pregnancy complications. Also, the NF1 of the fetus slightly shortened pregnancy. Since mothers with NF1 are at increased risk for pregnancy complications, careful evaluation of their pregnancies is warranted.

Severe dyspnea in a patient with neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is a genetic disease in which pulmonary complications are rare, but severe, especially pulmonary hypertension (PH). The mechanisms underlying the onset of PH in patients with NF1 are unclear and might be multifactorial. In particular, the frequent presence of pulmonary parenchymal lesions makes etiological diagnosis of PH difficult. We describe here the case of a patient with NF1 admitted to our clinic with dyspnea and right heart failure revealing severe pre-capillary PH. Parenchymal lesions were mild and PH was attributed to pulmonary vascular involvement. Clinical and hemodynamic conditions of the patient improved under pulmonary arterial hypertension-specific combination therapy. This case suggests that treatment of PH due to pulmonary vascular involvement in NF1 may be aligned with recommendations for PAH treatment.

Clinical presentation and prognostic indicators in 100 adults and children with neurofibromatosis 1 associated non-optic pathway brain gliomas

Type 1 Neurofibromatosis (NF1) is a common autosomal dominant condition, with a major impact on the nervous system, eye, bone, and skin, and a predisposition to malignancy. At present it is not possible to predict clinically or on imaging, whether a brain tumour will remain indolent or undergo high-grade change. There are no consensus guidelines on the follow-up of non-optic pathway glioma (non-OPG) tumours in NF1. One hundred patients from the National NF1 Service with generalised NF1 and a diagnosis of non-OPG glioma were followed up for a median time of 63 months after glioma detection. Forty-two patients underwent surgical intervention. Ninety-one percent (38) of those requiring surgery did so within 5 years of diagnosis of glioma. Serial neuroimaging was undertaken in 88 patients. In 66 (75%), the lesion on the scan was stable or had improved at follow-up. High-grade lesions were present in five patients and were strongly associated with tumours in the thalamus (p = 0.001). Five patients died during follow-up. The diagnosis of high-grade glioma had a HR of 99.7 (95% CI 11.1-898.9, p < 000.1) on multivariate Cox regression to evaluate predictive factors related to death. In our cohort of 100 patients with NF1, we have shown that tumours in the thalamus are more likely to be associated with radiological progression, high-grade tumours, and surgical intervention. As a result of this finding, heightened surveillance with more frequent imaging should be considered in thalamic involvement. We have also demonstrated that over 40% of patients underwent surgery, and did so within 5 years of tumour diagnosis. Serial imaging should be undertaken for at the very least, 5 years from tumour detection.

Peripheral nerve sheath tumors of the breast

Benign and malignant peripheral nerve sheath tumors can involve the breast, presenting as masses in the dermis, deep breast parenchyma or axillary soft tissue. Although the histologic features are frequently characteristic, diagnosis can be challenging on core needle biopsy, and the differential diagnosis includes a variety of other benign and malignant spindle cell lesions of the breast. Here, we review the key clinical and pathological features of breast schwannoma, neurofibroma, granular cell tumor, and malignant peripheral nerve sheath tumor.

Malignant Peripheral Nerve Sheath Tumors State of the Science: Leveraging Clinical and Biological Insights into Effective Therapies

Malignant peripheral nerve sheath tumor (MPNST) is the leading cause of mortality in patients with neurofibromatosis type 1. In 2002, an MPNST consensus statement reviewed the current knowledge and provided guidance for the diagnosis and management of MPNST. Although the improvement in clinical outcome has not changed, substantial progress has been made in understanding the natural history and biology of MPNST through imaging and genomic advances since 2002. Genetically engineered mouse models that develop MPNST spontaneously have greatly facilitated preclinical evaluation of novel drugs for translation into clinical trials led by consortia efforts. Continued work in identifying alterations that contribute to the transformation, progression, and metastasis of MPNST coupled with longitudinal follow-up, biobanking, and data sharing is needed to develop prognostic biomarkers and effective prevention and therapeutic strategies for MPNST.

[Soft tissue tumors in hereditary tumor syndromes]

Benign and malignant soft tissue tumors usually develop de novo without identifiable risk factors or predisposing conditions. However, in recent decades, soft tissue tumors have been increasingly recognized to be associated with diverse hereditary tumor syndromes as a consequence of germline mutations involving mainly tumor suppressor genes, but rarely also affecting proto-oncogenes. This is mainly the consequence of increasing application of modern genetic analysis tools, such as next-generation sequencing (NGS) and whole genome analyses. Syndrome-associated soft tissue tumors frequently show distinctive clinicopathological features and peculiarities that facilitate and potentially enhance their recognition and identification during routine surgical pathology practice. As it is not uncommon that pathologists are the first medical specialists to recognize a potential hereditary etiology of neoplastic diseases on the basis of specific pathological features, it is mandatory that pathologists be familiar with the main features that characterize those soft tissue tumors with inherited etiology, at least the most common and important of them. This review summarizes the main syndromes and their associated soft tissue tumors and discusses their characteristic pathological features that help in the recognition of hereditary syndromes.

Current status and recommendations for biomarkers and biobanking in neurofibromatosis

OBJECTIVE

Clinically validated biomarkers for neurofibromatosis 1 (NF1), neurofibromatosis 2 (NF2), and schwannomatosis (SWN) have not been identified to date. The biomarker working group's goals are to (1) define biomarker needs in NF1, NF2, and SWN; (2) summarize existing data on biomarkers in NF1, NF2, and SWN; (3) outline recommendations for sample collection and biomarker development; and (4) standardize sample collection and methodology protocols where possible to promote comparison between studies by publishing standard operating procedures (SOPs).

METHODS

The biomarker group reviewed published data on biomarkers in NF1, NF2, and SWN and on biobanking efforts outside these diseases via literature search, defined the need for biomarkers in NF, and developed recommendations in a series of consensus meetings.

RESULTS

We describe existing biomarkers in NF and report consensus recommendations for SOP and a minimal clinical dataset to accompany samples derived from patients with NF1, NF2, and SWN in decentralized biobanks.

CONCLUSIONS

These recommendations are intended to provide clinicians and researchers with a common set of guidelines to collect and store biospecimens and for establishment of biobanks for NF1, NF2, and SWN.

Optic Pathway Gliomas Secondary to Neurofibromatosis Type 1

Children with neurofibromatosis type 1 frequently manifest optic pathway gliomas-low-grade gliomas intrinsic to the visual pathway. This review describes the molecular and genetic mechanisms driving optic pathway gliomas as well as the clinical symptoms of this relatively common genetic condition. Recommendations for clinical management and descriptions of the newest imaging techniques are discussed.

Epilepsy Mechanisms in Neurocutaneous Disorders: Tuberous Sclerosis Complex, Neurofibromatosis Type 1, and Sturge-Weber Syndrome

Neurocutaneous disorders are multisystem diseases affecting skin, brain, and other organs. Epilepsy is very common in the neurocutaneous disorders, affecting up to 90% of patients with tuberous sclerosis complex (TSC) and Sturge–Weber syndrome (SWS), for example. The mechanisms underlying the increased predisposition to brain hyperexcitability differ between disorders, yet some molecular pathways overlap. For instance, the mechanistic target of rapamycin (mTOR) signaling cascade plays a central role in seizures and epileptogenesis in numerous acquired and genetic disorders, including several neurocutaneous disorders. Potential routes for target-specific treatments are emerging as the genetic and molecular pathways involved in neurocutaneous disorders become increasingly understood. This review explores the clinical features and mechanisms of epilepsy in three common neurocutaneous disorders—TSC, neurofibromatosis type 1, and SWS.

Diagnostic and Prognostic Relevance of the Cutaneous Manifestations of Neurofibromatosis Type 2

Neurofibromatosis type 2 is an autosomal dominant hereditary disease with complete penetrance. It gives rise to multiple central and peripheral nervous system tumors, ocular alterations, and various types of skin lesion. In general, neither dermatologists nor other specialists have in-depth knowledge of the clinical manifestations of neurofibromatosis type 2. In some cases, this can lead to delayed diagnosis, which can increase morbidity and mortality. We describe the less well known clinical manifestations of NF2, focusing particularly on skin lesions specific to this disease. Identification of these lesions, when present, can facilitate diagnosis.

Evaluation of quality of life in adults with neurofibromatosis 1 (NF1) using the Impact of NF1 on Quality Of Life (INF1-QOL) questionnaire

Background

Neurofibromatosis 1 (NF1) is an inherited, multi-system, tumour suppressor disorder with variable complications that cause psychological distress and social isolation. The study aim was to develop and validate a disease-specific questionnaire to measure quality of life (QOL) in NF1 that is suitable both as an assessment tool in clinical practice and in clinical trials of novel therapy.

Methods

The Impact of NF1 on Quality of Life (INF1-QOL) questionnaire was developed by a literature search for common terms, focus group (n = 6), semi-structured interviews (n = 21), initial drafts (n =50) and final 14 item questionnaire (n = 50). Bivariate correlations between items, exploratory factor analysis, correlations with severity and EuroQol were employed.

Results

INF1-QOL showed good internal reliability (Cronbach’s alpha 0.87), mean total INF1-QOL score was 8.64 (SD 6.3), median 7.00, range 0–30 (possible range 0–42); no significant correlations with age or gender. The mean total EuroQol score was 7.38 (SD 2.87), median 6.5, mean global EuroQol score was 76.34 (SD 16.56), median 80. Total INF1-QOL score correlated with total EuroQol r = 0.82, p < 0.0001. The highest impact on QOL was moderate or severe problems with anxiety and depression (32%) and negative effects of NF1 on role and outlook on life (42%). The mean inter-relater reliability for grading of clinical severity scores was 0.71 (range 0.65-0.79), and intra-class correlation was 0.92. The mean clinical severity score was 1.95 (SD 0.65) correlating r = 0.34 with total INF1-QOL score p < 0.05 and correlated 0.37 with total EuroQol score p < 0.01. The clinical severity score was mild in 17 (34%), moderate in 16 (32%) and 17 (34%) individuals had severe disease.

Conclusions

INF1-QOL is a validated, reliable disease specific questionnaire that is easy and quick to complete. Role and outlook on life and anxiety and depression have the highest impact on QOL indicating the variability, severity and unpredictability of NF1. INFI-QOL correlates moderately with clinical severity. The moderate relationship between INF1-QOL and physician rated severity emphasizes the difference between clinical and patient perception. INFI-QOL will be useful in individual patient assessment and as an outcome measure for clinical trials.

Electronic supplementary material

The online version of this article (doi:10.1186/s12955-017-0607-y) contains supplementary material, which is available to authorized users.

Coexistence of Juvenile-Like Polyp with Neurofibroma at the Gastroesophageal Junction in an Adult with Neurofibromatosis Type I

A 23-year-old Caucasian male with Neurofibromatosis Type I (NF-I) was found to have a submucosal nodule at the gastroesophageal junction (GEJ) and underwent endoscopic submucosal dissection. Histological examination revealed two different lesions within the nodule. The dominant lesion was inflammatory/hyperplastic (juvenile-like) polyp with obliterative vasculopathy while the smaller lesion was a neurofibroma. Gastric/GEJ lesions in NF-I are very rare with only seven cases reported in the literature. Three cases of juvenile-like gastric polyps (located in the antrum, greater curvature, and fundus) have been reported in adult NF-I patients. An inflammatory polyp associated with a neurofibroma has only been described once in the pediatric literature but never in an adult. Our case is unique from those previously described in the literature due to the age of the patient, the presence of 2 histologically separate lesions in one endoscopically evident lesion, and the presence of obliterative vasculopathy in the juvenile-like polyp.

Phase II trial of pegylated interferon alfa-2b in young patients with neurofibromatosis type 1 and unresectable plexiform neurofibromas

Background

There is no proven medical therapy for plexiform neurofibromas (PNs). We undertook a phase II trial of pegylated interferon (PI) to evaluate response and time to progression (TTP).

Methods

PI was administered as a subcutaneous injection to patients with neurofibromatosis type 1‒related PN, stratified by the presence of symptoms (asymptomatic: stratum 1, symptomatic: stratum 2) or documented imaging progression (stratum 3). Patients in strata 1 and 2 received PI for up to one year if stable, 2 years for those with clinical (stratum 2) or imaging response (≥20% decrease in volume). Patients on stratum 3 continued PI until progression. PI was considered active in stratum 3 if TTP doubled compared with the placebo arm of a previous randomized trial using tipifarnib.

Results

Enrolled were 82 evaluable patients (median age 10 y; range 1.6 to 21.4). Fatigue and/or worsening of behavioral issues were the most common toxicities requiring dose modification. Across all strata, imaging responses were seen in 4 patients (5%). Three of 26 symptomatic patients on stratum 2 met the criteria for clinical response without corresponding imaging changes. In stratum 3, median TTP was 29.4 months versus 11.8 for the placebo arm of the previous trial (P=.031). The slope of tumor growth on PI slowed significantly compared with the slope before starting PI (P=.044).

Conclusions

In patients with active PN, PI results in more than doubling of the TTP compared with placebo. Imaging changes in symptomatic patients were not associated with changes in clinical status.

Schwannoma of the tongue-A common tumour in a rare location: A case report

Schwannoma is a benign tumour that arises from Schwann cells of the peripheral nerve sheath, and is a common tumour of the head and neck. However, intraoral location is very uncommon (only 1% of all head and neck schwannomas). We report a rare case of lingual schwannoma in a 20-year-old male patient who presented with a small, slow-growing mass over the right lateral border of the tongue with 1 year of evolution and that became recently ulcerated. The patient underwent MRI examination and complete surgical excision. Histopathological and immunohistochemical examination confirmed the diagnosis.

Activity of Selumetinib in Neurofibromatosis Type 1-Related Plexiform Neurofibromas

BACKGROUND

Effective medical therapies are lacking for the treatment of neurofibromatosis type 1-related plexiform neurofibromas, which are characterized by elevated RAS-mitogen-activated protein kinase (MAPK) signaling.

METHODS

We conducted a phase 1 trial of selumetinib (AZD6244 or ARRY-142886), an oral selective inhibitor of MAPK kinase (MEK) 1 and 2, in children who had neurofibromatosis type 1 and inoperable plexiform neurofibromas to determine the maximum tolerated dose and to evaluate plasma pharmacokinetics. Selumetinib was administered twice daily at a dose of 20 to 30 mg per square meter of body-surface area on a continuous dosing schedule (in 28-day cycles). We also tested selumetinib using a mouse model of neurofibromatosis type 1-related neurofibroma. Response to treatment (i.e., an increase or decrease from baseline in the volume of plexiform neurofibromas) was monitored by using volumetric magnetic resonance imaging analysis to measure the change in size of the plexiform neurofibroma.

RESULTS

A total of 24 children (median age, 10.9 years; range, 3.0 to 18.5) with a median tumor volume of 1205 ml (range, 29 to 8744) received selumetinib. Patients were able to receive selumetinib on a long-term basis; the median number of cycles was 30 (range, 6 to 56). The maximum tolerated dose was 25 mg per square meter (approximately 60% of the recommended adult dose). The most common toxic effects associated with selumetinib included acneiform rash, gastrointestinal effects, and asymptomatic creatine kinase elevation. The results of pharmacokinetic evaluations of selumetinib among the children in this trial were similar to those published for adults. Treatment with selumetinib resulted in confirmed partial responses (tumor volume decreases from baseline of ≥20%) in 17 of the 24 children (71%) and decreases from baseline in neurofibroma volume in 12 of 18 mice (67%). Disease progression (tumor volume increase from baseline of ≥20%) has not been observed to date. Anecdotal evidence of decreases in tumor-related pain, disfigurement, and functional impairment was observed.

CONCLUSIONS

Our early-phase data suggested that children with neurofibromatosis type 1 and inoperable plexiform neurofibromas benefited from long-term dose-adjusted treatment with selumetinib without having excess toxic effects. (Funded by the National Institutes of Health and others; ClinicalTrials.gov number, NCT01362803 .).

Orbital/Periorbital Plexiform Neurofibromas in Children with Neurofibromatosis Type 1: Multidisciplinary Recommendations for Care

TOPIC

Children and adults with neurofibromatosis type 1 (NF1), a common autosomal dominant condition, manifest a variety of ophthalmologic conditions. Plexiform neurofibromas (PNs) involving the eyelid, orbit, periorbital, and facial structures (orbital-periorbital plexiform neurofibroma [OPPN]) can result in significant visual loss in children. Equally important, OPPNs can cause significant alteration in physical appearance secondary to proptosis, ptosis, and facial disfigurement, leading to social embarrassment and decreased self-esteem.

CLINICAL RELEVANCE

Although NF1 is a relatively common disease in which routine ophthalmologic examinations are required, no formal recommendations for clinical care of children with OPPNs exist. Although medical and surgical interventions have been reported, there are no agreed-on criteria for when OPPNs require therapy and which treatment produces the best outcome.

METHODS

Because a multidisciplinary team of specialists (oculofacial plastics, pediatric ophthalmology, neuro-ophthalmology, medical genetics, and neuro-oncology) direct management decisions, the absence of a uniform outcome measure that represents visual or aesthetic sequelae complicates the design of evidence-based studies and feasible clinical trials.

RESULTS

In September 2013, a multidisciplinary task force, composed of pediatric practitioners from tertiary care centers experienced in caring for children with OPPN, was convened to address the lack of clinical care guidelines for children with OPPN.

CONCLUSIONS

This consensus statement provides recommendations for ophthalmologic monitoring, outlines treatment indications and forthcoming biologic therapy, and discusses challenges to performing clinical trials in this complicated condition.

Schwannoma of the tongue

Schwannoma, neurilemmoma or neurinoma is a rare, benign nerve sheath neoplasm composed of Schwann cells. It is usually solitary, slow growing and asymptomatic. Approximately 1-12% of the tumours occur intraorally with the tongue being the most common location. We report a rare case of lingual schwannoma in a 20-year-old female patient involving the tip of the tongue, which was slow growing and asymptomatic. For diagnosis histopathological examination and also immunohistochemistry testing were carried out to confirm the nature of tissue fragments. The treatment was complete surgical excision.

Prevalence of neurofibromatosis type 1 in congenital pseudarthrosis of the tibia

A strong relationship between congenital pseudarthrosis of the tibia (CPT) and neurofibromatosis type 1 (NF1) has been suggested, but prevalence varies widely throughout the literature and the criteria used for diagnosis are very heterogeneous. Literature focus is mainly on treatment and no specific review on the prevalence of NF1 has been published. Based on our own observations, we hypothesized the prevalence of NF1 in patients with CPT to be higher than what is previously accepted. We conducted a comprehensive literature review on this topic and compared results with our study population. Twenty-one out of twenty-five patients in the study population matched the NIH diagnostic criteria for NF1 (84.0 %, CI95 = 69.6-98.4 %). These results are higher than the prevalence reported in the literature (55.4 %, CI95 = 50.4-60.4 %).

CONCLUSIONS

The prevalence of NF1 in patients with CPT might be higher than what is reported until now because the criteria of NF1 generally appear only after the diagnosis of CPT. We propose a repeat meticulous examination and a multidisciplinary approach with a clinical genetic counseling in all CPT patients.

WHAT IS KNOWN

• Congenital pseudarthrosis of the tibia and neurofibromatosis type 1 are closely related. • Literature focus is mainly on treatment and little epidemiologic research is available. What is New: • Prevalence of neurofibromatosis type 1 in patient with congenital pseudarthrosis of the tibia might be higher than what is reported until now. • A multidisciplinary approach with meticulous clinical examination and genetic counseling might lead to an earlier diagnosis of neurofibromatosis type 1 in patients with congenital pseudarthrosis of the tibia.

An autopsy case of superficial siderosis of the central nervous system accompanied by anterior sacral polycystic meningocele in neurofibromatosis type 1

A 74-year-old female patient, who was diagnosed with neurofibromatosis type 1 (NF1) at the age of 40, was admitted with complaints of flickering vision and gait disturbance for the last 2 years. On admission, neurological examination revealed mild bilateral hearing loss and ataxia in the limb and trunk. Laboratory tests revealed anti-hepatitis C virus (HCV) antibody positivity and elevated HCV RNA by real-time polymerase chain reaction. The cerebrospinal fluid examination revealed a slightly yellowish appearance with elevated total protein levels. Gradient echo T2*-weighted brain magnetic resonance imaging (MRI) demonstrated a rim of hypointense lesions surrounding the surface of the cerebellum, brainstem, frontal and temporal lobes, and thalamus, which was considered as hemosiderin depositions. From these MRI findings, she was diagnosed as having superficial siderosis of the central nervous system. Cerebral angiography revealed an aneurysm-like dilatation at the bifurcation of the right internal carotid-posterior communicating artery. (99m)Tc-ethyl cysteinate dimer single-photon emission computed tomography revealed hypoperfusion in the bilateral frontal and temporal lobes. Pelvic plain X-ray, pelvic computed tomography, and lumbosacral MRI revealed a sacral defect and an anterior sacral polycystic meningocele communicating with the spinal subarachnoid space. The patient's symptoms gradually worsened, and she died of septic shock because of pyelonephritis at the age of 77. An autopsy was performed; on pathological examination, we did not observe any findings associated with rupture of the aneurysm-like dilatation in the bifurcation of the right internal carotid-posterior communicating artery and cerebral amyloid angiopathy. Because duropathies-a new neurological disease concept-have been implicated as a cause of bleeding in the superficial siderosis, the anterior sacral polycystic meningocele, a type of duropathies, was presumed to be the most probable bleeding source of the superficial siderosis in this patient. Bleeding from the meningocele might result from the vulnerability of vessel walls in NF1.

Quadruple-Negative GIST Is a Sentinel for Unrecognized Neurofibromatosis Type 1 Syndrome

PURPOSE

The majority of gastrointestinal stromal tumors (GIST) are driven by KIT, PDGFRA, or, less commonly, BRAF mutations, and SDH gene inactivation is involved in a limited fraction of gastric lesions. However, about 10% of GISTs are devoid of any of such alterations and are poorly responsive to standard treatments. This study aims to shed light on the molecular drivers of quadruple-negative GISTs.

EXPERIMENTAL DESIGN

Twenty-two sporadic quadruple-negative GISTs with no prior association with Neurofibromatosis Type 1 syndrome were molecularly profiled for a panel of genes belonging to tyrosine kinase pathways or previously implicated in GISTs. For comparison purposes, 24 GISTs carrying KIT, PDGFRA, or SDH gene mutations were also analyzed. Molecular findings were correlated to clinicopathologic features.

RESULTS

Most quadruple-negative GISTs featured intestinal localization, with a female predilection. About 60% (13/22) of quadruple-negative tumors carried NF1 pathogenic mutations, often associated with biallelic inactivation. The analysis of normal tissues, available in 11 cases, indicated the constitutional nature of the NF1 mutation in 7 of 11 cases, unveiling an unrecognized Neurofibromatosis Type 1 syndromic condition. Multifocality and a multinodular pattern of growth were common findings in NF1-mutated quadruple-negative GISTs.

CONCLUSIONS

NF1 gene mutations are frequent in quadruple-negative GISTs and are often constitutional, indicating that a significant fraction of patients with apparently sporadic quadruple-negative GISTs are affected by unrecognized Neurofibromatosis Type 1 syndrome. Hence, a diagnosis of quadruple-negative GIST, especially if multifocal or with a multinodular growth pattern and a nongastric location, should alert the clinician to a possible Neurofibromatosis Type 1 syndromic condition. Clin Cancer Res; 23(1); 273-82. ©2016 AACR.

Families dealing with the uncertainty of genetic disorders: the case of Neurofibromatosis Type 1

Some scholars contend that genetic medicine is transforming the experience of illness and the social category of the family - bringing future risks into the present, and potentially strengthening familial biological bonds in light of these shared genetic risks. However, research has shown that genetic information is interpreted and acted upon through a rich repertoire of adaptable social, cultural and familial factors which pre-exist and interact with biomedical knowledge. This paper reports research into families living with Neurofibromatosis Type 1 (NF1), a highly uncertain condition the manifestation of which can vary considerably also within the same family and, for this reason, has been defined as a 'condition without parameters'. These characteristics make NF1 a particularly informative condition for the examination of family dynamics around genetic information. The study and the methodology are based on the exploration of family networks and allow us to investigate the interrelation of individual and familial constructions of the uncertainty of NF1. This also allows both theoretical and policy claims to be made about the danger of reductionist thinking about the transformative potential of genetic technologies.

Sensitization of Ion Channels Contributes to Central and Peripheral Dysfunction in Neurofibromatosis Type 1

Neurofibromatosis type 1 (Nf1) is a progressive, autosomal disorder with a large degree of variability and severity of manifestations including neurological, cutaneous, ocular/orbital, orthopedic, and vascular abnormalities. Nearly half of Nf1 patients presents with cognitive impairment, specifically spatial learning deficits. These clinical manifestations suggest a global impairment of both central and peripheral nervous system functions in neurofibromatosis. Nf1 encodes for neurofibromin, a Ras GTPase-activating protein (Ras GAP) that has been implicated in the regulation of long-term potentiation (LTP), Ras/ERK (extracellular signal-regulated kinase) signaling, and learning in mice. Over the last decades, mice with a targeted mutation in the Nf1 gene, Nf1 ^-/- chimeric mice, Nf1 exon-specific knockout mice, and mice with tissue-specific inactivation of Nf1 have been generated to model the human Nf1 disease. These studies have implicated neurofibromin in regulation of the release of the inhibitory neurotransmitter γ-amino butyric acid (GABA) in the hippocampus and frontal lobe, which can regulate memory. Mutations in neurofibromin thus lead to perturbed ERK signaling, which alters GABA release, LTP, and subsequently leads to learning deficits. In addition to these cognitive deficits, Nf1 patients also have defects in fine and gross motor coordination as well as decreased muscle strength. Although the mechanisms underlying these motor deficits are unknown, deficits in GABAergic neurotransmission in both the motor cortex and cerebellum have been suggested. In this review, we present evidence to support the hypothesis that alterations of ion channel activity in Nf1 underscore the dysregulated neuronal communication in non-neuronal and neuronal cells that likely contributes to the clinical cornucopia of Nf1.