Anesthetic management of a patient with type 1 neurofibromatosis and an occult pheochromocytoma: a case report

Abstract Neurofibromatosis type 1 is a complex genetic disorder affecting multiple organ systems. Cardiovascular manifestations include hypertension, often associated with concomitant pheochromocytoma. We present a hypertensive crisis during induction of anesthesia in a patient with neurofibromatosis type 1, scheduled for abdominal myomectomy, which revealed an undiagnosed pheochromocytoma. The case highlights the importance of assessing all patients with neurofibromatosis type 1 for pheochromocytoma, because if it is left undiagnosed, it can be disastrous in the setting of anesthesia and surgery.

Debilitating pain and fractures: A rare case of Hypophosphatemic Osteomalacia with Concomitant vitamin D Deficiency in Neurofibromatosis Type 1 / Journal of the ASEAN Federation of Endocrine Societies

@#Hypophosphatemic osteomalacia is a rare form of metabolic bone disorder in neurofibromatosis type 1 (NF1). The exact disease mechanism of this disorder in NF1 is yet to be established. We present a 44-year-old female known to have NF1, who presents with debilitating bone pain, weakness and multiple fractures. Laboratory investigations showed persistent hypophosphatemia with renal phosphate wasting suggestive of hypophosphatemic osteomalacia. She also had concomitant vitamin D deficiency which contributed to the disease severity. Medical therapy with oral phosphate and vitamin D improved her symptoms without significant changes in fracture healing or phosphate levels.

Regulation of signaling pathways associated with cardiac valve development / 国际儿科学杂志

Congenital heart disease is the most common birth defect in China,of which heart valve dysplasia is an important phenotype.Heart valve development is an important process of embryonic development,which is regulated by a variety of signaling pathways.If the process of proliferation,differentiation or migration of endothelial cells and cardiomyocytes is abnormal,the heart valve will develop abnormally and the valvular heart disease may occur.Tissue explant systems and various animal model experiments have demonstrated that multiple signaling pathways interact to form a vast regulatory network that collectively regulates the development of heart valves.This review will highlight the nost intensively studied signaling pathways in epithelial-mesenchymal transition,including VEGF,NFATc1,Notch,Wnt,TGF-β,ErbB,and NF1 signaling pathways.

Regulation of signaling pathways associated with cardiac valve development / 国际儿科学杂志

Congenital heart disease is the most common birth defect in China, of which heart valve dysplasia is an important phenotype.Heart valve development is an important process of embryonic development, which is regulated by a variety of signaling pathways.If the process of proliferation, differentiation or migration of endothelial cells and cardiomyocytes is abnormal, the heart valve will develop abnormally and the valvular heart disease may occur.Tissue explant systems and various animal model experiments have demonstrated that multiple signaling pathways interact to form a vast regulatory network that collectively regulates the development of heart valves.This review will highlight the nost intensively studied signaling pathways in epithelial-mesenchymal transition, including VEGF, NFATc1, Notch, Wnt, TGF-β, ErbB, and NF1 signaling pathways.

Antiphospholipid syndrome and neurofibromatosis type I: a coincidence or new association? / Síndrome antifosfolípide e neurofibromatose tipo I: uma coincidência ou nova associação?

ABSTRACT - Numerous studies have reported on structural vascular anomalies and ischemia associated with neurofibromatosis type 1 that are thought to stem from dysfunction of neurofibromin, the neurofibromatosis type 1 protein. Documented cases of associated antiphospholipid syndrome fulfilling the accepted diagnostic criteria are exceptionally rare, with only three cases reported in the literature. Here, we report on a patient with neurofibromatosis type 1 and a history of spontaneous abortions presenting with sudden vision loss in the right eye and swelling of the optic nerve head. Fluorescein angiography indicated anterior ischemic optic neuropathy. Brain magnetic resonance imaging revealed findings consistent with left cavernous sinus meningioma. Serologic testing demonstrated persistently elevated anti-b2-glycoprotein antibodies. Her findings suggested antiphospholipid syndrome with concomitant clinical and laboratory evidence of antiphospholipid syndrome: frequent abortions, a vaso-occlusive episode, and persistently elevated antiphospholipid syndrome antibodies. To our knowledge, this case represents the first neuro-ophthalmic manifestation of antiphospholipid syndrome associated with neurofibromatosis type 1.

RESUMO - Inúmeros estudos têm relatado anomalias vasculares estruturais e isquemia associada com à neurofibromatose tipo 1 que, acredita-se, resultam da disfunção da neurofibromina, a proteína tipo 1 da neurofibromatose. Casos documentados de síndrome antifosfolípide associada que atendem aos critérios diagnósticos aceitos são excepcionalmente raros, com apenas três casos relatados na literatura. Aqui, relatamos um paciente com neurofibromatose tipo 1 e histórico de abortos espontâneos apresentando perda repentina de visão no olho direito e edema de cabeça do nervo óptico. A angiofluoresceínografia indicou neuropatia óptica isquêmica anterior. Ressonância magnética cerebral revelou achados compatíveis com meningioma do seio cavernoso esquerdo. O teste sorológico demonstrou anticorpos anti-b2 glicoproteína persistentemente elevados. Seus achados sugerem síndrome antifosfolípide com evidências clínicas e laboratoriais concomitantes de síndrome antifosfolipídica: abortos frequentes, episódio vaso-oclusivo e anticorpos antifosfolípides persistentemente elevados. Pelo nosso conhecimento, este caso pode representar a primeira manifestação neuro-oftálmica da síndrome antifosfolípide associada à neurofibromatose tipo 1.

Nf1 and BDNF Dysregulation in the Prefrontal Cortex Involved in the Pathogenesis of Attention Deficit Hyperactivity / 医学研究杂志

Objective To investigate the interaction between the Nf1 (Neurofibromin 1)and the BDNF (brain derived neurotrophic factor) in the mechanism of attention deficit hyperactivity disorder (ADHD).Methods Spontaneously hypertensive rats were chosen as the experimental group and WKY servesd as control.RT-PCR,Western-blot were used to detect the mRNA and protein expression levels of Nf1 and BDNF.To explore their relationship,BDNF expression levels were detected after Nf1 expression plasmid transferred and transfection in PC12H and CBRH-7919 cells.Results were quantified by Image-pro plus software.Results In the PFC of ADHD model rats SHR,Nf1 expression was abnormally degressive(P =0.000),in common with the expression of BDNF(P =0.000).Ectopic expression of Nf1 further encouraged the expression of BDNF (PC12H:P =0.000,7919:P ＜0.05).Conclusion Nf1 expression was significantly lower in PFC of SHR than control,and positively correlated with the levels of BDNF.These findings show that in the prefrontal cortex,Nf1-BDNF dysregulation may be involved in the pathomechanism of ADHD.

Hallazgos clínicos y oftalmológicos en niños con neurofibromatosis 1 / Clinical and ophthalmological findings in children with type 1 neurofibromatosis

Este trabajo tuvo por objetivos determinar la incidencia en nuestro medio de los criterios diagnósticos del National Institutes of Health (NIH) en niños con Neurofibromatosis 1 (NF1), comparar con estadísticas publicadas, analizar los hallazgos oftalmológicos, el valor de los estudios complementarios y establecer criterios de seguimiento. Métodos: Se trata de un estudio retrospectivo que incluyó 245 pacientes que ingresaron al Hospital de Pediatría Garrahan entre los años 1988 y 2010. Se diagnosticó NF1 en la primera consulta multidisciplinaria, utilizando los criterios de NIH, efectuándose en algunos niños neuroimágenes y potencial evocado visual (PEV). Resultados: El 92% de los pacientes presentó manchas café con leche; 40.8% neurofibromas, 75.5% nódulos de Lisch; 38.8% efeliloides; 16.3% glioma del nervio óptico; 16.3% displasia esquelética y 49% fueron hereditarios. Evidenciamos 1.76 miopías por cada hipermetropía. Conclusiones: Las frecuencias halladas coinciden con reportes previos, a excepción de las efeliloides, con incidencia menor. Realizamos de elección resonancia magnética nuclear (RMN), aún en pacientes asintomáticos, repitiéndolas bianualmente y examen oftalmológico cada seis meses hasta los ocho años. No indicamos actualmente PEV (AU)

The objective of this study was to determine the incidence of the National Institutes of Health (NIH) diagnostic criteria in children with Neurofibromatosis type 1 (NF1) in our setting, to compare them with the published statistical data, ophthalmological findings, the importance of complementary studies, and to establish follow-up criteria. Methods: We conducted a retrospective study including 245 patients that were admitted to the Pediatric Hospital Garrahan between 1988 and 2010. NF1 was diagnosed at the first multidisciplinary visit, using the NIH criteria. Neuroimaging and visual evoked potentials (VEP) were performed in some of the children. Results: 92% of the patients had café au laity spots; 40.8% neurofibromas; 75.5% Lisch nodules; 38.8% ephelides; 16.3% optic-nerve glioma; and 16.3% skeletal dysplasia. The disorder was hereditary in 49%. For each hypermetry,1.76 myopias were observed. Conclusions: These rates found were according to previous reports, except for ephelides, which were less common. Elective magnetic resonance imaging (MRI ) was performed, even in asymptomatic patients, and was repeated biannually and ophthalmological examination was done every six months until nine years of age. Currently, we do not indicate VEP

A clinicopathological and immunohistochemical study of malignant peripheral nerve sheath tumors.

Background: Malignant Peripheral Nerve Sheath Tumor (MPNST) is a rare aggressive sarcoma that develops within a peripheral nerve and forms a diagnostic challenge in view of its varied histomorphology. This short series highlights the clinicopathological spectrum of 11 cases of MPNST and the incidence of neurofibromatosis 1 (NF1) association. Methods: This retrospective and descriptive study on MPNST was done in the department of pathology, Kasturba medical college Mangalore (Manipal University), India over a period of three years from January 2008 to December 2010. Cases which were histopathologically diagnosed as MPNST were reviewed & immunostains was done where ever indicated to rule out the differentials. Results: A total of 11 cases of MPNST were documented with a wide age range of 17-85 years. Male:female ratio was 2.6:1. Extremities (63.64%) were found to be the most common site. Location wise most of the tumors were deep seated (63.64%) and maximum cases were high grade (54.55%). NF1 association was seen in 2 cases. Heterologous elements in the form of chondroid differentiation was seen in one case. Immunostain with S-100 was focally positive in all the cases. Conclusion: MPNST is a highly aggressive sarcoma with poor prognosis characterized by a challenge in its diagnosis as it has several mimics. Its diagnosis necessitates the incorporation of clinicopathological features and IHC with S-100 protein.

Malignant Peripheral Nerve Sheath Tumour of Small Intestine, an Unusual Tumour: A Case Report and Review of the Literature

Neurofibromatosis type-1 (NF1), also known as von Recklinghausen disease, is a common autosomal dominant condition. It is a multisystem disorder. Abdominal involvement in patients with NF1 has been described in the form of neurofibromas within the liver, mesentery, retroperitoneum and gastrointestinal (GI) tract. Involvement of bowel is rarely seen. Malignant peripheral nerve sheath tumour of small intestine is a rare entity with very few cases reported in literature. Surgery remains the only curative option. Chemotherapy may be used as an adjuvant for advanced diseases. We report a case of malignant peripheral nerve sheath tumour of small intestine which presented as acute intestinal obstruction.

Type I neurofibromatosis with pheochromocytoma.

Type 1 neurofibromatosis is a common neurocutaneous syndrome with various common and uncommon associations. The present case represents an uncommon association of type 1 neurofibromatosis and pheochromocytoma, which is probably due to mutation of NF-1 gene.

Report of a rare gingival neurofibroma in neurofibromatosis type 1 patient

Neurofibromatosis designates a group of neurocutaneous disorder that essentially affect the neural tissues cell growth. Neurofibromatosis type 1 (NF1), the most common amongst the variants accounts for about 90% of all cases. The expressivity of the disease is extremely variable, with oral involvement noted in 3.4 - 92% adults and 40% children. The diagnosis of the disease is principally based on clinical criteria. Treatment for neurofibromas is surgical excision. A rare case of gingival neurofibroma in NF1 patient is accounted in this case report.

A de novo em ~1.3 Mb microdeletion at 17q11.2 associated with Neurofibromatosis-Noonan syndrome

Introduction: Neurofibromatosis-Noonan syndrome is a clinical entity considered an extended Neurofibromatosis phenotype generally caused by different types of intragenic mutations at the NF1 gene. About 5%-10% of patients with neurofibromatosis diagnosis carry chromosomal microdeletions involving NF1, often presenting with a more severe phenotype than that observedin the patients carrying intragenic mutations; however, anticipating the presence of a deletion based only in the phenotype is not straightforward. Patient and Methods: Here we investigated by oligoarray-CGH (aCGH) the presence of a submicroscopic genomic rearrangement in a patientwith a clinical picture of Neurofibromatosis, and other characteristics compatible with Noonansyndrome. Results: The aCGH analysis revealed a germline de novo ~1.3 Mb microdeletion at 17q11.2 encompassing other coding genes besides the NF1 gene. Discussion: Up to now, thenumber of reported patients with Neurofibromatosis-Noonan syndrome carrying NF1 microdeletions is quite small. The continuous identification of patients carrying 17q11.2 deletions canhelp to establish a reliable genotype-phenotype relationship in this syndrome

Intracranial and Extracranial Fusiform Aneurysms in a Patient with Neurofibromatosis Type 1: A Case Report / 신경중재치료의학

Neurofibromatosis type 1 (NF-1) has a variety of localized or systemic manifestations. Among them, Cerebrovascular dysplasia can be very rare finding of neurofibromatosis which can be very rarely seen. Here we report a case of 17-year-old boy representing bilateral giant fusiform aneurysms of extracranial internal carotid arteries and intracranial aneurysms of left middle cerebral artery. He showed no related symptoms at all, but screening for vascular lesions and close monitoring is warranted in NF-1 patients considering that it can be symptomatic unexpectedly.

Mutational Analysis of the NF1 Gene in Two Families with Neurofibromatosis 1 Accompanied by Pheochromocytoma

Neurofibromatosis type 1 (NF1) is one of the most common autosomal dominant inherited disorders affecting the nervous system. NF1 is associated with mutations in the NF1 gene, which is located on chromosome sub-band 17q11.2 and contains 57 exons spanning approximately 300 kb of genomic DNA. NF1 is caused by a loss of function mutation of the NF1 gene, a tumor suppressor gene, which encodes for neurofibromin, a GTPase-activating protein (GAP) involved in the negative regulation of Ras activity. The GAP-related domain, which is encoded for by exons 20-27a, is one of the most important functional domains in neurofibromin. The cysteine-serine-rich domain has been recognized as an important functional domain in NF1-related pheochromocytomas. As the result of many genetic analyses of NF1-related pheochromocytomas, pheochromocytoma has generally been recognized as a true component of NF1. We recently experienced two families with NF1 accompanied by pheochromocytoma. The proband of family 1 is a 31-year-old female diagnosed with NF1 and pheochromocytoma. Gene analysis of the proband and her sister showed that the mutation of the NF1 gene (c.7907+1G>A) led to the skipping of exon 53 during NF1 mRNA splicing. The proband of family 2 is a 48-year-old male who was diagnosed with the same condition. Gene analysis demonstrated the mutation of the NF1 gene (c.5206-8C>G) with missplicing of exon 37. These novel germline mutations did not fall into the GAP-related nor the cysteine-serine-rich domains, but into the C-terminal area of the NF1 gene. This suggests that the correlation between the genotype and phenotype of NF1-related pheochromocytoma is somewhat difficult to characterize. Further studies will be necessary to confirm the function of the C-terminal area of the NF1 gene and its contribution to the development of NF1 and pheochromocytoma.

Malignant peripheral nerve sheath tumors: Clinicopathological profile of 63 cases diagnosed at a tertiary cancer referral center in Mumbai, India.

Background: A malignant peripheral nerve sheath tumor (MPNST) is a rare sarcoma, characterized by an aggressive course and forms a diagnostic challenge, in view of its varied histomorphology. The present study is a comprehensive analysis, including histopathological spectrum of 63 MPNSTs that forms a substantial study from an Indian perspective. Materials and Methods: Clinicopathological features of 63 MPNSTs, diagnosed during a period from January 2002 to December 2006, at a tertiary cancer referral center in Mumbai, India, were analyzed. Statistical analysis was carried out using SPSS (version 14) and STRATA. Difference in events was noted in 50 cases with selected variables. Disease free survival (DFS) was calculated by Kaplan-Meir analysis at the end of 1 year. Results: More cases were identified in > 30 years age (36 cases, 57.14%) group; in men (46 cases, 73%), and were deep-seated (38, 60.3%). Ten cases (15.9%) showed stigmata of multiple neurofibromatosis type 1. Average tumor (T) size was 9.9 cm, with 72.9% cases having T size > 5 cm. More cases were of high grade (56, 88.8%) and high stage (22, 34.9%). Histopathologically, most cases showed hypo- and hypercellular areas (marbleized appearance) of doubly indented spindle cells. Two cases showed epithelioid differentiation. Heterologous elements in the form of osteoid, chondroid, pigmented neuroectodermal (1 case), glandular (1 case) and rhabdomyoblastic differentiation (1 case) were identified in 14 cases (22.2%). S-100 protein positivity was noted in 38/54 cases (70.3%). Maximum cases (45, 71.4%) underwent surgery, including wide excisions and amputations (R0) in 20 cases, marginal excisions (R1) in 4, and intracapsular excision (R2) in 1 case. Nineteen cases underwent adjuvant treatment. A total of 29 cases (46%) showed recurrences and 22 (34.9%) showed multifocality and/or metastasis. Four patients succumbed to the disease in 1 year. The DFS was 53.1%. Cases ≤30 years of age (P- value = 0.007), T size > 5 cm, and with high grade (P = 0.18) and stage (P = 0.00) showed more recurrences, metastasis, and death. Conclusions: A MPNST has multifaceted histomorphology. Its objective identification necessitates the incorporation of clinicopathological features and IHC with S-100 protein. Younger age, high grade and stage, and increased T size significantly relate to aggressive disease. Wide excision forms the optimal treatment with options of adjuvant CT/RT in individual cases.

Gastric Outlet Obstruction due to Submucosal Neurofibromatous Proliferation of Duodenal Bulb in Neurofibromatosis Type 1 Patient

Neurofibromatosis type 1 (NF1; also known as von Recklinghausen's neurofibromatosis) is inherited in an autosomal dominant fashion, although it can also arise due to spontaneous mutation. Gastrointestinal involvement of NF1 is seen in 10% to 25% and causes symptoms in fewer than 5%. Histologically, the gastro intestinal (GI) manifestation of NF1 occurs in three forms: hyperplasia of the gut neural tissue, stromal tumors, and duodenal or periampullary endocrine tumors. A 31-year-old female, diagnosed with NF1, presented with poor oral intake and vomiting for 10 days prior to admission. Preoperative gastrofiberscopic finding was gastric outlet obstructing polypoid duodenal bulb lesion. The patient underwent hemigastrectomy with antecolic gastrojejunostomy due to gastric outlet obstruction. The final pathologic report was submucosal neurofibromatous proliferation with Brunner's gland hyperplasia located at the duodenal bulb in the NF1 patient. We report this case with a review of literatures.

Cariotipo de alta resolución en sangre periférica en la Neurofibromatosis 1 / High Resolution Karyotype in Peripheral Blood in Neurofibromatosis 1

La Neurofibromatosis tipo 1 (NF1) es uno de los desórdenes autosómicos dominantes más comunes y está causado por defectos en el gen NF1 situado en el cromosoma 17q11.2. Se realizó un estudio descriptivo y transversal en pacientes con NF1 en Pinar del Río durante el año 2005, con el objetivo de identificar en cariotipos de alta resolución defectos cromosómicos y relacionarlos con las características clínicas-radiológicas encontradas, seleccionando 42 pacientes con NF1, asociado a dismorfias, retraso mental, degeneración maligna, neurofibromas plexiformes y tumores del SNC. El 4,7% presentó cariotipo anormal. Las alteraciones estructurales que involucran el gen de la NF1 conllevan a una mayor severidad clínica de la enfermedad.

The Neurofibromatosis Type-1 (NF1) is one of the most common autosomal dominant disorders and it is provoked by a defect in the NF1 gene located in chromosome 17q11.2. A descriptive, cross-sectional study in patients carrying NF1 in Pinar del Rio was carried out during 2005 aimed at identifying the high resolution karyotypes of chromosomic defects to relate them to the clinical-radiologic features found, to perform it 42 patients carrying NF1 associated with dysmorphia, mental retardation, malignant degeneration, plexiform neurofibromas and tumors in the CNS were chosen. 4, 7% showed abnormal karyotype. The structural changes involving the NF1-gene lead to a greater clinical severity of the disease.

Neurofibromatose tipo 1: atualização / Neurofibromatosis type 1: update

JUSTIFICATIVA E OBJETIVOS: A neurofibromatose, descrita pelo patologista von Recklinghausen, é uma doença neurológica hereditária, sendo a neurofibromatose do tipo 1 (NF1) a forma mais freqüente das facomatoses autossômicas dominantes. O objetivo deste estudo foi discutir as características clínicas da NF1 e o manuseio multidisciplinar do paciente. CONTEÚDO: A NF1 é uma condição com complicações variadas, ocorrendo ao longo do curso da doença. Manchas café-com-leite, pseudo-artrose e neurofibromas plexiformes visíveis podem ser identificados durante a infância. Efélides, gliomas ópticos e grave escoliose ocorrem na primeira década de vida. Durante o curso, neurofibromas cutâneos e nódulos de Lisch da íris geralmente aparecem durante a segunda década. Embora os neurofibromas sejam uma característica benigna da doença, eles podem ser dolorosos, debilitantes, desfigurantes e podem crescer o suficiente para incluir regiões íntegras do corpo. Os diagnósticos diferenciais da NF1 incluem outras formas de neurofibromatose e doenças om manchas café-com-leite. O gene NF1 foi localizado no cromossomo 17 (17q11.2) e aproximadamente 50% dos casos representam mutações novas. O diagnóstico do defeito genético em pacientes com NF1 é difícil. O manuseio inclui o aconselhamento genético, exame oftalmológico regular e cuidadoso exame físico. Exames de imagem são indicados somente quando os pacientes estão sintomáticos. CONCLUSÃO: O diagnóstico da NF1 é feito com base no quadro clínico. Consultas médicas regulares a uma clínica multidisciplinar são essenciais. Nos primeiros 10 anos de vida, exames são recomendados. Não há tratamento efetivo para a NF1.(AU)

BACKGROUND AND OBJECTIVES: Neurofibromatosis, described by the pathologist von Recklinghausen, is a hereditary neurological disorder and the neurofibromatosis type 1 (NF1) is the most common form of autosomal dominant phakomatoses. In this review, we will discuss the clinical features of NF1 and the multidisciplinary management of the patient. CONTENTS: NF1 is a progressive condition with variable complications occurring over the time course of the disease. Café-au-lait spots, pseudarthrosis and externally visible plexiform neurofibromas can generally be identified during infancy. Freckling, optic gliomas and severe scoliosis occur within the first decade of life. On progression, cutaneous neurofibromas and iris Lisch nodules usually appear during the second decade. Although neurofibromas are a benign hallmark of the disease, they can be painful, debilitating, disfiguring and can grow large enough to encompass an entire body region. The differential diagnoses of NF1 include other forms of neurofibromatosis and conditions with café-au-lait spots. The NF1 gene was localized in the region 17q11.2 and approximately 50% of the cases represent new mutations. Molecular diagnosis of the genetic defect in NF1 patients is difficult. Management includes genetic counseling, regular eye examinations, and careful physical exams. Malignancy is primarily a complication of young adults with NF1. Imaging studies are indicated only when patients are symptomatic. CONCLUSION: The diagnosis of NF1 is made on the basis of clinical features. Regular medical appointments to a multidisciplinary clinic are essential. In the first 10 years of life, annual examinations are recommended. There is no effective treatment for NF1.(AU)

The Spectrum of NF1 Mutations in Korean Patients with Neurofibromatosis Type 1

Neurofibromatosis type 1 (NF1) is one of the most common autosomal dominant disorders in humans. NF1 is caused by mutations in the NF1 gene which consists of 57 exons and encodes a GTPase activating protein (GAP), neurofibromin. To date, more than 640 different NF1 mutations have been identified and registered in the Human Gene Mutation Database (HGMD). In order to assess the NF1 mutational spectrum in Korean NF1 patients, we screened 23 unrelated Korean NF1 patients for mutations in the coding region and splice sites of the NF1 gene. We have identified 21 distinct NF1 mutations in 22 patients. The mutations included 10 single base substitutions (3 missense and 7 nonsense), 10 splice site mutations, and 1 single base deletion. Eight mutations have been previously identified and thirteen mutations were novel. The mutations are evenly distributed across exon 3 through intron 47 of the NF1 gene and no mutational hot spots were found. This analysis revealed a wide spectrum of NF1 mutations in Korean patients. A genotype- phenotype correlation analysis suggests that there is no clear relationship between specific NF1 mutations and clinical features of the disease.