Diagnosis Of Neurofibromatosis Type Research Articles

A Challenging New Diagnosis of Neurofibromatosis Type-1 with Uncommon Vascular Manifestations in an Elderly Female (P6-9.013)

A Challenging New Diagnosis of Neurofibromatosis Type-1 with Uncommon Vascular Manifestations in an Elderly Female (P6-9.013)

Surgical treatment of a massive soft tissue neurofibroma in neurofibromatosis type 1

Introduction. Neurofibromas developing in neurofibromatosis type 1 rarely grow to a large size. However, in cases of massive lesions, selection of optimal treatment tactics can be complicated. Clinicians usually resort to surgical treatment which currently serves as an effective instrument for improving patients’ quality of life and for achieving good cosmetic results.Aim. To describe a successful experience of surgical treatment in a patient with giant neurofibroma type 1 affecting a massive pool of soft tissues.Clinical case. Patient, 22 years, sought medical help at the N.N. Blokhin National Medical Research Center of Oncology with diagnosis of neurofibromatosis type 1 with massive lesions in the tissues of the lower third of the back, gluteal region, thighs. The disease has existed since birth, family medical history is fraught: father died of malignant manifestation of a neurogenic tumor. The younger sister is also diagnosed with neurofibromatosis affecting the brain and manifesting through cafe au lait spots on the body. Due to massive tumors significantly decreasing the patient’s quality of life, cytoreductive surgical treatment was prescribed aimed at maximally radical resection of all available tumors to alleviate the patient’s condition.Conclusion. The presented clinical case demonstrates successful experience of surgical treatment of a patient with giant neurofibroma affecting a massive pool of soft tissues.

116 The Role of Spinal Surgery Among NF2 Patients With Spinal Tumors: Surgery-associated Characteristics and Response to Bevacizumab

INTRODUCTION: Neurofibromatosis type 2 (NF2) patients develop spinal neoplasms. Determining indications for spine surgery remains challenging, as localization of spine related symptoms can be confounded by intracranial or peripheral neuropathology. Additionally, patient selection must be balanced with pre-existing comorbidities NF2 incurs with the goal to maintain or improve quality of life. METHODS: Seventy-nine patients were enrolled retrospectively based upon NF2 diagnosis and radiographic presence of spine tumors from three tertiary academic centers. Demographic data, clinical findings, treatment course, and spine tumor pathology were collected for all patients. RESULTS: Forty-eight percent of patients received spine surgery (38/79, 48.1%). Patients undergoing spine surgery had lower age of symptom onset (15.4 vs. 25.6, p = 0.015), increased cervical (4.2 vs 2.4, p = 0.005) and overall spine tumor burden (10.3 vs 6.2, p < 0.001) and presence of neck (9 vs 1, p = 0.006) and radicular pain (8 vs 1, p = 0.012). Over a quarter of our patients received BEV (25/79, 31.6%), with majority experiencing symptom onset before age 20 (17/19, 89.5%). Schwannoma was the most common BEV-treated pathology. Only one patient experienced worsening of tumor burden at one year while on BEV, and five patients required spine surgery after receiving BEV. CONCLUSIONS: NF2 patients who require spine surgery typically present at younger ages with large cervical spine tumor burden and associated symptomology. It is crucial that surgery-associated demographics and symptomology are identified. BEV was utilized in patients with aggressive, early-onset spine disease. Further, BEV halted spine disease progression in all patients except one, with minimal additional spine surgery required. Its ability to slow aggressive, NF2-associated spine tumors should be considered for clinical trial.

Patient characteristics, treatment patterns, healthcare resource utilization, and costs among patients diagnosed with neurofibromatosis type 1 with and without plexiform neurofibromas in Japan

Objectives: The objectives of this study were to retrospectively investigate the patient characteristics, treatment patterns, healthcare resource utilization (HCRU), and healthcare costs related to management of neurofibromatosis type 1 (NF1) in Japan. Methods: Cohorts of NF1 patients with or without plexiform neurofibromas (PN) were identified from the Medical Data Vision database in 2008-2019. Baseline characteristics, NF1 medications, HCRU, and associated costs were assessed using descriptive statistics. All-cause HCRU and costs following the first confirmed NF1 diagnosis date were analyzed per patient per year (PPPY) in Japanese Yen (JPY) and United States Dollar (USD). Results: A total of 4,394 NF1 patients without PN and 370 NF1 patients with PN were identified. The mean age was 35.0 and 36.9 years, respectively. The proportion of patients with PN treated with medications was higher than that in patients without PN (except for antirheumatic/immunologic agents). Analgesics/non-steroidal anti-inflammatory drugs were the most frequently prescribed NF1 medications (44.3% and 56.0% in patients without and with PN, respectively), followed by inpatient prescriptions of opioids/opioid-like agents (17.8% and 27.6%, respectively). Inpatient admissions accounted for the highest costs in both cohorts with the average cost PPPY being JPY 2,133,277 (USD 19,861) for patients without PN and JPY 1,052,868 (USD 9,802) for patients with PN. Conclusions: NF1 is treated primarily with supportive care with analgesics/non-steroidal anti-inflammatory drugs being the most frequently prescribed NF1 medications in Japan. Findings underscored the unmet need and substantial economic burden among patients with NF1 and highlighted the need for new treatment options for patients with this disease.

Deciphering the Immune Microenvironment of NF1-associated Peripheral Nerve Sheath Tumors: Identifying Early Biomarkers of Disease Progression and Malignant Transformation

Background/Objective:Neurofibromatosis type 1 (NF1) is a multisystem disorder that affects ~1/3000 newborns. Plexiform neurofibromas (PN) are present in about half of cases and can transform (lifetime risk of 8-13%) into malignant peripheral nerve sheath tumor (MPNST), a highly aggressive and metastatic sarcoma with poor survival. Unfortunately, there are currently no reliable biomarkers to identify PN at risk of undergoing malignant transformation. Our research has revealed that a subset of benign-appearing and atypical PN exhibit deregulated immune surveillance and T-cell infiltration that precede malignant transformation. In this study, we are analyzing tumor microenvironment and immune landscape in NF1-related tissue specimens to identify biomarkers of disease progression. To power these studies, this project focused on constructing a dataset of NF1-related samples to be analyzed.
 Methods:701 patients were identified via Cerner billing codes and pathology archives. De-identified clinical data, including presenting symptoms, relevant clinical history, pathology diagnoses, disease features, prior chemotherapeutics/radiation, prior gene profiling, and imaging features were collected.
 Results: We selected 86 patients with a total of 175 samples. 81% of patients had a clinical diagnosis of NF1, and 6% had a history of MPNST. Out of the 175 samples, 54 were in the head and neck, 42 in the thorax, 28 in the lower extremity, 27 in the upper extremity, 26 in the pelvis/abdomen, and 15 in the paraspinal region. The leading causes of procedures were pain (41%), growth (40%), and concern for malignancy (27%). The most common tissue diagnoses were neurofibroma (51.4%), PN (20%), and undefined-grade MPNST (11%). Out of the 46 MPNSTs, 30 were primary tumors, 4 metastases, and 12 local recurrences.
 Conclusion and Potential Impact:The results of this study will provide valuable insights to inform preclinical models of NF1-tumorigenesis to validate these findings and identify novel treatment approaches for individuals affected by these rare but devastating tumors.

Dental Developmental Stages and Decayed, Missing, and Restored Teeth in Neurofibromatosis Type 1-affected Children and Adolescents.

Neurofibromatosis type 1 (NF1) is an autosomal dominant inherited tumor predisposition disease with a highly variable phenotype. The influence of the characteristic NF1 tumors (neurofibromas) on dentition has not yet been examined in detail. The aim of the study was to assess the dentition of NF1 children and adolescents, considering the symmetry of tooth development. The panoramic radiographs of 59 patients with a confirmed NF1 diagnosis were compared with 59 age-and-sex-matched controls. The stages of tooth development on the sides of the jaw, added to a score, were assessed. In addition, the number of filled or decayed teeth, and the number of retained or missing teeth were assessed. The tooth development of both study groups is symmetrical for almost all parameters and in the same developmental stage according to the sum score of the tooth development stages. Discrete developmental delays of teeth, in particular in the oral area of facial plexiform neurofibroma (PNF) are noticeable. NF1 patients' teeth showed less decay and more restorations than that of the control group. The facial PNF (FPNF) does not impair emergence of deciduous teeth. Development of dentition of NF1 patients does not differ from the general population. However, FPNF with oral tumor components often prevent mesial movement of permanent molars and premolars, so these teeth do not develop contact (spacing), hardly emerge or may stay retained in bone. Oral PNF may have a low-retarding effect on some tooth root development (e.g., wisdom teeth). This effect is negligible when comparing the affected and unaffected sides of the jaw and is probably non-specific. Key words:Neurofibromatosis type 1, plexiform neurofibroma, dentition, mixed dentition, symmetry, oral health, tooth development.

P11.43.B HIGH-RESOLUTION NERVE ULTRASOUND IN NEUROFIBROMATOSIS TYPE 1

Abstract BACKGROUND Patients with neurofibromatosis type 1 (NF1) can develop plexiform neurofibromas (PN). PN are peripheral nerve sheath tumors that can cause pain, neurological deficit and can transform into malignant peripheral nerve sheath tumors (MPNST). High-resolution ultrasound (HRUS) is suggested as a quick and cost-effective technique, as compared to whole-body MRI, for screening NF1 patients for PN. Our aim is to describe the variety of HRUS nerve abnormalities in NF1 patients and to study the link between nerve morphology and nerve function. MATERIAL AND METHODS We selected patients with a clinical diagnosis of NF1, with or without symptoms related to the peripheral nervous system (PNS) such as pain, sensory disturbances or loss of strength. Patients were invited for a study visit including neurological examination, nerve conduction studies (NCS) and HRUS. One-sided NCS were performed of the median and ulnar nerve (motor and sensory), peroneal and tibial nerve (motor) and sural nerve according to standard protocol. We visualised the brachial plexus, median-, radial-, ulnar-, peroneal-, tibial-, and sural nerves on both sides using HRUS. The cross-sectional area (CSA) of the nerve was measured at predefined anatomical sites, and additional sites in case of focal nerve enlargement. RESULTS We enrolled 60 NF1 patients, of which 57% had PNS-related symptoms. One third of our patients had neurological deficits during physical examination. We found nerve enlargement with HRUS in 48 out of 60 patients (80%), this was not significantly different between patients with PNS symptoms or without PNS symptoms (82% vs 77% respectively, p=0.602). In 82% of the patients with PNS symptoms, their symptoms were likely to be related to one or more nerve enlargements. Nine of these patients had clinical and neurophysiological signs of carpal tunnel syndrome. Different patterns of nerve enlargement were identified. 46% had isolated nerve enlargements, 25% had diffusely enlarged nerves and 29% had a mixture of diffusely enlarged nerves with isolated nerve enlargements. The majority of the patients with nerve enlargement on HRUS had no abnormalities on NCS (65%). CONCLUSION The majority of NF1 patients have nerve enlargements as seen by HRUS, however we have shown that nerve enlargements can often be asymptomatic and do not always lead to impaired nerve function. To determine whether patients have PN cannot be based solely on clinical evaluation of symptoms. HRUS might have an application as a screening tool for NF1 patients in clinical practice. However, further research is needed to describe growth of nerve enlargements, the impact of intra- and interobserver variability on CSA measurements and to improve our knowledge on the link between nerve morphology and nerve function in NF1.

Characterizing T-cell dysfunction and exclusion signatures in malignant peripheral nerve sheath tumors reveals susceptibilities to immunotherapy.

Malignant peripheral nerve sheath tumors (MPNSTs) are malignant tumors that arise from peripheral nerves and are the leading cause of mortality in Neurofibromatosis Type 1 (NF1). In this study, we characterized whether transcriptomic signatures of T-cell dysfunction (TCD) and exclusion (TCE) that inversely correlate with response to immune checkpoint blockade (ICB) immunotherapy exist in MPNSTs. MPNST transcriptomes were pooled from Gene Expression Omnibus (GEO). For each sample, a tumor immune dysfunction and exclusion (TIDE) score, TCD and TCE subscores, and cytotoxic T-cell(CTL) level were calculated. In the TIDE predictive algorithm, tumors are predicted to have an ICB response if they are either immunologically hot (CTL-high) without TCD or immunologically cold (CTL-low) without TCE. TIDE scores greater than zero correspond with ICB nonresponse. 73 MPNST samples met inclusion criteria, including 50 NF1-associated MPNSTs (68.5%). The average TIDE score was + 0.41 (SD = 1.16) with 22 (30.1%) predicted ICB responders. 11 samples were CTL-high (15.1%) with an average TCD score of + 0.99 (SD = 0.63). Among 62 CTL-low tumors, 21 were predicted to have ICB response with an average TCE score of + 0.31(SD = 1.20). Age(p = 0.18), sex(p = 0.41), NF1 diagnosis (p = 0.17), and PRC2 loss(p = 0.29) were not associated with ICB responder status. Transcriptomic analysis of TCD and TCE signatures in MPNST samples reveals that a select subset of patients with MPNSTs may benefit from ICB immunotherapy.

Schwannomatosis: a Realm Reborn: year one.

In 2022, an international consensus recommendation revised the nomenclature for neurofibromatosis type 2 (NF2) and Schwannomatosis (SWN), now grouped under the umbrella term Schwannomatosis, and defined new diagnostic criteria. This review describes the molecular criteria for diagnosis of schwannomatosis and the subsequent diagnosis strategy, while setting out the most recent advances in our understanding of the natural history, pathology, molecular biology and treatment of schwannomatosis-associated tumors, including schwannomas, meningiomas and ependymomas. Somatic mutation screening should become a new standard for the diagnosis of NF2-, LTZTR1-, SMARCB1- and 22q-schwannomatosis to discriminate those conditions. Constitutional events in NF2-Schwannomatosis have a major influence on disease severity and justifiably motivate ongoing efforts on gene replacement therapy research. On the other hand, underlying mechanisms of disease severity and associated pain remain largely unknown in non-NF2-SWN and independent of germline mutation. Research efforts therefore focus on pain relief in ongoing trials and the discovery of new molecular mechanisms underlying schwannoma tumorigenesis/pain/neuropathies.

Clinical signs and genetic evaluation of patients with neurofibromatosis type 1 with and without optic pathway gliomas in a center in Turkey.

Optic pathway gliomas (OPGs) occur in 15% of patients with neurofibromatosis type 1 (NF1). Their location renders biopsy or surgical resection difficult because of the risk of vision loss. Therefore, only a few NF1-OPGs have been used for tissue diagnosis, and only a few analyses have been published on the molecular changes that drive tumorigenesis. Due to this reason, we evaluated 305 NF1 patients, 34 with OPG and 271 without OPG for germ line mutations. All subjects underwent clinical examination and DNA analysis of NF1, confirming the diagnosis of NF1. Clinically, the group with OPG had a significantly higher incidence of bone dysplasia (P < 0.001) and more café-au-lait spots (P = 0.001) compared to those in the group without OPG. The frequency of Lisch nodules was on the borderline of statistical significance (P = 0.058), whereas the frequency of neurofibromas did not differ significantly (cutaneous, P = 0.64; plexiform, P = 0.44). Individuals with OPG mostly had mutations in the first one-third of the NF1 gene compared with that in patients who did not have OPG. Some identical mutations were detected in unrelated families with NF1-OPG. The observation of certain phenotypic features and the correlation between genotype and phenotype might help to determine the risk of developing OPG with NF1.

Neurofibromatosis type 1, from gene mutation to clinical presentation

Neurofibromatosis type 1 (NF1) is an autosomal dominant disease with a prevalence of about1/3000. The clinical diagnosis of NF1 is based on the presence of two or more of the followingcriteria: six or more café au lait spots, &gt;2 neurofibromas of any type, freckling in the axillary oringuinal region, optic glioma, a distinctive osseous lesion such as sphenoid dysplasia or thinning oflong bone cortex with or without pseudoarthrosis, and a first degree relative with NF1.We report A 7-year-old male with multiple café au lait spots diagnosed with Neurofibromatosisin Kigali-Rwanda by using next-generation sequencing and copy number variation analysis, thepatient presented with painless nodular skin lesions that first developed 4 years earlier. Skinnodules initially appeared on the anterior chest wall and progressed to the posterior chest wallextending to the axilla region. His medical history and that of his family were unremarkable. To ourknowledge, this is the first case to be diagnosed using this technology; The disease has numerouscomplications. The mutation rate for NF1-gene is high; 50% of all cases of NF1 are from newmutations. The gene protein product - neurofibromin plays an important role in tumor genesis asa tumor-suppressor gene.Combining both clinical findings and molecular genetic evaluation to identify disease-causingmutations is paramount in confirming the diagnosis. Patient care is best done in a multidisciplinarysetting approach for proper patient satisfaction and better prediction of future prognosis.

Prospects for diagnostics and treatment of neurofibromatosis type 1 in Russia

Purpose of the study. Analysis of available data on modern methods of diagnosis and treatment of neurofibromatosis type 1 (NF1) and their application in the Russian Federation. Material and Methods. The search for relevant sources was carried out in the Scopus, Web of Science, PubMed, Elibrary systems, including publications from February 1992 to December 2022. Of the 1873 scientific articles found, 48 were used to write a systematic review. Results. Neurofibromatosis type 1 (NF1) is caused by germline heterozygous mutations in the NF1 gene, which encodes the neurofibromin protein, which suppresses mitogen-activated signaling pathways necessary for cell proliferation. Clinical manifestations of NF1 are similar to Peutz–Jeghers, Laugier–Hunziker, Rusalkab–Muret–Smith, Bannayan–Zonnana, LEOPARD syndromes, neurofibromatosis type 2 and lipomatosis; therefore, to confirm the diagnosis, the most important criterion is the detection of a gene mutation by sequencing, since there are no mutagenesis hotspots in the NF1 gene. To detect 17q11.2 locus microdeletions, MLPA method is used. In Russia, such methods of molecular genetic identification of NF1 were carried out in Moscow and in the Republic of Bashkortostan. Surgical interventions using a neodymium laser and therapy with mitogen-activated protein kinase inhibitors are the most effective for the treatment of tumor syndrome. Scientific results of the use of a surgical laser in the treatment of plexiform neurofibromas and extramedullary tumors of the spinal cord have been published in Russia. Treatment of NF1 with selumetinib in Russia was announced by the interregional public organization for assistance to patients with neurofibromatosis “22/17”, which provides the drug to children with inoperable neurofibromas free of charge. Conclusion. In modern medicine, it is necessary to widely use methods for identifying mutations in the NF1 gene by creating universal panels of targeted sequencing. This will allow not only the differential diagnosis of NF1, but also the identification of the cause of chemoresistance of sporadic malignant neoplasms for the introduction of mitogen-activated protein kinase inhibitors in their treatment. Combination of this method with surgical excision of neurofibromas using a neodymium laser is optimal.

FUNCTIONAL ANALYSIS OF AN NF1 SPLICING MUTATION THAT CAUSED EXON SKIPPING AND LED TO A TRUNCATED PROTEIN IN NEUROFIBROMATOSIS TYPE 1

Objective: Neurofibromatosis type 1 (NF-1) is caused by mutations in the NF1 gene that encodes neurofibromin, a negative regulator of RAS proto-oncogene. Approximately one-third of the reported pathogenic mutations in NF1 are splicing mutations, suggesting that splicing mutations are not rare. The objective of this study was to identify the pathogenicity of splicing mutation in a Chinese family with NF-1 and determine the effects of the pre-mRNA splicing mutation by in vitro functional analysis. Design and method: Next-generation sequencing was used to screen candidate mutations and Sanger sequencing was performed for validation. We performed a minigene splicing assay to determine the effect of the splicing mutation on NF1 expression and three-dimensional structure models of wild-type and mutant-type neurofibromin were generated using SWISS-MODEL and PROCHECK method, respectively. Results: Next-generation sequencing analysis identified a pathogenic splicing mutation c.479 + 1G&gt;C in NF1 in the proband who had typical pigmental lesions and severe renal artery hypertension. We speculated that the causative mutation originated from the proband's mother who died of glioma. The minigene splicing assay showed that the c.479 + 1G&gt;C mutation caused the skipping of exon 4, leading to a Glutamine to Valine substitution at position 97 in neurofibromin and an open reading frame shift terminating at codon 108. Three-dimensional modelling of neurofibromin showed that several major domains were missing in the truncated protein, which would have affected its function. Conclusions: The splicing mutation c.479 + 1G&gt;C identified in a Chinese pedigree with NF-1 caused the skipping of exon 4 and resulted in a truncated protein. Our findings would be of great significance for the molecular diagnosis and management of NF-1 and showed that the minigene splicing assay is a powerful tool for analyzing mRNA expression outcomes caused by donor splicing site variation.

Is neurofibromatosis type 1 diagnosed in every patient who presents with café au lait macules? A single-center experience

Objective: Neurofibromatosis type 1 (NF1) is the most common hereditary neurocutaneous syndrome. The most crucial morbidity of&#x0D; NF1 is tumors that may develop. Cases with café-au-lait macules (CALMs) which is the first clinical finding of NF1, due to the anxiety&#x0D; of its associated morbidity, are referred to the pediatric oncology clinic. In this study, we aimed to examine the characteristics of the&#x0D; patients who applied to our outpatient clinic with CALMs.&#x0D; Patients and Methods: The data of 157 pediatric patients who applied to our institution with the diagnosis of CALMs between June&#x0D; 2010 and November 2020 were analyzed retrospectively.&#x0D; Results: There were 157 pediatric cases referred to us for CALMs. According to the National Institutes of Health (NIH) diagnostic&#x0D; criteria, 109 (69.4%) cases were diagnosed with NF1. The diagnosis of 22 cases with NF1 were supported by genetic examination.&#x0D; Optic glioma was detected in 39 (24.8%) cases. In 15 (38.4%) of cases with optic glioma, visual functions were also affected. Second&#x0D; diagnostic criterion did not develop during the follow-up period, except for macules, in 48 cases (30.5%).&#x0D; Conclusion: In cases with multiple CALMs, the probability of NF1 diagnosis is high, and close and regular follow-up is of great&#x0D; importance in catching the development of the second clinical criterion and minimizing its morbidity.

Selumetinib (Koselugo)

&#x0D; CADTH recommends that Koselugo be reimbursed by public drug plans for the treatment of pediatric patients aged 2 years and above, with neurofibromatosis type 1 (NF1) who have symptomatic, inoperable plexiform neurofibromas (PNs), if certain conditions are met.&#x0D; Koselugo should only be covered to treat patients who are aged between 2 and 18 years with a diagnosis of NF1 with PNs that are causing symptoms and cannot be completely removed by surgery.&#x0D; Koselugo should only be reimbursed if prescribed by specialists with experience in managing NF1 and PNs, and the cost of Koselugo is reduced. To continue treatment with Koselugo longer than 18 months, the treating physician must provide proof that the patient is responding to treatment, including but not limited to reductions in symptoms of pain, improved motor function, and/or stabilization of disease, or proof of shrinking of tumours.&#x0D;

175P Breast cancer in neurofibromatosis type 1: A retrospective review in the Portuguese population

Neurofibromatosis type 1 (NF1) is a condition predisposing to the development of benign and malignant tumors. Regarding breast cancer, an increased risk has not been widely recognized or accepted. Given the oncogenic potential, long-term surveillance is important. We selected from a pool of 468 pts with NF1 from a site of reference in Portugal women >18 years and observed how they were screened for breast cancers (BC). Also, we evaluated the percentage of those who developed BC in our population, discussing the clinical evidence of increased BC risk in women with NF1 and the potential need for a high-risk screening protocol. We identified 179 women with NF1, 19 cases being excluded due to missing data. 114pts (71%) with confirmation of diagnosis NF1, the majority with familial history and 47% with spontaneous mutation. 17 with mutations identified, c.17657C>G, p (His553Asp) being the most prevalent (2 pts). 67% were under the age 50 years (y) at the time of data analysis. The median age was 43y (15-82) and at diagnosis of NF1 was 26 (1-62). For women <30y, only 2 pts started breast screening, due to breast alterations on breast palpation. No tumor was found. Above that, 92 pts were screened, mammography and breast ultrasound (71 pts) were the most required exam, followed by breast magnetic resonance imaging (MRI) (18pts) and with both (3pts). The periodicity was not sustained, with the time between exams being variable (annual to 3/3y). Medium BI-RADS 2, but 13 pts with BI-RADS 3. 23 patients without any screening tests beside all body MRI. There were 17 cases of BC in the follow-up period, however, twelve occurred in women in their 40s (median age 43y at diagnosis); 73% were < 50. The majority of the population presented with a grade 2 tumour, with hormone-receptor-positive BC (10), followed by HER2 amplification (4) and TNBC (1). Also, 2pts had two BC during the follow-up. However, we observe an early stage BC (I-II), with only 2 patients progressing to first-line treatment, being the only deaths observed in our population. Proposals for NF1 care and its specific manifestations have been developed but lack integration within routine care. This study reinforces that increased attention to the breast cancer risk in young women with NF1 is needed.

Functional Assays Combined with Pre-mRNA-Splicing Analysis Improve Variant Classification and Diagnostics for Individuals with Neurofibromatosis Type 1 and Legius Syndrome

Neurofibromatosis type 1 (NF1) and Legius syndrome (LS) are caused by inactivating variants in NF1 and SPRED1. NF1 encodes neurofibromin (NF), a GTPase-activating protein (GAP) for RAS that interacts with the SPRED1 product, Sprouty-related protein with an EVH (Ena/Vasp homology) domain 1 (SPRED1). Obtaining a clinical and molecular diagnosis of NF1 or LS can be challenging due to the phenotypic diversity, the size and complexity of the NF1 and SPRED1 loci, and uncertainty over the effects of some NF1 and SPRED1 variants on pre-mRNA splicing and/or protein expression and function. To improve NF1 and SPRED1 variant classification and establish pathogenicity for NF1 and SPRED1 variants identified in individuals with NF1 or LS, we analyzed patient RNA by RT-PCR and performed in vitro exon trap experiments and estimated NF and SPRED1 protein expression, RAS GAP activity, and interaction. We obtained evidence to support pathogenicity according to American College of Medical Genetics guidelines for 73/114 variants tested, demonstrating the utility of functional approaches for NF1 and SPRED1 variant classification and NF and LS diagnostics.

Neuropsychiatric Manifestations, Reduced Self-Esteem and Poor Quality of Life in Children and Adolescents with Neurofibromatosis Type 1 (NF1): The Impact of Symptom Visibility and Bullying Behavior.

Neurofibromatosis type 1 (NF1) is an autosomal dominant condition, associated with neurocutaneous manifestations and neuropsychiatric manifestations. The present study explored the prevalence of bullying/cyberbullying behaviors and victimization behaviors in a cohort of children and adolescents with NF1. Possible gender differences and predictors of psychological symptoms, quality of life (QoL), and self-esteem were also examined. Thirty-eight school-aged participants with NF1 completed a psychological evaluation designed to assess anxiety and depression symptomatology, QoL, self-esteem, and the prevalence and extent of bullying/cyberbullying and victimization behaviors. We found that our participants frequently reported victimization behaviors rather than bullying/cyberbullying ones. Moreover, participants complained of depressive and anxiety symptomatology together with reduced self-esteem, and low psychosocial quality of life, with females reporting more severe performances than males. Furthermore, we found that reduced self-esteem was associated with more visibility of the NF1 symptoms, and victimization behaviors were found to mediate the relationship between anxiety and psychosocial QoL. Our findings indicated the presence of a maladaptive loop in children and adolescents with NF1 patients characterized by psychological symptoms, unfavorable self-perception, low self-esteem, and psychosocial difficulties that might be worsened by experiencing victimization behaviors. These results suggest the need to use a multidisciplinary approach in the diagnosis and treatment of NF1.

Relative size of fungiform papillae in patients with neurofibromatosis Type 1

ObjectiveTo explore possible manifestations of neurofibromatosis on the tongue, especially, enlarged papillae fungiformes. According to the literature, enlarged fungiform papillae of the tongue are a very common oral finding in patients with Neurofibromatosis Type 1 (NF1). Materials and MethodsFirstly, photos of 18 NF1 patients’ tongues, taken at different times were compared to rule of possible fluctuating papillae size. Secondly, 60 photos of 60 patients with NF1 were age/sex matched, blinded and compared to 60 photos of 60 healthy patients. Three independent medical doctors rated the photos in regard of the fungiform papillae as smaller/same/larger at two different times. The inter- and intraindividual results were compared.Thirdly, fungiform papillae of 11 NF1 patients were quantitatively measured using the Denver protocol. ResultsThe fungiform papillae showed a stable size. The comparison of the healthy individuals to the NF1 patients suggests that the larger papillae are significantly more frequent in NF1 patients than in age- and gender-matched non-NF1 individuals. The agreement between two ratings of each of the 3 raters at different time points was two moderate and one substantial, the agreement among raters was only fair, since the Fleiss’ Kappa value of all 6 ratings was 0.38. ConclusionAlthough this study confirms that the evaluation of the size of the fungiform papillae by visual inspection only is very subjective, the fungiform papillae in NF1 patients do seem to be enlarged at a statistically significant level. Nonetheless the statistical difference is not distinctive enough to establish this as a diagnostic tool in diagnosing NF1. Clinical RelevanceFacilitating the diagnosis of NF1 is an important factor in finding the correct treatment for these patients. A clinical inspection of the tongue is a simple and non-invasive procedure. This paper addresses the question if an inspection of the tongue, especially the fungiform papillae is a reliable indicator for the diagnosis of NF1.

Using a semi-automated approach to quantify Unidentified Bright Objects in Neurofibromatosis type 1 and linkages to cognitive and academic outcomes

Neurofibromatosis type 1 (NF1) is an autosomal dominant neurocutaneous syndrome that affects multiple organ systems resulting in widespread symptoms, including cognitive deficits. In addition to the criteria required for an NF1 diagnosis, approximately 70% of children with NF1 present with Unidentified Bright Objects (UBOs) or Focal Areas of Signal Intensity, which are hyperintense bright spots seen on T2-weighted magnetic resonance images and seen more prominently on FLAIR magnetic resonance images (Sabol et al., 2011). Current findings relating the presence/absence, quantities, sizes, and locations of these bright spots to cognitive abilities are mixed. To contribute to and hopefully disentangle some of these mixed findings, we explored potential relationships between metrics related to UBOs and cognitive abilities in a sample of 28 children and adolescents with NF1 (M=12.52 years; SD=3.18 years; 16 male). We used the Lesion Segmentation Tool (LST) to automatically detect and segment the UBOs. The LST was able to qualitatively and quantitatively reliably detect UBOs in images of children with NF1. Using these automatically detected and segmented lesions, we found that while controlling for age, biological sex, perceptual IQ, study, and scanner, “total UBO volume”, defined as the sum of all the voxels representing all of the UBOs for each participant, helped explain differences in word reading, phonological awareness, and visuospatial skills. These findings contribute to the emerging NF1 literature and help parse the specific deficits that children with NF1 have, to then help improve the efficacy of reading interventions for children with NF1.