Question 1 of 10

    Neurofibromatosis Type 1 (NF 1)

    Neurofibromatosis[1]

    Neurofibromatosis type 1 (NF1) is an inherited systemic disorder that predominantly affects the skin, nervous system and musculoskeletal system. There is no cure for the disorder.

    The disease is promted by this process: hereditary.

    Presentation

    The clinical features of NF1 are often not present at birth or in early childhood and the diagnosis is made based on the history of the affected parent or sibling. In most cases, a child who is born to a family with NF1 and does not present with any clinical features by age 10, will most likely be unaffected by the disorder [1]. The presentation of a patient with NF1 is quite variable. In children, the most frequent initial finding is presence of multiple café-au-lait spots. These skin lesions may be present at birth and become more obvious with time. In most infants, the café-au-lait spots do increase in size and number with advancing age.

    Freckles in the inguinal or axillary region are very rarely seen at birth. However, as the child gets older and passes puberty, these skin lesions become more obvious. The neurofibromas are rarely seen in infants and young children. These lesions tend to occur past the age of puberty and become prominent by the adolescent years. The skin lesions initially start off as papules on the face, scalp, extremities and scalp. Some individuals may only have deeper neurofibromas that may only be felt via palpation. Some neurofibromas may not only be deep but also be locally invasive and produce pain with even mild palpation. The skin lesions often show rapid growth just after puberty or during pregnancy. Plexiform neurofibromas may also be associated with excess hair growth and darkening of skin. The growth of these neurofibromas can be rapid and that may be indicative of a malignant lesion.

    The optic nerve gliomas are usually low grade and occur in 1/5th of patients with NF1. These lesions are often silent but can present with symptoms in young children. Females are more likely to develop visual problems compared to males. Besides vision loss, others may develop peripheral visual field deficits, proptosis and difficulty discriminating color. The visual loss is often unilateral and often not correctable. Rarely a neurofibroma may encroach on nerve pathways of the hypothalamus-pituitary axis and present as precocious puberty in children.

    The Lisch nodules are usually not visible to the naked eye and require a slit lamp exam or use of an ophthalmoscope. Fundoscopic exam may reveal choroidal abnormalities. A variety of musculoskeletal defects may be seen in NF1 include bowing of the tibia/ulna, angulation and bowing of the long bones. Bony dysplasia of the sphenoid bone may be obvious but is often asymptomatic. Scoliosis may first become obvious in childhood and may be associated with kyphosis. Most individuals do not have progression of scoliosis but when it does progress it can be deforming and requires surgical intervention.

    At every visit, the blood pressure must be measured because of the possibility of primary hypertension or developing secondary hypertension from a pheochromocytoma or renal artery stenosis. In all children with NF1, head circumference needs to be monitored for the first few years of life. Head enlargement may occur rapidly and may be appear abnormal. Most individuals with NF1 tend to have short stature.

    Entire body system
    Coarctation of the Aorta
    • Coarctation of the aorta and other heart defects have also been reported (Friedman and Birch 1997 ; Lin et al. 2000 ).[link.springer.com]
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  • Skin
    Axillary Freckling
    • Axillary freckling is also known as the Crowe sign.[emedicine.medscape.com]
    • Freckling Neurofibromatosis Type 1 Café au Lait Macule Neurofibromatosis Type 1 Café au Lait Macule Neurofibromatosis Type 1 Optic Glioma Neurofibroma bright objects with cystic changes noted on MRI (T2 weighted imaging) in a patient with refractory[epilepsy.com]
    • freckling) and groin (inguinal freckling).[invitae.com]
    • Clinical diagnosis is based on the presence of two or more of the following findings: six or more CALMs (largest diameter 0.5 cm in prepubertal individuals, or 1.5 cm in postpubertal individuals); two or more NFs of any type, or one plexiform NF; axillary[intechopen.com]
    Cafe-Au-Lait Spots
    • Neurofibromatosis type I is characterized by cafe-au-lait spots, Lisch nodules in the eye, and fibromatous tumors of the skin.[flybase.org]
    • Having more than six cafe au lait spots is a strong indication of NF1.[mayoclinic.org]
    • Cafe-au-lait spots and freckles are not a problem and need no treatment.[childrensmn.org]
    • NF1 is characterized by “cafe-au-lait spots” (light brown skin patches) as well as neurofibromas (benign skin tumors).[weillcornellbrainandspine.org]
    • The most noticeable symptoms is abnormal pigmentation (cafe-au-lait spots) and/or freckling in atypical locations (armpits, groin).[raredr.com]
    Subcutaneous Nodule
    • Multiple subcutanous nodules (neurofibromas) were also present all over the body.[academic.oup.com]
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  • Workup

    The initial clue to the presence of NF1 is made from a clinical exam. Over the years, criteria have been established to help clinicians make an early diagnosis of NF1 [7]. The reason for the criteria is that not all clinical features appear until adolescence and often the diagnosis is delayed. For clinical diagnosis, there must be at least two of the seven criteria listed below.

    • Presence 2 or more axillary or inguinal freckles.
    • Presence of 6 or more café-au-lait spots or hyperpigmented skin lesions measuring 5 mm in diameter in prepubertal children and 15 mm postpubertal children.
    • At least 2 or more neurofibromas or one plexiform neurofibroma.
    • Optic nerve glioma.
    • Two or more Lisch nodules.
    • Presence of sphenoid dysplasia or classical long-bone angulation of bowing.
    • Presence of NF1 in a first-degree relative.

    However, in young children without clinical features, molecular testing may be of help. Today the NF1 gene can be tracked though linkage analysis and any mutation can be detected during the prenatal period via chorionic villus sampling or amniocentesis. Urinary levels of epinephrine and norepinephrine are measured if there is suspicion of a pheochromocytoma.
    Plain X-rays are used to detect musculoskeletal abnormalities. CT scans and MRI are also used to image the brain to detect optic gliomas, presence of hydrocephalus, spinal cord lesions, acoustic neuromas and pheochromocytomas [8].

    Treatment

    Neurofibromatosis has no cure. The majority of patients are monitored for life for development of complications resulting from the disease [9]. Patients need to be examined every 6-12 months for the following clinical features:

    • Checking skin to look for presence of any new neurofibromas or to determine if the older lesions are progressing in size.
    • Monitor blood pressure
    • Assessment of growth and development
    • A thorough eye exam
    • Assess for any bony alterations or worsening of any existing abnormalities
    • Evaluate for learning development

    At each visit the patient should be asked about any neurological symptoms like urinary or fecal incontinence, pain, tingling, weakness or paresthesia. Symptoms of spinal cord neurofibroma often develop slowly and are best treated when diagnosed early. Painful or ulcerated neurofibromas can be treated with chemotherapy and/or radiation. However, clinicians should try and avoid radiation therapy, as there is a potential for increased risk of secondary malignancies [10].

    Surgery

    Sometimes for isolated neurofibroma that are ulcerated, causing pain or loss of function, surgery can be used to excise the lesions. Neurofibromas may compress important nerves and affect vision or may be growing rapidly and invading important structures. These lesions usually required emergency surgical therapy. Because of the need to excise large lesions, consultation with a plastic surgeon is recommended to cover the resulting wound. In some patients who develop sudden progression of scoliosis or other bony defects, an orthopedic consultation is required.

    If pheochromocytoma is diagnosed, surgical excision is required. Some patients with hypertension due to renal artery stenosis may benefit from angioplasty or surgical repair of the renal artery lesion. Orthopedic intervention is indicated for rapidly progressive or severe bony defects. Laser is now used to treat the pigmented skin lesions but has not proven to be successful for café-au-lait spots.

    Prognosis

    Compared to the general population, the life expectancy of individuals with NF1 is slightly lower. Follow up studies show that on average NF1 individuals have 8-10 year decrease in their life span compared to the general population. However, it is important to know that patients with NF1 have a continuing risk of developing both malignant and benign tumors, which may occur on critical areas of the body and can severely impair function and quality of life [3] [4].

    • Gliomas are common in patients with NF1 and often occur on the spinal cord, optic nerve or in subcutaneous tissues. Even though these gliomas are usually of low grade and have a good prognosis, they often invade local tissue and management requires good clinical judgement to avoid complications [5].
    • Plexiform neurofibromas tend be multiple, diffuse and much larger than the usual neurofibromas. They are often locally invasive and difficult to treat. Surgical resection may be done for symptomatic lesions but post-surgical neurological deficits are common.
    • Malignant nerve tumors occur in about 10% of patients with NF1 and usually occur in peripheral nerves. The prognosis for large lesions is poor because the lesions are difficult to resect and often resistant to other treatments.
    • Even in the absence of neurofibromas, at least 1-3% of individuals with NF1 develop some type of sensory or polyneuropathy, which may present with pain, paresthesias and radiculopathy.
    • NF1 patients may also develop GI tract stromal tumors that often occur in the proximal small bowel. These tumors often present with GI bleeding or bowel obstruction, and require surgical intervention.
    • Some degree of learning deficits or behavior problems occur in nearly 2/5th of all patients with NF1. Besides intellectual impairment, many experience cognitive difficulties which limits their ability to attend school or work. There is a 30% prevalence of autism spectrum disorder in NF1 patients [6].
    • Scoliosis in NF1 is mild but in some children can progress rapidly and may require surgical intervention.
    • The limb dysplasias were once treated with below knee amputation but recent advances in orthopedic surgery has led to development of limb sparing procedures. Nevertheless, as the child grows the angulation or bowing of deformities continues to progress.
    • Premature osteoporosis is also identified early in some children with NF1, which may explain the bone angulation and bowing. Liberal use of vitamin D supplements are recommended.
    • Essential hypertension may occur at any age in NF1. In addition, renal artery stenosis and pheochromocytomas may also be other causes of secondary hypertension.
    • Arnold Chiari malformation type 1 is also seen in NF1 patients and a few need neurosurgical intervention to provide relief from hydrocephalus.

    Complications

    Acoustic Neuroma
    • Acoustic neuroma Surgery for acoustic neuromas does not always improve hearing, and it may worsen it.[medicalnewstoday.com]
    • Neurofibromatosis type 2 (NF2) is a hereditary condition most commonly associated with bilateral vestibular schwannomas, also known as acoustic neuromas.[cancer.net]
    • Neurofibromatosis type II, in which bilateral acoustic neuromas (tumors of the vestibulocochlear nerve or cranial nerve 8 (CN VIII) also known as schwannoma) develop, often leading to hearing loss.[en.wikipedia.org]
    • neuromas; these are benign tumors that develop from the balance and hearing nerves supplying the inner ear. or Family history of NF2 (first degree family relative) plus unilateral (on one side) vestibular schwannomas or any two of the following health[webmd.com]
    • Signs and symptoms of NF2 usually result from the development of benign, slow-growing tumors (acoustic neuromas) in both ears.[mayoclinic.org]
    Congenital Heart Disease
    • heart disease) McCune-Albright syndrome (large café-au-lait spots with irregular margins, polyostotic fibrous dysplasia) Noonan syndrome (short stature, unusual facies, pulmonic stenosis) A Noonan syndrome phenotype occurs in about 12% of patients with[en.wikibooks.org]
    • Children and adolescents with NF are more likely to suffer attention deficit hyperactivity disorder (ADHD); incidence is high, at around 40%. [ 10 ] Cardiovascular problems Congenital heart disease (pulmonary stenosis and hypertension) are associated[patient.info]
    • NF-Noonan Syndrome Noonan syndrome is characterized by short stature, characteristic facial features, a webbed neck and congenital heart disease (most commonly pulmonic stenosis).[link.springer.com]
    Glaucoma
    • […] stature Macrocephaly Cardiovascular: Hypertension (2-5%) Congenital heart defect (2%) Cognitive: Developmental delay Learning disabilities- hyperactivity and/or speech problems occur in 50% Mental retardation (8% of patients) Other-occasional: Syndactyly Glaucoma[en.wikibooks.org]
    Hydrocephalus
    • […] treatment of hydrocephalus.[ajnr.org]
    • Other features include hypertension, vasculopathy, intracranial tumors, malignant peripheral nerve sheath tumor (MPNST; see this term), and occasionally seizures or hydrocephalus.[orpha.net]
    • […] peripheral nerve sheath tumors arise in 2-4% of individuals Pheocromocytoma, rhabdomyoma, neuroblastoma (rare) Myelogenous leukemia (rare) Neurological: Headaches occur in 10% of patients Seizures and/or EEG abnormalities occur in 20% Seizures 6-7% Hydrocephalus[en.wikibooks.org]
    • Hydrocephalus is rare in NF1.[patient.info]
    • Rarely, underlying hydrocephalus is identified (Friedman and Riccardi 1999 ).[link.springer.com]
    Meningioma
    • , glioma, schwannoma, or cataract A single vestibular schwannoma diagnosed before age 30 and a meningioma, glioma, schwannoma, or cataract Multiple meningiomas and a unilateral, meaning affecting only 1 side, vestibular schwannoma diagnosed under age[cancer.net]
    • Schwannomatosis associated with multiple meningiomas due to a familial SMARCB1 mutation.[nf2is.org]
    • Unlike NF2, it rarely causes meningiomas.[mskcc.org]
    • NF2 includes schwannomas of multiple cranial and spinal nerves, especially the vestibular nerve, as well as other tumours such as meningiomas and ependymomas.[patient.info]
    • […] of NF2 (first degree family relative) plus unilateral (on one side) vestibular schwannomas or any two of the following health conditions: Glioma ( cancer of the brain that begins in glial cells, which are those that surround and support nerve cells) Meningioma[webmd.com]
    Mental Retardation
    • retardation (8% of patients) Other-occasional: Syndactyly Glaucoma Ptosis Pruritis Diagnostic Criteria [ edit ] (clinical diagnosis based on a number of clinical findings) NF1 is present in an individual who has two or more of the following signs: Six[en.wikibooks.org]
    • A much smaller percentage experience more significant cognitive difficulties such as mild or moderate mental retardation.[emedicine.medscape.com]
    • Some children also show signs of mental retardation and/or speech problems, as well as short stature, oversized head (macrocephaly), hypertension; and an increased risk of cancer (malignancy).[orthoinfo.aaos.org]
    • Working with women who have mental retardation: A genetic counselor’s guide .[link.springer.com]
    Multiple Sclerosis
    • Chang A, Nishiyama A, Peterson J, Prineas J, Trapp D ( 2000 ) NG2-positive oligodendrocyte progenitor cells in adult human brain and multiple sclerosis lesions.[jneurosci.org]
    • The range of multiple sclerosis associated with neurofibromatosis type 1 .[nature.com]
    Optic Nerve Glioma
    • To make the clinical diagnosis two or more of following are required 2 : 6 cafe au lait spots evident during one year two or more neurofibromas or one plexiform neurofibroma optic nerve glioma distinctive osseous lesion (such as sphenoid wing dysplasia[radiopaedia.org]
    • Adults may have a visually insignificant optic nerve glioma detected incidentally on a head imaging study.[emedicine.medscape.com]
    • However, evidence indicates that the risk for optic nerve glioma is lower in African Americans than in Caucasians and Hispanics.[emedicine.medscape.com]
    • Peripheral and central nervous system neoplasms occur frequently, especially optic nerve glioma and neurofibrosarcoma.[icd10data.com]
    Pheochromocytoma
    • Neoplasms It should come as no surprise that a disease due to inactivation of a tumour suppressor gene (see below) is also associated with increased incidence of numerous tumours 1-6 : pheochromocytoma malignant peripheral nerve sheath tumour (MPNST)[radiopaedia.org]
    • Benign adrenal gland tumor (pheochromocytoma).[mayoclinic.org]
    • […] developing tumors of the central and peripheral nervous system including plexiform neurofibromas (PN), dermal neurofibromas, optic pathway tumors, brain tumors, malignant peripheral nerve sheath tumors (MPNST), juvenile myelomonocytic leukemia, and pheochromocytomas[clinicaltrials.gov]
    • […] have a predisposition for developing the following types of tumors: Neurofibromas of the skin (cutaneous neurofibromas) Spinal and plexiform neurofibromas Malignant peripheral nerve sheath tumors (MPNST) Gliomas Gastrointestinal stromal tumors (GIST) Pheochromocytoma[mskcc.org]
    • High blood pressure may be caused by these rare, but treatable conditions: narrowing of the artery to the kidney (renal artery stenosis) tumor of the adrenal gland (pheochromocytoma) Other treatments may include: Problem Treatment ADHD Medicine and non-medicine[childrensmn.org]
    Plexiform Neurofibroma
    • Plexiform neurofibromas are far more difficult to treat.[orpha.net]
    • Patient’s father had similar café-au-lait spots and neurofibromas all over body with a plexiform neurofibroma ( Figure 1B ).[academic.oup.com]
    • Plexiform neurofibroma of the right thigh.[emedicine.medscape.com]
    • Plexiform neurofibromas can be difficult.[patient.info]
    • These malignancies frequently arise from large plexiform neurofibromas or extensive peripheral nerve lesions.[emedicine.medscape.com]
    Rhabdomyosarcoma
    • […] predisposition for developing the following types of tumors: Neurofibromas of the skin (cutaneous neurofibromas) Spinal and plexiform neurofibromas Malignant peripheral nerve sheath tumors (MPNST) Gliomas Gastrointestinal stromal tumors (GIST) Pheochromocytoma Rhabdomyosarcoma[mskcc.org]
    • […] suppressor gene (see below) is also associated with increased incidence of numerous tumours 1-6 : pheochromocytoma malignant peripheral nerve sheath tumour (MPNST) previously known as neurofibrosarcoma overal risk of developing a MPNST is 10% 7 Wilms tumour rhabdomyosarcoma[radiopaedia.org]
    • […] hormone producing organs located on top of each kidney) Leukemia, especially juvenile myelomonocytic leukemia (a blood cancer that affects young children) Breast cancer Gastrointestinal stromal tumors (tumors that form along the gastrointestinal tract) Rhabdomyosarcoma[chop.edu]
    • Among the tumors that do not originate in the neural crest are Wilms tumor, rhabdomyosarcoma, malignant nodular hidradenoma, and leukemia.[karger.com]
    • Embryonal Tumors Rhabdomyosarcomas are seen with disproportionately high frequency in individuals with NF1.[link.springer.com]
    Sarcoma
    • […] may involve multiple fascicles and branches of nerve. pNFs can occur in any part of the body and can grow throughout a person’s lifetime, often becoming disfiguring, disabling or deadly via compression of vital structures or conversion to a malignant sarcoma[n-tap.org]
    • We partner with oncologists and surgeons, including teams in neuro-oncology and sarcoma care, to offer the most up-to-date therapies and procedures.[mdanderson.org]
    • […] distinctive osseous lesion, including sphenoid wing dysplasia or thinning of the long bone cortex with or without pseudoarthrosis and (7) a first-degree relative with confirmed NF-1 (by the above criteria). 2 MPNST is the sixth most common soft tissue sarcoma[academic.oup.com]
    • Soft-tissue sarcomas: Overview of management, with a focus on surgical treatment considerations.[clevelandclinic.org]
    • Notable accomplishments include: Chairing the only neurofibromatosis research consortium in the world: the Department of Defense-funded Neurofibromatosis Clinical Trials Consortium Becoming one of the leading programs in the Sarcoma Alliance for Research[childrensnational.org]
    Scoliosis
    • A less common form of scoliosis that affects children with NF1 is dystrophic scoliosis.[orthoinfo.aaos.org]
    • In NF1 symptoms include light brown spots on the skin, freckles in the armpit and groin, small bumps within nerves, and scoliosis.[en.wikipedia.org]
    • Scoliosis is seen on clinical examination.[patient.info]
    • Enlargement and deformation of bones and curvature of the spine ( scoliosis ) may also occur.[webmd.com]
    • Scoliosis Lateral curvature of the spine, known as scoliosis, is common in NF1.[ctf.org]
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  • Etiology

    The precise cause of NF1 is not known but thought to be related to the protein molecule neurofibromin. Neurofibromin has many diverse functions and controls overgrowth of certain nerve and other cells. It appears that neurofibromin prevents uncontrolled growth of several cell types. When there is a decrease in neurofibromin, the clinical features of neurofibromatosis predominate.

    Epidemiology

    The incidence of NF1 is about 3 in every 10,000 births. However, these numbers are underestimates because there are some individuals who have no symptoms or clinical features of the disorder and never come to medical attention. NF1 occurs with equal frequency in all races. Newer data indicates that the risk for developing optic glioma is slightly less in African Americans compared to Hispanics and Caucasians. However, optic gliomas are more likely to occur in females compared to males. Similarly, the degree of scoliosis is more severe in young females compared to males.

    Sex distribution
    Age distribution

    Pathophysiology

    Neurofibromatosis is an inherited genetic disorder caused by a deletion or a mutation of the NF1 gene. The gene product of the NF1 gene known as neurofibromin, normally suppresses growth of nerve and many other related cells. When gene mutation occurs, there is uncontrolled overgrowth of certain nerve and other cells. Recent evidence indicates that the NF1 gene is localized the long arm of chromosome 17. Over the years, several hundred mutations of the gene have been identified in patients with NF1.

    Prevention

    There is no way to prevent NF1 because it is a genetically inherited disorder. However, early detection during pregnancy can help determine if the infant has the disorder. Families with NF1 should be referred for genetic counseling.

    Summary

    Neurofibromatosis type 1 (NF1) is an autosomal dominant medical disorder that primarily affects the skin, bone and nerve tissues. The disorder often presents with freckles in the axilla, café-au-lait spots (milky white lesions), bone dysplasia and growth of benign and malignant nerve tumors known as neurofibromas. Many individuals also develop essential or secondary hypertension due to renal artery stenosis or pheochromocytomas. The neurofibromas are usually multiple and often occur in critical areas of the body, leading to nerve compression. The one major difference between NF1 and NF2 is the former has a lower incidence of brain tumors, whereas patients with NF2 have fewer skin lesions but have a higher frequency of brain lesions like meningiomas and bilateral acoustic neuromas. 

    Patient Information

    Neurofibromatosis type 1 (NF1) is an inherited disorder that primarily affects the skin, bones and nerves. It is caused by a mutation of a gene on chromosome 17. The disorder is characterized by changes in skin coloring and the growth of tumors along nerves, brain, and in other body parts. When NF1 is diagnosed, the patient and the family should be referred to the national or local support group for both emotional support and continuous updates on the advances in treatment. Patients should be educated about possible symptoms that may require surgery. In addition, patients should be told about potential neurological symptoms that may indicate spinal cord compression. All patients and their families should be referred for genetic counseling should they desire to have children in future. Patients should be told to have continuous follow up with their healthcare provider and be cognizant of any new symptoms that may arise.

    Self-assessment

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    References

    1. Peltonen S, Pöyhönen M, Koillinen H, Valanne L, Peltonen J. [How to recognize neurofibromatosis?]. Duodecim. 2014;130(6):619-25.
    2. Abramowicz A, Gos M. Neurofibromin in neurofibromatosis type 1 - mutations in NF1gene as a cause of disease. Dev Period Med. 2014 Jul-Sep;18(3):297-306.
    3. Karajannis MA, Ferner RE. Neurofibromatosis-related tumors: emerging biology and therapies. Curr Opin Pediatr. 2015 Feb;27(1):26-33.
    4. Vranceanu AM, Merker VL, Park ER, Plotkin SR. Quality of life among children and adolescents with neurofibromatosis 1: a systematic review of the literature. J Neurooncol. 2015 Feb 7.
    5. Rolston JD, Han SJ, Cotter JA, El-Sayed IH, Aghi MK. Gangliogliomas of the optic pathway. J Clin Neurosci. 2014 Dec;21(12):2244-9.
    6. Schwetye KE, Gutmann DH. Cognitive and behavioral problems in children with neurofibromatosis type 1: challenges and future directions. Expert Rev Neurother. 2014 Oct;14(10):1139-52.
    7. Tadini G, Milani D, Menni F, Pezzani L, Sabatini C, Esposito S. Is it time to change the neurofibromatosis 1 diagnostic criteria? Eur J Intern Med. 2014 Jul;25(6):506-10.
    8. Zimmer A. Neurofibromatoses] Radiologe. 2013 Dec;53(12):1077-83.
    9. Hirbe AC, Gutmann DH. Neurofibromatosis type 1: a multidisciplinary approach to care. Lancet Neurol. 2014 Aug;13(8):834-43.
    10. Kahn J, Gillespie A, Tsokos M, Ondos J, Dombi E, Camphausen K, Widemann BC, Kaushal A. Radiation therapy in management of sporadic and neurofibromatosis type 1-associated malignant peripheral nerve sheath tumors. Front Oncol. 2014 Nov 17;4:324

    • An analysis of variation in expression of neurofibromatosis (NF) type 1 (NF1): evidence for modifying genes. - DF Easton, MA Ponder, SM Huson - American journal of , 1993 - ncbi.nlm.nih.gov
    • Is a plexiform neurofibroma pathognomonic of neurofibromatosis type I? - V Lin, S Daniel, V Forte - The Laryngoscope, 2009 - Wiley Online Library
    • An alternatively-spliced mRNA in the carboxy terminus of the neurofibromatosis type 1 (NF1) gene is expressed in muscle - DH Gutmann, LB Andersen, JL Cole - Human molecular , 1993 - Oxford Univ Press
    • A clinical study of type 1 neurofibromatosis in north west England - JM McGaughran, DI Harris, D Donnai - Journal of medical , 1999 - jmg.bmj.com
    • Aberrant Regulation Of Ras Proteins In Malignant-tumor Cells From Type-1 Neurofibromatosis Patients - TN Basu, DH Gutmann, JA Fletcher, TW Glover - 1992 - deepblue.lib.umich.edu
    • And pharmacokinetic study of the farnesyltransferase inhibitor tipifarnib in children with refractory solid tumors or neurofibromatosis type I and plexiform neurofibromas - BC Widemann, WL Salzer, RJ Arceci - Journal of clinical , 2006 - jco.ascopubs.org
    • Bilateral pheochromocytoma-ganglioneuroma of the adrenal in type 1 neurofibromatosis. - R Chetty, JD Duhig - The American journal of surgical pathology, 1993 - ukpmc.ac.uk
    • A clinical study of type 2 neurofibromatosis - DGR Evans, SM Huson, D Donnai, W Neary, V Blair - QJM, 1992 - Oxford Univ Press
    • An Absence of Cutaneous Neurofibromas Associated with a 3-bp Inframe Deletion in Exon 17 of the NF1 Gene (c. 2970-2972 delAAT): Evidence of a Clinically - M Upadhyaya, SM Huson, M Davies, N Thomas - The American Journal of , 2007 - Elsevier
    • A clinical study of type 2 neurofibromatosis - DGR Evans, SM Huson, D Donnai, W Neary, V Blair - QJM, 1992 - Oxford Univ Press
    • Absence of the greater sphenoid wing in neurofibromatosis type I: congenital or acquired: case report - R Macfarlane, AV Levin, R Weksberg, S Blaser - , 1995 - journals.lww.com
    • Absence of the greater sphenoid wing in neurofibromatosis type I: congenital or acquired: case report - R Macfarlane, AV Levin, R Weksberg, S Blaser - , 1995 - journals.lww.com
    • A clinical study of type 2 neurofibromatosis - DGR Evans, SM Huson, D Donnai, W Neary, V Blair - QJM, 1992 - Oxford Univ Press
    • A clinical study of type 1 neurofibromatosis in north west England - JM McGaughran, DI Harris, D Donnai - Journal of medical , 1999 - jmg.bmj.com
    • Brainstem tumors in patients with neurofibromatosis type 1 - PT Molloy, LT Bilaniuk, SN Vaughan, MN Needle - Neurology, 1995 - AAN Enterprises
    • An analysis of variation in expression of neurofibromatosis (NF) type 1 (NF1): evidence for modifying genes. - DF Easton, MA Ponder, SM Huson - American journal of , 1993 - ncbi.nlm.nih.gov
    • Association of childhood rhabdomyosarcoma with neurofibromatosis type I and birth defects - P Yang, S Grufferman, MJ Khoury - Genetic , 2005 - Wiley Online Library

    Media References

    1. Neurofibromatosis, Public Domain

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