Identification of potential common genetic modifiers of neurofibromas: a genome-wide association study in 1333 patients with neurofibromatosis type 1.

BACKGROUND: Neurofibromatosis type 1 (NF1) is characterized by the highly variable and unpredictable development of benign peripheral nerve sheath tumours: cutaneous (cNFs), subcutaneous (scNFs) and plexiform (pNFs) neurofibromas. OBJECTIVES: To identify neurofibroma modifier genes, in order to develop a database of patients with NF1. METHODS: All patients were phenotypically evaluated by a medical practitioner using a standardized questionnaire and the causal NF1 variant identified. We enrolled 1333 patients with NF1 who were genotyped for > 7 million common variants. RESULTS: A genome-wide association case-only study identified a significant association with 9q21.33 in the pNF phenotype in the discovery cohort. Twelve, three and four regions suggestive of association at the P ≤ 1 × 10-6 threshold were identified for pNFs, cNFs and scNFs, respectively. Evidence of replication was observed for 4, 2 and 6 loci, including 168 candidate modifier protein-coding genes. Among the candidate modifier genes, some were implicated in the RAS-mitogen-activated protein kinase pathway, cell-cycle control and myelination. Using an original CRISPR/Cas9-based functional assay, we confirmed GAS1 and SPRED2 as pNF and scNF candidate modifiers, as their inactivation specifically affected NF1-mutant Schwann cell growth. CONCLUSIONS: Our study may shed new light on the pathogenesis of NF1-associated neurofibromas and will, hopefully, contribute to the development of personalized care for patients with this deleterious and life-threatening condition.

Distinct Transcriptional Profiles in the Different Phenotypes of Neurofibroma from the Same Subject with Neurofibromatosis 1.

Neurofibromatosis 1 is a prevalent hereditary neurocutaneous disorder. Among the clinical phenotypes of neurofibromatosis 1, cutaneous neurofibroma (cNF) and plexiform neurofibroma (pNF) have distinct clinical manifestations, and pNF should be closely monitored owing to its malignant potential. However, the detailed distinct features of neurofibromatosis 1 phenotypes remain unknown. To determine whether the transcriptional features and microenvironment of cNF and pNF differ, single-cell RNA sequencing was performed on isolated cNF and pNF cells from the same patient. Six cNF and five pNF specimens from different subjects were also immunohistochemically analyzed. Our findings revealed that cNF and pNF had distinct transcriptional profiles even within the same subject. pNF is enriched in Schwann cells with characteristics similar to those of their malignant counterpart, fibroblasts, with a cancer-associated fibroblast-like phenotype, angiogenic endothelial cells, and M2-like macrophages, whereas cNF is enriched in CD8 T cells with tissue residency markers. The results of immunohistochemical analyses performed on different subjects agreed with those of single-cell RNA sequencing. This study found that cNF and pNF, the different neurofibromatosis phenotypes in neurofibromatosis 1, from the same subject are transcriptionally distinct in terms of the cell types involved, including T cells.

Intratemporal facial nerve neurofibroma causing facial paralysis in an infant: Case report and review of the literature.

This article describes the first recorded case of intratemporal neurofibroma in an infant. A literature review of all other existing cases of intratemporal neurofibroma is performed, finding that the majority of cases involve multiple segments and can be found in the mastoid segment most often. Most common symptoms described included facial paralysis, otalgia, and conductive hearing loss, respectively.

Neurofibroma: Case Series with Clinical Features and Recommendations.

Neurofibroma is an autosomal benign disorder. It can be localized, diffuse or invasive like plexiform neurofibroma that involves the nerves, muscle, tissues, skeleton. It represents itself as a destructive variant of neurofibroma, mostly present as orbital or periorbital neurofibroma or may be associated with autosomal dominant disease. Clinical diagnosis of neurofibromatosis (NF) according to National Institutes of Health (NIH) criteria should have more than two of the seven features including lisch nodules, cafe'- au-lait spots, plexiform neurofibroma, optic glioma, freckling, first degree relative with NF or dysplasia of cortical bones. However, proper early diagnosis is still crucial due to its various presentation such as cheek mass, painless swelling on skin, chalazion, intratracheal tumor, genital swelling or ptosis. It is reported that neurofibroma often represents as ocular or facial swelling. Here we are presenting features of neurofibroma of eight cases of patients from Civil Hospital, Karachi. These cases had main complain of overhanging skin mass mainly on orbital or periorbital region that damage the area and with poor daily activities. Multiple nodules on face and body along with them Cafe'-au-lait spots and lisch nodules were main signs. While, other signs i.e. ptosis, pterygium, telecanthus and muddy discoloration of conjunctiva need further evaluation for correlation with neurofibromatosis. Debulking surgery was planned for most of the cases but the huge disfigurement caused by overhanging skin mass and nodules made it a challenge for plastic surgeons to provide good outcomes with minimum damage. Keywords: neurofibroma; lisch nodules; ptosis; Cafe'-au-lait spot; periorbital; overhanging skin.

Perinatal folate levels do not influence tumor latency or multiplicity in a model of NF1 associated plexiform-like neurofibromas.

OBJECTIVE: In epidemiological and experimental research, high folic acid intake has been demonstrated to accelerate tumor development among populations with genetic and/or molecular susceptibility to cancer. Neurofibromatosis type 1 (NF1) is a common autosomal dominant disorder predisposing affected individuals to tumorigenesis, including benign plexiform neurofibromas; however, understanding of factors associated with tumor risk in NF1 patients is limited. Therefore, we investigated whether pregestational folic acid intake modified plexiform-like peripheral nerve sheath tumor risk in a transgenic NF1 murine model. RESULTS: We observed no significant differences in overall survival according to folate group. Relative to controls (180 days), median survival did not statistically differ in deficient (174 days, P = 0.56) or supplemented (177 days, P = 0.13) folate groups. Dietary folate intake was positively associated with RBC folate levels at weaning, (P = 0.023, 0.0096, and 0.0006 for deficient vs. control, control vs. supplemented, and deficient vs. supplemented groups, respectively). Dorsal root ganglia (DRG), brachial plexi, and sciatic nerves were assessed according to folate group. Mice in the folate deficient group had significantly more enlarged DRG relative to controls (P = 0.044), but no other groups statistically differed. No significant differences for brachial plexi or sciatic nerve enlargement were observed according to folate status.

Combined CDK4/6 and ERK1/2 Inhibition Enhances Antitumor Activity in NF1-Associated Plexiform Neurofibroma.

PURPOSE: Plexiform neurofibromas (PNF) are peripheral nerve sheath tumors that cause significant morbidity in persons with neurofibromatosis type 1 (NF1), yet treatment options remain limited. To identify novel therapeutic targets for PNF, we applied an integrated multi-omic approach to quantitatively profile kinome enrichment in a mouse model that has predicted therapeutic responses in clinical trials for NF1-associated PNF with high fidelity. EXPERIMENTAL DESIGN: Utilizing RNA sequencing combined with chemical proteomic profiling of the functionally enriched kinome using multiplexed inhibitor beads coupled with mass spectrometry, we identified molecular signatures predictive of response to CDK4/6 and RAS/MAPK pathway inhibition in PNF. Informed by these results, we evaluated the efficacy of the CDK4/6 inhibitor, abemaciclib, and the ERK1/2 inhibitor, LY3214996, alone and in combination in reducing PNF tumor burden in Nf1flox/flox;PostnCre mice. RESULTS: Converging signatures of CDK4/6 and RAS/MAPK pathway activation were identified within the transcriptome and kinome that were conserved in both murine and human PNF. We observed robust additivity of the CDK4/6 inhibitor, abemaciclib, in combination with the ERK1/2 inhibitor, LY3214996, in murine and human NF1(Nf1) mutant Schwann cells. Consistent with these findings, the combination of abemaciclib (CDK4/6i) and LY3214996 (ERK1/2i) synergized to suppress molecular signatures of MAPK activation and exhibited enhanced antitumor activity in Nf1flox/flox;PostnCre mice in vivo. CONCLUSIONS: These findings provide rationale for the clinical translation of CDK4/6 inhibitors alone and in combination with therapies targeting the RAS/MAPK pathway for the treatment of PNF and other peripheral nerve sheath tumors in persons with NF1.

Turner Syndrome and Neurofibromatosis 1: Rare Co-Existence with Important Clinical Implications.

A 16.5-year-old Indian female presented with secondary amenorrhoea, cubitus valgus, scoliosis and multiple lentigines on the face. Karyotyping revealed mosaic Turner syndrome (TS) with 45, X/46, X iXq. She also had multiple café-au-lait macules and axillary freckles but no neurofibroma and did not fulfil the classic criteria for diagnosis of Neurofibromatosis-1 (NF1). Many of her macules were smaller than 15 mm in diameter, which might be due to her hypoestrogenic state. However, exome-sequencing found a pathologic variant consistent with NF1. She was started on daily oral estrogen, and oral progesterone for 10 days every month with close monitoring for neurofibroma and/or glioma expansion. Co-occurrence of NF1 and TS is extremely rare, TS and NF1 can both affect growth and puberty, cause different cutaneous and skeletal deformities, hypertension, vasculopathy and learning disabilities. Our case highlights the need for genetic testing in some cases with NF1 who do not strictly fulfil the NIH diagnostic criteria. We also emphasize the need for close monitoring during therapy with growth hormone, estrogen and progesterone due to the potential risk of tumour expansion in NF1.

Ganglioneuroblastoma in a Child With Neurofibromatosis Type 1: A Case Report and Literature Review.

Neurofibromatosis type 1 (NF1) is a genetic condition commonly associated with a predisposition to tumor development. Affected individuals have an increased risk of benign and malignant tumors of the central and peripheral nervous system. Though pediatric patients with NF1 have an increased risk of tumors such as optic gliomas and neurofibromas during childhood, neuroblastic tumors are less often observed in this population. We report a rare case of a 5-year-old female with ganglioneuroblastoma intermixed and known history of NF1 and review the existing literature on the occurrence of ganglioneuroblastoma in pediatric patients with NF1.

Rapidly expanding giant neurofibroma of the back with intratumoral hematoma: a case report and literature review.

Neurofibromatosis type I is a common genetic disease that can lead to disfigurement, neurological and functional disorders. However, it is rare to meet the case which a huge mass is formed rapidly after neurofibroma ruptures. This case report describes a rare case of a 52-year-old female with a rapidly expanding mass on her back and mild anemia as the main symptoms. Physical examination showed a huge mass on the back and a surface ulceration with the diameter of 6 cm. Imaging examination revealed the abundant blood supply to the lesion. We performed preoperative arterial embolization, and surgical resection on the fifth day after embolization. After operation, proper blood transfusion and vacuum sealing drainage (VSD) were given. Through 9-months follow-up study, the incision of the patient recovered well and there was no sign of tumor recurrence. Therefore, this case report provides clinicians with valuable experience in the treatment for rapidly expanding neurofibroma.

Fatal Retroperitoneal Bleeding in Neurofibromatosis Type 1: A Clinically Occult Complication.

ABSTRACT: Neurofibromatosis type 1 (NF1) is a common, autosomal dominant neurocutaneous syndrome. The most frequent clinical manifestations include multiple neurofibromas, café-au-lait spots, dystrophic scoliosis, benign and malignant peripheral nerve sheath tumors, and paragangliomas. Neurofibromatosis type 1 vasculopathy is a less well-recognized constellation of vascular pathologies that can cause significant medical complications in patients with NF1. A rare manifestation of this process is neurofibroma infiltration of vasculature with resultant bleeding. The case presented herein illustrates a rare example of a massive fatal hemorrhage due to disruption of a large paraspinal artery in the setting of a diffuse, infiltrative neurofibroma. This case highlights the potential of benign neurofibromas to infiltrate major blood vessels, leading to extensive bleeding and death.

A case report of a 4-year-old girl with neurofibromatosis type 1.

Neurofibromatosis type 1 is a rare genetic disorder, which is a benign nerve tumor resulting from aberrant growth of the cells of nerve sheath. NF1 patients were associated with multisystem involvement, characterized by neurofibroma, of which 50% were associated with plexus neurofibroma. Characteristically benign plexiform neurofibromas can cause pain, disfigurement, compression and functional changes. Although plexiform neurofibroma is common in the head and neck, the orbital plexiform neurofibroma is rare and easily confused with other orbital tumors. There is no consensus with regard to the treatment strategy of plexiform neurofibromas, current treatment has remained largely surgical, but comes with a high recurrence rate after partial removal. We describe a case of a 4-year-old patient with orbital plexiform neurofibroma who has a 3-year history of ptosis in the right eye. At the begining, we misdiagnosed it as hemangioma. After surgical resection, it was confirmed as plexiform neurofibroma by histopathological examination. One year after surgery, the tumor recurred, so surgical resection was performed again, and the ptosis was corrected. After that, the patients were followed up and examined annually, and no recurrence was found so far. This case shows that an infant or a child present with unilateral eye swelling and ptosis of the upper eyelid should be evaluated for orbital neurofibroma.

Diagnostic and follow-up protocol for adult patients with neurofibromatosis type 1 in a Spanish reference unit.

Neurofibromatosis type 1 (NF1) is one of the most common genetic neurocutaneous disorders. The hallmark of this disease is skin lesions in the form of café-au-lait spots, ephelides, and the characteristic cutaneous neurofibromas. Other common manifestations include bone abnormalities, "NF1 vasculopathy," and neurocognitive disorders. In addition, patients are at an increased risk for a wide variety of malignant neoplasms, including the malignant transformation of plexiform neurofibromas. It is necessary to know the various clinical characteristics of this disorder and to provide an early, multidisciplinary follow-up and treatment approach in order to provide optimal care to these patients, who present with a multisystemic disease that is potentially severe. This review summarizes the diagnosis and main clinical characteristics and suggests a protocol for screening and follow-up of adult patients with NF1.

Intranodal Neurofibroma: A Case Report and Literature Review.

PURPOSE: To report a case of neurofibroma involving the lymph nodes and to perform a literature review on this topic. OBSERVATIONS: A 72-year-old woman with a history of neurofibromatosis and biopsy-proven malignant melanoma of the left forearm underwent wide local excision of the malignant lesion along with sentinel axillary lymph node biopsy. Histological examination of axillary nodes revealed diffuse neurofibromatosis within 2 lymph node capsules. A thorough review of the English literature pertaining to intranodal neurofibroma was performed by querying Google Scholar and PubMed. Only 5 cases of intranodal neurofibroma have been described until now. CONCLUSIONS AND IMPORTANCE: Neurofibroma involving the lymph nodes is rare and this is the first reported case that is shown to diffusely involve the intracapsular space. Furthermore, intranodal neurofibroma can represent a diagnostic pitfall in the evaluation of sentinel lymph nodes for metastatic melanoma.

[Neurofibromas in Type I Neurofibromatosis. Description of a clinical case and literature review]. / Neurofibromas en la Neurofibromatosis tipo I. Descripción de caso clínico y revisión de la literatura.

Neurofibromatosis type 1 (NF1) is the most frequent genodermatosis. Its cutaneous findings are key for early diagnosis, as they usually appear at early age. Café-au-lait macules are the most known cutaneous findings. Neurofibromas are the most frequent cutaneous tumors in patients with NF1, showing multiple clinical manifestations. They are classified as superficial and deep lesions, and su perficial neurofibromas are subdivided in cutaneous or subcutaneous. Some neurofibromas may be present since birth; however, most appear during adolescence. Neurofibromas constitute 2 out of 7 of the NIH criteria of Neurofibromatosis type 1. Most of them are benign, do not require treatment and their recognition allows an early diagnosis of the disease. OBJECTIVE: To describe and classify neu rofibromas associated with NF1 through a clinical case. CLINICAL CASE: 18-year-old male diagnosed since childhood with NF1 presents with multiple oval nodules on his face, occipital area, and wrist, multiple blue-red macules on his back and an asymptomatic pink plaque in his thigh. Ultrasound of the nodules was suggestive of neurofibromas and a skin biopsy of the lesions in the back and thigh were consistent with cutaneous neurofibromas. CONCLUSION: This case illustrates the varied clinical manifestations of neurofibromas in adolescence. Recognition of neurofibromas by the pediatrician, pediatric neurologist and/or dermatologist is crucial for the early diagnosis of NF1.

Measuring the Effect of Cutaneous Neurofibromas on Quality of Life in Neurofibromatosis Type 1.

OBJECTIVE: In order to explore the use of Skindex scoring in patients with neurofibromatosis type 1 (NF1) across multiple clinical sites and inform design of additional quality of life measures, we analyzed correlations between Skindex, site, and clinical measures for 79 patients with NF1 from specialized clinics in Sydney, Australia (Royal North Shore Hospital [RNS]) and Minneapolis, Minnesota (University of Minnesota [UMN]). METHODS: The relationship between clinical factors and Skindex scores were explored by clinic site and overall. RESULTS: A total of 40 participants were recruited from RNS and 39 from UMN. Female sex, total number of cutaneous neurofibroma (cNF), and whether cNF were present on the face correlated highly with Skindex and not Riccardi scores. The UMN site had lower average scores, but these differences were almost entirely removed after adjusting for age, sex, facial cNF, and total cNF number. CONCLUSIONS: The development of cNF in adolescence and adulthood in NF1 often leads to progressive disfigurement and discomfort and is among one of the most common reasons for patients to seek medical treatment. Skindex has been used to assess skin-related quality of life in NF1 previously but is not specific to NF1. These findings highlight the need for a low threshold for referral to dermatologists for all patients with NF1 regardless of the severity of disease. The finding that facial cNF and higher total number of cNF correlates with poorer skin-related quality of life may benefit design of more specific NF1 skin-related quality of life measures.