35-507: NF1 may refer to: Neurofibromatosis type I , a genetic disorder that can cause tumors (can be cancerous) and other health effects such as vision impairment, imbowed legs, and joint pain. Neurofibromin 1 , a protein associated with the disorder above. Nuclear factor 1 , a transcription factor. NF-1, a variant of the AA-52 machine gun rechambered for 7.62 NATO ammunition. NF1 (aka NGSFF/M.3),
70-531: A gene located on chromosomal segment 17q11.2 on the long arm of chromosome 17 which encodes a protein known as neurofibromin (not to be confused with the disorder itself) which plays a role in cell signaling . The Neurofibromin 1 gene is a negative regulator of the Ras oncogene signal transduction pathway. It stimulates the GTPase activity of Ras . In 1989, through linkage and cross over analyses, neurofibromin
105-967: A 50% percent chance of passing the disorder to their offspring, but people can have a child born with NF-1 when they themselves do not have the condition. This is caused by a spontaneous mutation . The National Institutes of Health (NIH) has created specific criteria for the diagnosis of NF-1. Two of these seven "Cardinal Clinical Features" are required for positive diagnosis. There is practical flowchart to distinguish between NF1, NF2 and schwannomatosis. In addition to physical manifestations, patients with NF1 are at high risk of developing neurodevelopmental disorders , which result in learning difficulties, attention problems, and other behavioral or social challenges. Studies have shown that children with NF1 are particularly prone to being affected by conditions such as Attention Deficit Hyperactivity Disorder (ADHD) or Autism Spectrum Disorder (ASD), as well as psychological disorders such as anxiety or depression, highlighting
140-650: A bit of a mystery since they disappear over time (usually, by age 16), and they are not typically biopsied or resected. They may represent a focally degenerative bit of myelin . Within the CNS, NF-1 manifests as a weakness of the dura , which is the tough covering of the brain and spine. Weakness of the dura leads to focal enlargement due to chronic exposure to the pressures of CSF pulsation, and typically presents as paraesthesia or loss of motor or sensory function. It has been shown that dural ectasia occur near plexiform neurofibromas which may be infiltrative leading to weakening of
175-915: A diminished protective effect of gender against ASD symptoms, akin to other syndromic causes of ASD. Children with NF-1 may experience behavioral difficulties related to inattention, impulsivity, hyperactivity, and inflexibility. Studies have shown that clinical criteria for diagnosing ADHD are met by 23% to 50% of children with NF-1. Children with NF-1 may sometimes have attention difficulties without hyperactivity or behavioral problems. In such cases, attention deficits might go unnoticed without formal cognitive testing, although some children may have attention issues that, while not severe enough for an ADHD diagnosis, would still benefit from support. Individuals with neurofibromatosis type 1 often exhibit certain brain abnormalities known as T2 hyperintensities (visible on MRI scans), referred to as Unidentified Bright Objects (UBOs), which are located in specific brain regions such as
210-475: A few cosmetic effects. The other 20% have severe cases, with several symptoms that affect the person's quality of life. Even in this last group, symptoms are rarely life-threatening. The following is a list of conditions and complications associated with NF-1, and, where available, age range of onset and progressive development, occurrence percentage of NF-1 population, method of earliest diagnosis, and treatments and related medical specialties. The progression of
245-452: A plexiform neurofibroma. Biological females with NF also have a five-fold increased risk of breast cancer and may have an increased breast cancer related mortality. The median survival for breast cancer in people with NF was 5 years vs. the reported median survival of over 20 years in the general population using the SEER database. NF-1 is a microdeletion syndrome caused by a mutation of
280-556: A predisposition to develop glial tumors of the central nervous system, primarily optic nerve gliomas and associated blindness. Another CNS manifestation of NF-1 is the so-called "unidentified bright object" or UBO, which is a lesion which has increased signal on a T2 weighted sequence of a magnetic resonance imaging examination of the brain. These UBOs are typically found in the Cerebral peduncle , pons, midbrain, globus pallidus, thalamus, and optic radiations. Their exact identity remains
315-452: A second with collapsin response mediator protein . Together, likely with domains yet to be discovered, neurofibromin regulates many of the pathways responsible for overactive cell proliferation, learning impairments, skeletal defects and plays a role in neuronal development. The mutant gene is transmitted with an autosomal dominant pattern of inheritance, but up to 50% of NF-1 cases arise due to spontaneous mutation . The incidence of NF-1
350-543: A specification for internally mounted expansion cards [REDACTED] Topics referred to by the same term This disambiguation page lists articles associated with the same title formed as a letter–number combination. If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=NF1&oldid=1222348925 " Category : Letter–number combination disambiguation pages Hidden categories: Short description
385-502: Is 30% similar to proteins in the GTPase activating protein (GAP) family. This homologous sequence is in the central portion of neurofibromin and being similar to the GAP family is recognized as a negative regulator of the Ras kinase. Additionally, being such a large protein, more active domains of the protein have been identified. One such domain interacts with the protein adenylyl cyclase , and
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#1732859487324420-418: Is a common problem. Symptoms usually begin in young or mid-adult years. A neurofibroma is a lesion of the peripheral nervous system. Its cellular lineage is uncertain, and may derive from Schwann cells , other perineural cell lines, or fibroblasts . Neurofibromas may arise sporadically, or in association with NF-1. Neurofibroma conditions are progressive and include: Intracranially, NF-1 patients have
455-423: Is about 1 in 3500 live births. Prenatal testing may be used to identify the existence of NF-1 in the fetus. For embryos produced via in vitro fertilisation , it is possible via preimplantation genetic diagnosis to screen for NF-1. While the presence of NF-1 can be identified through prenatal testing the severity with which the condition will be expressed is impossible to determine. People with NF-1 have
490-656: Is associated with a primary problem in muscle function (myopathy). Clinical findings in people with NF-1 include: Studies in genetically modified mice have thus far confirmed that the NF1 gene is vital for normal muscle development and metabolism. Knockout of the NF1 gene in muscle results in deregulated lipid metabolism and muscle weakness. NF-1 is a disease in the RASopathy family of diseases, which include Costello Syndrome, Noonan Syndrome, and Cardiofaciocutaneous syndrome. The RASopathies also present with skeletal muscle weakness. It
525-405: Is different from Wikidata All article disambiguation pages All disambiguation pages Neurofibromatosis type I Neurofibromatosis type I ( NF-1 ), or von Recklinghausen syndrome , is a complex multi-system human disorder caused by the mutation of neurofibromin 1 (NF-1). NF-1 is a gene on chromosome 17 that is responsible for production of a protein (neurofibromin) which
560-507: Is likely that impaired muscle function in these disorders is linked to altered Ras/MAPK signalling, however, the precise molecular mechanisms remain unknown. The most common complication in patients with NF-1 is cognitive and learning disability. These cognitive problems have been shown to be present in approximately 90% of children and adults with NF-1 and have significant effects on their schooling and everyday life. These cognitive problems have been shown to be stable into adulthood mainly in
595-490: Is needed for normal function in many human cell types. NF-1 causes tumors along the nervous system that can grow anywhere on the body. NF-1 is one of the most common genetic disorders and is not limited to any person's race or sex. NF-1 is an autosomal dominant disorder, which means that mutation or deletion of one copy (or allele) of the NF-1 gene is sufficient for the development of NF-1 , although presentation varies widely and
630-481: Is often different even between relatives affected by NF-1 . As of 2015 , there are at least 100,000 people in the U.S. and about 25,000 people in the UK who have been diagnosed with NF. Common symptoms of NF-1 include brownish-red spots in the colored part of the eye called Lisch nodules , benign skin tumors called neurofibromas , and larger benign tumors of nerves called plexiform neurofibromas , scoliosis (curvature of
665-661: The Social Responsiveness Scale (SRS), and clinical observation tools as in the case of the Autism Diagnostic Observation Schedule (ADOS), suggesting that restricted repetitive behaviors in NF-1 autism may be qualitatively different or less severe than in idiopathic autism, and therefore may go undetected in ADOS assessments. Studies indicate that parent-reported scores on the autistic mannerisms subscale of
700-476: The 1.4 Mb type-1 microdeletion, and SUZ12 and SUZ12P for the 1.2 Mb type-2 microdeletion), are found in most cases. The neurofibromin gene was soon sequenced and found to be 350,000 base pairs in length. However, the protein is 2818 amino acids long leading to the concept of splice variants. For example, exon 9a, 23a and 48a are expressed in the neurons of the forebrain, muscle tissues and adult neurons respectively. Homology studies have shown that neurofibromin
735-517: The SRS questionnaire were notably high, with two-thirds of children with NF-1 + ASD scoring in the severe problem range. Regarding items assessing imagination and creativity, children with NF-1 + ASD exhibit similar levels of impairment as the autism group, while being significantly more affected than children with only ASD. Furthermore, no differences were observed between the groups on items measuring hyperactivity. Similarly, no evidence of group differences
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#1732859487324770-764: The cerebellum, brainstem, thalamus, and basal ganglia—areas involved in motor signal processing and cognitive functions. Some of these brain regions are also connected to attention-related networks, particularly those involved in cognitive flexibility and motor inhibition, which are essential for attention and behavior. It is well established that these networks are impaired in ADHD. Studies suggest that while ADHD symptoms may partially explain attention problems in NF-1, such as impulsivity, they do not fully account for other deficits like cognitive control. Children with NF-1 often exhibit impairments in planning, spatial working memory, and response inhibition, independent of ADHD, suggesting that
805-460: The condition is roughly as follows: Musculoskeletal abnormalities affecting the skull include sphenoid bone dysplasia, congenital hydrocephalus and associated neurologic impairment. Disorders affecting the spine include: Skeletal muscle weakness and motor control deficits Deficits in motor function in NF-1 have been long recognised and have been historically attributed to nerve dysfunction. In recent years however, studies suggest NF-1
840-486: The dura. Acetazolamide has shown promise as a treatment for this condition, and in very few cases do dural ectasia require surgery. People with NF1 are at increased risk for experiencing social and emotional difficulties such as; anxiety, depression, low self-esteem and/or body image, social withdrawal, difficulty forming interpersonal relationships, behavioural problems, and difficulties in school. People with NF1 are much more likely to experience suicidal thoughts than
875-454: The fact that genetic diagnosis has been used only in recent years, in the past NF-1 was in some cases confused with Legius syndrome , another syndrome with vaguely similar symptoms, including cafe-au-lait spots. NF-1 is an age-specific disease; most signs of NF-1 are visible after birth (during infancy), but many symptoms of NF-1 occur as the person ages and has hormonal changes. NF-1 was formerly known as von Recklinghausen disease, after
910-477: The general population. One study found that 45% of people with NF had suicidal thoughts compared to 10% of a healthy control group. Another study found that 46.5% were of people with NF1 were found to have at least one psychiatric comorbid diagnosis. Children and adults with NF-1 often have Autism and/or ADHD . Children diagnosed with NF-1 may experience delayed or precocious puberty. Recent studies have correlated precocious puberty in individuals with NF-1 with
945-568: The impact of ADHD on their attention and executive functioning is limited. Although ADHD prevalence is a key factor in NF-1 cognition studies, comparisons between children with NF-1 and ADHD and those without ADHD have not consistently shown clear differences. This creates confusion regarding how to differentiate the effects of NF-1 and ADHD on cognition. Moreover, focusing on ADHD symptoms might obscure attention issues that are specifically associated with NF-1. Friedrich Daniel von Recklinghausen Too Many Requests If you report this error to
980-1013: The importance of multidisciplinary evaluation and care for these patients. A significant number of children with NF-1 exhibit symptoms commonly associated with Autism Spectrum Disorder (ASD), which can impact daily functioning. These symptoms may include difficulties with flexibility and transitions, repetitive behaviors, challenges in social communication, social awareness, and adaptability. Some studies have identified subtle but significant differences between ASD symptomatology in individuals with NF-1 and those with idiopathic autism. These differences include stronger eye contact, fewer repetitive behaviors, and more pronounced autistic mannerisms compared to non-syndromic ASD. Enhanced language skills have also been noted in this population. More than 90% of children with ASD + NF1 demonstrate clinically significant challenges in interpreting social signals and social communication during interactions. Discrepancies have been noted between parent-report questionnaires, such as
1015-502: The mid 20s to early 30s and do not get worse unlike some of the other physical symptoms of NF-1. The most common cognitive problems are with perception, executive functioning and attention. Disorders include: The primary neurologic involvement in NF-1 is of the peripheral nervous system, and secondarily of the central nervous system. Schwannomatosis is a rare condition defined by the presence of multiple benign tumors of nerves that are frequently very painful. In addition to pain, weakness
1050-424: The presence of optic pathway tumours. Furthermore, the heights of children affected by NF-1 have been shown to increase normally until puberty, after which increases in height lessen when compared to healthy counterparts. This eventually causes a shorter stature than expected in individuals with NF-1. Cancer can arise in the form of malignant peripheral nerve sheath tumor resulting from malignant degeneration of
1085-602: The researcher who first documented the disorder, Friedrich Daniel von Recklinghausen . The severity of NF-1 varies widely, and little is known about what causes a person to have more severe or less severe symptoms. Even within the same family (as there is a 50% chance that a parent will pass their condition to their offspring), levels of severity can vary enormously. 60% of people with NF-1 have mild cases, with few symptoms that have very little effect in their day-to-day lives. About 20% of people with NF-1 have what are considered moderate cases, with several symptoms that usually have
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1120-445: The spine), learning disabilities , vision disorders , mental disabilities, multiple café au lait spots and epilepsy . While some people have major complications, others with the condition can lead productive and full lives. NF-1 is a developmental syndrome caused by germline mutations in neurofibromin , a gene that is involved in the RAS pathway ( RASopathy ). Due to its rarity, and to
1155-404: The two syndromes that influence the presentation of ASD symptoms. Due to their fewer observed repetitive behaviors and improved eye contact, these children may not exhibit the typical characteristics of idiopathic autism in clinical settings, increasing the likelihood that they will be overlooked by clinicians. Unlike idiopathic ASD, both males and females seem to be equally affected, indicating
1190-412: Was found for the anxiety item, which is also associated with certain genetic disorders, such as Fragile X syndrome and Cornelia de Lange syndrome . Research suggests that Neurofibromatosis Type 1 and Tuberous Sclerosis (TSC) exhibit similarities in the symptomatology associated with Autism Spectrum Disorder. These findings may indicate the existence of shared neurobiological characteristics between
1225-463: Was localized to chromosome 17. It was localized to the long arm of chromosome 17 by chance when researchers discovered chromosome exchanges between chromosome 17 with chromosome 1 and 22. This exchange of genetic material presumably caused a mutation in the neurofibromin gene, leading to the NF1 phenotype. Two recurrent microdeletion types with microdeletion breakpoints located in paralogous regions flanking NF1 (proximal NF1-REP-a and distal NF1-REP-c for
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