Stimulator of interferon gene facilitates recruitment of effector CD8 T cells that drive neurofibromatosis type 1 nerve tumor initiation and maintenance.

Plexiform neurofibromas (PNFs) are benign nerve tumors driven by loss of the NF1 tumor suppressor in Schwann cells. PNFs are rich in immune cells, but whether immune cells are necessary for tumorigenesis is unknown. We show that inhibition of stimulator of interferon gene (STING) reduces plasma CXCL10, tumor T cell and dendritic cell (DC) recruitment, and tumor formation. Further, mice lacking XCR-1+ DCs showed reduced tumor-infiltrating T cells and PNF tumors. Antigen-presenting cells from tumor-bearing mice promoted CD8+ T cell proliferation in vitro, and PNF T cells expressed high levels of CCL5, implicating T cell activation. Notably, tumors and nerve-associated macrophages were absent in Rag1-/-; Nf1f/f; DhhCre mice and adoptive transfer of CD8+ T cells from tumor-bearing mice restored PNF initiation. In this setting, PNF shrunk upon subsequent T cell removal. Thus, STING pathway activation contributes to CD8+ T cell-dependent inflammatory responses required for PNF initiation and maintenance.

[Emergency management and perioperative strategies for intra-tumoral hemorrhage in neurofibromatosis type 1-related giant plexiform neurofibroma].

Objective: To review the emergency management and perioperative strategies for ruptured neurofibromatosis type 1 (NF1)-related giant plexiform neurofibroma (PNF), providing a systematic treatment protocol to improve the therapeutic outcomes and quality of life for patients with giant PNF. Methods: The literature on the management of giant PNF rupture and hemorrhage was reviewed, and the diagnosis, treatment, and perioperative management were summarized based on clinical experiences. Results: By implementing an integrated diagnostic and treatment strategy that includes early diagnosis, imaging evaluation, emergency ultra-selective arterial embolization combined with surgical excision, acute hemorrhage can be effectively controlled while also reducing the risk of major intraoperative bleeding and minimizing postoperative complications. As a result, this approach significantly improves treatment success rates and patient quality of life. Conclusion: For ruptured NF1-related giant PNF, employing emergency ultra-selective arterial embolization combined with surgical excision, under the collaboration of a multidisciplinary team, can effectively improve treatment success rates, rapidly control bleeding, reduce tumor size, and lower mortality. Future research should focus on assessing the long-term quality of life of patients treated for ruptured and hemorrhaging giant PNF and on further optimizing treatment protocols.

[Progress in neurosurgical treatment of neurofibromatosis type 1].

Objective: To summarize the latest developments in neurosurgical treatments for neurofibromatosis type 1 (NF1) and explore therapeutic strategies to provide comprehensive treatment guidelines for clinicians. Methods: The recent domestic and international literature and clinical cases in the field of NF1 were reviewed. The main types of neurological complications associated with NF1 and their treatments were thorough summarized and the future research directions in neurosurgery was analyzed. Results: NF1 frequently results in complex and diverse lesions in the central and peripheral nervous systems, particularly low-grade gliomas in the brain and spinal canal and paraspinal neurofibromas. Treatment decisions should be made by a multidisciplinary team. Symptomatic plexiform neurofibromas and tumors with malignant imaging evidence require neurosurgical intervention. The goals of surgery include reducing tumor size, alleviating pain, and improving appearance. Postoperative functional rehabilitation exercises, long-term multidisciplinary follow-up, and psychosocial interventions are crucial for improving the quality of life for patients. Advanced imaging guidance systems and artificial intelligence technologies can help increase tumor resection rates and reduce recurrence. Conclusion: Neurosurgical intervention is the primary treatment for symptomatic plexiform neurofibromas and malignant peripheral nerve sheath tumors when medical treatment is ineffective and the lesions progress rapidly. Preoperative multidisciplinary assessment, intraoperative electrophysiological monitoring, and advanced surgical assistance devices significantly enhance surgical efficacy and safety. Future research should continue to explore new surgical techniques and improve postoperative management strategies to achieve more precise and personalized treatment for NF1 patients.

[Clinical features and surgical treatments of neurofibromas associated with neurofibromatosis type 1].

Objective: To explore the clinical features, surgical treatment, and effectiveness of neurofibromas associated with neurofibromatosis type 1 (NF1). Methods: A clinical data of 41 patients with NF1 admitted between December 2018 and April 2024 was retrospectively analyzed. There were 15 males and 26 females, with an average age of 27.5 years (range, 5-61 years). Only one type of neurofibroma existed in 3 patients and the rest of the patients had more than two types of neurofibromas. Fourteen patients had total resection of multiple cutaneous neurofibromas (CNF). Eighteen patients of diffuse neurofibromas underwent total, near-total, or subtotal resection. Among the 13 patients of localized nodular neurofibromas, 9 of benign tumors underwent total sub-capsular resection and 4 of malignant peripheral nerve sheath tumor (MPNST) underwent maginal resection, and only 1 underwent postoperative radiotherapy and chemotherapy. Among the 15 patients of plexiform neurofibromas (PNF), 5 patients underwent both superficial and deep PNF resection, 2 underwent the superficial PNF resection, and 8 underwent the large nodular lesions in the deep PNF resection. There were 8 MPNST, of which 7 cases underwent total sub-capsular resection and large tumor capsule resection under neurophysiological monitoring, and 1 case with the tumor located on the top of the head underwent wide resection and skin grafting. One patient underwent proton knife therapy after surgery, 2 patients did not receive radiotherapy, and the remaining patients received conventional radiotherapy. Results: All patients were followed up after surgery, and the follow-up time was 3-66 months, with an average of 25.0 months. Patients with CNF recovered satisfactorily after surgery, and there was no recurrence during follow-up. Patients with diffuse neurofibromas relieved preoperative symptoms after surgery. Three patients with diffuse neurofibromas located in the head and face recurred during follow-up. The patients with benign localized nodular neurofibromas recovered well after surgery, and only 1 patient had transient regional neuralgia after surgery. Among the patients with MPNST, 2 patients died of recurrence and lung metastasis, while the remaining 2 patients had no recurrence and metastasis during follow-up. All preoperative symptoms disappeared in patients with benign PNF, and no tumor recurrence was observed during follow-up. Two patients with PNF located in the brachial plexus had difficulty in shoulder abduction after surgery, 1 patient with PNF located in vagus developed hoarseness after surgery. Among the 8 patients with MPNST in PNF, 1 died of lung metastases and 1 died of systemic failure. The remaining 6 patients were in stable condition during follow-up, and no tumor recurrence or metastasis was observed. Conclusion: According to the clinical features of neurofibromas in patients with NF1, choosing appropriate surgical approaches can obtain good effectiveness. Because of the difficulty of completely resection, diffuse neurofibromas, especially those located in the head and face, are prone to recurrence after surgery. MPNST has the worst prognosis, high incidence of recurrence/metastasis, and short survival period. Total resection combined with radiotherapy can decrease local recurrence.

[Clinical experiences in precision treatment of giant plexiform neurofibromas of head, face, and neck].

Objective: To summarize the treatment strategies and clinical experiences of 5 cases of giant plexiform neurofibromas (PNF) involving the head, face, and neck. Methods: Between April 2021 and May 2023, 5 patients with giant PNFs involving the head, face, and neck were treated, including 1 male and 4 females, aged 6-54 years (mean, 22.4 years). All tumors showed progressive enlargement, involving multiple regions such as the maxillofacial area, ear, and neck, significantly impacting facial appearance. Among them, 3 cases involved tumor infiltration into deep tissues, affecting development, while 4 cases were accompanied by hearing loss. Imaging studies revealed that all 5 tumors predominantly exhibited an invasive growth pattern, in which 2 and 1 also presenting superficial and displacing pattern, respectively. The surgical procedure followed a step-by-step precision treatment strategy based on aesthetic units, rather than simply aiming for maximal tumor resection in a single operation. Routine preoperative embolization of the tumor-feeding vessels was performed to reduce bleeding risk, followed by tumor resection combined with reconstructive surgery. Results: All 5 patients underwent 1-3 preoperative embolization procedures, with no intraoperative hemorrhagic complications reported. Four patients required intraoperative blood transfusion. A total of 10 surgical procedures were performed across the 5 patients. One patient experienced early postoperative flap margin necrosis due to ligation for hemostasis; however, the incisions in the remaining patients healed without complications. All patients were followed up for a period ranging from 6 to 36 months, with a mean follow-up duration of 21.6 months. No significant tumor recurrence was observed during the follow-up period. Conclusion: For patients with giant PNF involving the head, face, and neck, precision treatment strategy can effectively control surgical risks and improve the standard of aesthetic reconstruction. This approach enhances overall treatment outcomes by minimizing complications and optimizing functional and cosmetic results.

Reduced PTPRS expression promotes epithelial-mesenchymal transition of Schwann cells in NF1-related plexiform neurofibromas.

Plexiform neurofibromas (PNFs) are a prevalent and severe phenotype associated with NF1, characterized by a high teratogenic rate and potential for malignant transformation. The growth and recurrence of PNFs are attributed to aberrant proliferation and migration of Nf1-deficient Schwann cells. Protein tyrosine phosphatase receptor S (PTPRS) is believed to modulate cell migration and invasion by inhibiting the EMT process in NF1-derived malignant peripheral nerve sheath tumors. Nevertheless, the specific role of PTPRS in NF1-derived PNFs remains to be elucidated. The study utilized the GEO database and tissue microarray to illustrate a decrease in PTPRS expression in PNF tissues, linked to tumor recurrence. Furthermore, the down- and over-expression of PTPRS in Nf1-deficient Schwann cell lines resulted in the changes of cell migration and EMT processes. Additionally, RTK assay and WB showed that PTPRS knockdown can promote EGFR expression and phosphorylation. The restoration of EMT processes disrupted by alterations in PTPRS levels in Schwann cells can be achieved through EGFR knockdown and EGFR inhibitor. Moreover, high EGFR expression has been significantly correlated with poor prognosis. These findings underscore the potential role of PTPRS as a tumor suppressor in the recurrence of PNF via the regulation of EGFR-mediated EMT processes, suggesting potential targets for future clinical interventions.

Giant Cerebriform Nevus Lipomatosus Cutaneous- Superficialis with Diffuse Lipomatosis: An Unusual Presentation on the Neck.

A 25-year-old man presented with gradually increasing swelling of 15 years' duration on the left side of his neck. There had been occasional foul-smelling discharge from the swelling. Local examination revealed an 8 cm × 5 cm oblong-shaped, yellowish to skin-colored, soft, -cerebriform swelling. There were multiple open comedones (Figure 1a). The surrounding skin had small and soft skin-colored papules. On palpation, there was no ulceration, tenderness, induration, or bag of worms. A scar from the past surgery was visible. Systemic examina- tion was unremarkable. The differential diagnosis demonstrated plexiform neurofibroma and nevus lipomatosus cutaneous superficialis (NLCS; Figure 2).

Selumetinib for children with neurofibromatosis type 1 and plexiform neurofibromas: A plain language summary of SPRINT.

WHAT IS THIS SUMMARY ABOUT?: This summary describes a publication about a study called SPRINT. The SPRINT study included 50 children with neurofibromatosis type 1 (NF1) and plexiform neurofibroma (PN) that could not be removed with surgery. PNs are tumors that grow along nerves and can cause various problems for children, such as pain, changes to appearance, and muscle weakness. In SPRINT, the study team wanted to learn whether a medication called selumetinib was able to shrink the PN caused by NF1 (also known as NF1-related PN), and if shrinking PNs helped relieve children of the problems caused by it. To assess how selumetinib might help, children had scans to measure the size of their PN, completed questionnaires, and had a variety of other tests done by their doctor. Their caregivers also completed questionnaires about their child. The children took selumetinib capsules twice a day on an empty stomach. WHAT WERE THE RESULTS?: The results showed that selumetinib was able to shrink the PN for most children (68%). The results also showed that the problems caused by the children's PNs mostly improved while on selumetinib treatment. SPRINT also showed that the side effects of selumetinib were mainly mild and could be managed by doctors. WHAT DO THE RESULTS MEAN?: Before SPRINT, there were not many treatment options for children with NF1 and PN as there were no medications that had been shown to shrink PN, and surgery was not always possible. SPRINT showed that this medication shrinks most PNs and could help children with NF1 and PN. In April 2020, selumetinib was approved by the US Food and Drug Administration (FDA) because of the results of SPRINT. Selumetinib was the first and, as of February 2024, is the only medicine that can be prescribed by doctors to help children with NF1-related PN. Clinical Trial Registration: NCT01362803 (SPRINT) (ClinicalTrials.gov).

Revisiting the NPcis mouse model: A new tool to model plexiform neurofibroma.

Neurofibromatosis Type I (NF1) is a rare genetic disorder. NF1 patients frequently develop a benign tumor in peripheral nerve plexuses called plexiform neurofibroma. In the past two decades, tissue-specific Nf1 knockout mouse models were developed using commercially available tissue-specific Cre recombinase and the Nf1 flox mice to mimic neurofibroma development. However, these models develop para-spinal neurofibroma, recapitulating a rare type of neurofibroma found in NF1 patients. The NPcis mouse model developed a malignant version of neurofibroma called malignant peripheral nerve sheath tumor (MPNST) within 3 to 6 months but intriguingly without apparent benign precursor lesion. Here, we revisited the NPcis model and discovered that about 20% display clinical signs similar to Nf1 tissue-specific knockout mice models. However, a systematic histological analysis could not explain the clinical signs we observed although we noticed lesions reminiscent of a neurofibroma in a peripheral nerve, a cutaneous neurofibroma, and para-spinal neurofibroma on rare occasions in NPcis mice. We also observed that 10% of the mice developed a malignant peripheral nerve sheath tumor (MPNST) spontaneously, coinciding with their earring tag identification. Strikingly, half of the sciatic nerves from NPcis mice developed plexiform neurofibroma within 1-6 months when intentionally injured. Thus, we provided a procedure to turn the widely used NPcis sarcoma model into a model recapitulating plexiform neurofibroma.

Precision oncology in neurofibromatosis type 1: quantification of differential sensitivity to selumetinib in plexiform neurofibromas using single-cell RNA sequencing.

PURPOSE: Selumetinib is an FDA-approved targeted therapy for plexiform neurofibromas in neurofibromatosis type 1(NF1) with durable response rates seen in most, but not all patients. In this proof-of-concept study, we demonstrate single-cell RNA sequencing(scRNAseq) as a technique for quantifying drug response to selumetinib at the single cell level. METHODS: scRNAseq data from neurofibroma biopsies was obtained from a public genomics repository. Schwann cell populations were identified through standard clustering techniques and single-cell selumetinib sensitivity was quantified on a scale of 0(resistant) to 1(sensitive) based on the expression pattern of a 500 gene selumetinib sensitivity signature from the BeyondCell sensitivity library. RESULTS: A total of seven plexiform neurofibromas were included in our final analysis. The median absolute number of Schwann cells across samples was 658 cells (IQR: 1,029 cells, Q1-Q3: 135 cells to 1,163 cells). There was a statistically significant difference in selumetinib sensitivity profiles across samples (p < 0.001). The tumor with the highest median selumetinib sensitivity score had a median selumetinib sensitivity score of 0.64(IQR: 0.14, Q1-Q3: 0.59-0.70, n = 112 cells) and the tumor with the lowest median selumetinib sensitivity score had a median score of 0.37 (IQR: 0.21, Q1-Q3: 0.27-0.48, n = 1,034 cells). CONCLUSIONS: scRNAseq of plexiform neurofibroma biopsies reveals differential susceptibilities to selumetinib on a single cell level. These findings may explain the partial responses seen in clinical trials of selumetinib for NF1 and demonstrate the value of collecting scRNAseq data for future NF1 trials.

Plexiform neurofibroma masquerading as a giant congenital melanocytic nevus.

A 4-month-old male presented for a large, hypertrichotic brown patch on the upper back with several scattered 0.5-1.5 cm, round to oval, brown macules and patches on the trunk and extremities. The lesion was initially diagnosed as a giant congenital melanocytic nevus based on clinical exam and histopathology with immunohistochemical stains. The patient was later diagnosed with neurofibromatosis type 1, and the lesion on the back developed a "bag of worms" texture consistent with a plexiform neurofibroma and found to harbor a pathogenic variant in the NF1 gene. This case highlights the diagnostic challenge of differentiating these lesions and their overlapping clinical and histopathological features.

A Population Pharmacokinetic Assessment of the Effect of Food on Selumetinib in Patients with Neurofibromatosis Type 1-Related Plexiform Neurofibromas and Healthy Volunteers.

Selumetinib is clinically used for pediatric patients with neurofibromatosis type 1 and symptomatic, inoperable plexiform neurofibromas. Until recently, selumetinib had to be taken twice daily, after 2 hours of fasting and followed by 1 hour of fasting, which could be inconvenient. This population analysis evaluated the effect of low- and high-fat meals on the pharmacokinetic (PK) parameters of selumetinib and its active metabolite N-desmethyl selumetinib. The dataset comprised 511 subjects from 15 clinical trials who received ≥1 dose of selumetinib and provided ≥1 measurable postdose concentration of selumetinib and N-desmethyl selumetinib. A 2-compartment model with sequential 0- and 1st-order delayed absorption and 1st-order elimination adequately described selumetinib PK characteristics. A 1-compartment model reasonably described N-desmethyl selumetinib PK characteristics over time simultaneously with selumetinib. Selumetinib geometric mean area under the concentration-time curve ratio (1-sided 90% confidence interval [CI] lower bound) was 76.9% (73.3%) with a low-fat meal and 79.3% (76.3%) with a high-fat meal versus fasting. The lower bound of the 1-sided 90% CI demonstrated a difference of <30% between fed and fasted states. Considering the flat exposure-response relationship within the dose range (20-30 mg/m2), the observed range of exposure, and the variability in the SPRINT trial, this was not considered clinically relevant.

Intraparotid plexiform neurofibroma: A rare diagnostic challenge.

Isolated intraparotid neurofibromas are exceptionally rare and often associated with neurofibromatosis type 1 (NF1). Diagnosing these tumors proves challenging because of the clinical resemblance to primary salivary gland masses. This case report details an 18-year-old with a painful, enlarging parotid mass, diagnosed through fine needle aspiration biopsy (FNAB) revealing myxoid stroma and spindle cells. Magnetic resonance imaging confirmed a plexiform neurofibroma involving the parotid gland and facial nerve. Histopathology validated the diagnosis, emphasizing the importance of cytological and radiological correlation. Notably, the absent NF1 association makes this case unique. Surgical excision with facial nerve reconstruction was performed, highlighting the complexity of managing such rare intraparotid neurofibromas. Awareness of this entity is crucial for accurate diagnosis and appropriate management.

Cutaneous toxicities of mitogen-activated protein kinase inhibitors in children and young adults with neurofibromatosis-1.

PURPOSE: Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder which commonly causes neoplasms leading to disfigurement or dysfunction. Mitogen-activated protein kinase inhibitors (MEKi) are generally well-tolerated treatments which target neural tumor progression in patients with NF1. However, cutaneous adverse events (CAEs) are common and may hinder patients' abilities to remain on treatment, particularly in children. We aim to characterize CAEs secondary to MEKi treatment in pediatric and young adult patients with NF1. METHODS: We reviewed institutional medical records of patients under 30 years with a diagnosis of "NF1," "NF2," or "other neurofibromatoses" on MEKi therapy between January 1, 2019 and June 1, 2022. We recorded the time-to-onset, type, and distribution of CAEs, non-cutaneous adverse events (AEs), AE management, and tumor response. RESULTS: Our cohort consisted of 40 patients with NF1 (median age, 14 years). Tumor types included low-grade gliomas (51%) and plexiform neurofibromas (38%). MEKi used included selumetinib (69%), trametinib (25%), and mirdametinib (6%). A total of 74 CAEs occurred, with 28 cases of acneiform rash (38%). Other common CAEs were paronychia, seborrheic dermatitis, eczema, xerosis, and oral mucositis. The most common treatments included oral antibiotics and topical corticosteroids. Most patients had clinical (stable or improved) tumor response (71%) while 29% had tumor progression while on a MEKi. There was no significant association between CAE presence and tumor response (p = 0.39). CONCLUSIONS: Improvement in characterization of MEKi toxicities and their management is important to develop treatment guidelines for pediatric and young adult patients with NF1 on MEKi therapy.

Efficacy and safety of selumetinib in patients with neurofibromatosis type 1 and inoperable plexiform neurofibromas: a systematic review and meta-analysis.

BACKGROUND: The approval of selumetinib in patients with neurofibromatosis type 1(NF1) and inoperable plexiform neurofibromas (PN) has reshaped the landscape of clinical management of the disease, and further comprehensive evaluation of the drug's efficacy and safety is needed. METHODS: Original articles reporting on the efficacy and safety of elumetinib in patients with NF1 were comprehensively searched in the Pubmed database, Embase database, Cochrane Library, and Web of Science database and screened for inclusion of studies that met the criteria. We pooled the objective response rate (ORR), disease control rate (DCR), disease progression rate (DPR), and the rate of improvement in PN-related complications using meta-analysis. The incidence of drug-related adverse events was also statistically analyzed. RESULTS: This study included 10 clinical trials involving 268 patients. The pooled ORR was 68.0% (95% CI 58.0-77.3%), the DCR was 96.8% (95% CI 90.8-99.7%) and the DPR was only 1.4% (95% CI 0-4.3%). The pooled improvement rate was 75.3% (95% CI 56.2-90.9%) for pain and 77.8% (95% CI 63.1-92.5%) for motor disorders. Most adverse events were mild, with the most common being gastrointestinal reactions (diarrhea: 62.5%; vomiting: 54.5%). CONCLUSION: Our study demonstrates that selumetinib is effective in patients with NF1 and PN, significantly improving the serious complications associated with PN as well as having tolerable toxicities. Our findings help to increase clinicians' confidence in applying selumetinib and promote the clinical adoption and benefit of the new drug.

C5aR plus MEK inhibition durably targets the tumor milieu and reveals tumor cell phagocytosis.

Plexiform neurofibromas (PNFs) are nerve tumors caused by loss of NF1 and dysregulation of RAS-MAPK signaling in Schwann cells. Most PNFs shrink in response to MEK inhibition, but targets with increased and durable effects are needed. We identified the anaphylatoxin C5a as increased in PNFs and expressed largely by PNF m acrophages. We defined pharmacokinetic and immunomodulatory properties of a C5aR1/2 antagonist and tested if peptide antagonists augment the effects of MEK inhibition. MEK inhibition recruited C5AR1 to the macrophage surface; short-term inhibition of C5aR elevated macrophage apoptosis and Schwann cell death, without affecting MEK-induced tumor shrinkage. PNF macrophages lacking C5aR1 increased the engulfment of dying Schwann cells, allowing their visualization. Halting combination therapy resulted in altered T-cell distribution, elevated Iba1+ and CD169+ immunoreactivity, and profoundly altered cytokine expression, but not sustained trumor shrinkage. Thus, C5aRA inhibition independently induces macrophage cell death and causes sustained and durable effects on the PNF microenvironment.

The PlexiQoL, a patient-reported outcome measure on quality of life in neurofibromatosis type 1-associated plexiform neurofibroma: translation, cultural adaptation and validation into the Dutch language for the Netherlands.

BACKGROUND: Half of the patients with Neurofibromatosis type 1 (NF1) develop one or more tumours called plexiform neurofibromas, which can have a significant impact on Quality of Life (QoL). The PlexiQoL questionnaire is a disease-specific QoL measure for adults with NF1-associated plexiform neurofibromas. The aim of this study was to adapt and validate a Dutch version of the PlexiQoL for the Netherlands. METHODS: The PlexiQoL was translated using the dual-panel methodology, followed by cognitive debriefing interviews to assess face and content validity. The psychometric properties were evaluated by administering the questionnaire on two separate occasions to a sample of adults with NF1 and plexiform neurofibromas. Feasibility was evaluated by the presence of floor/ceiling effects. Reliability was assessed by evaluating Cronbach's alpha coefficient and test-retest reliability, using Spearman's rank correlation coefficients. Mann-Whitney U tests were used to check for known group validity. The Nottingham Health Profile (NHP) questionnaire was used as comparator questionnaire to evaluate convergent validity. RESULTS: The translation and cognitive debriefing interviews resulted in a Dutch version of the PlexiQoL that reflected the original concept and underlying semantic meanings of the UK English version. Forty participants completed the validation survey. The Dutch PlexiQoL demonstrated excellent internal consistency (Cronbach's α 0.825) and test-retest reliability (Spearman correlation coefficient 0.928). The questionnaire detected differences in PlexiQoL scores between participants based on self-reported general health and disease severity. Convergent validity was confirmed for relevant NHP subsections. CONCLUSIONS: The Dutch PlexiQoL demonstrated excellent psychometric properties and can be reliably used to measure plexiform neurofibroma-related QoL in adults with NF1 in the Netherlands.

Written language achievement in children and adolescents with neurofibromatosis type 1 and Plexiform Neurofibromas.

Neurofibromatosis type 1 (NF1) is associated with below average writing achievement. However, little is known about specific aspects of written language impacted by NF1, changes in writing over time, and associations between cognitive aspects of the NF1 phenotype and writing. At three timepoints over six years, children with NF1 and plexiform neurofibromas (PNs) completed Woodcock-Johnson tests of writing mechanics (Spelling, Punctuation & Capitalization, handwriting), written expression of ideas (Writing Samples), writing speed (Writing Fluency), and tests of general cognitive ability, executive function, memory, and attention. Children (N = 76, mean age = 12.8 ± 3.4 years) completed at least one baseline writing subtest. Overall writing scores were in the Average range (M = 93.4, SD = 17.4), but lower than population norms (p = 0.002). Scores were highest on Writing Samples (M = 95.2, SD = 17.3), and lowest for Punctuation & Capitalization (M = 87.9, SD = 18.8, p = 0.034). Writing scores were mostly stable over time. Nonverbal reasoning was related to some tests of writing mechanics and written expression of ideas. Short-term memory and inattention explained additional variance in Writing Samples and Spelling. Poor handwriting was associated with writing content beyond the impact of cognitive factors. Children with NF1 and PNs may benefit from early screening and writing support. Interventions should address the contribution of both cognitive and handwriting difficulties in written language.