Neurofibromatosis Type 1
Return to Library
What is neurofibromatosis type 1?Neurofibromatosis type 1 is a genetic condition characterized by skin pigment changes and tumors that grow along nerves in the skin, brain, and other parts of the body. The signs and symptoms of this condition vary widely among affected people. Beginning in early childhood, almost all people with neurofibromatosis type 1 have multiple cafe-au-lait spots, which are flat patches on the skin that are the color of coffee with milk. These spots increase in size and number as the individual grows older. Freckles in the underarms and groin typically develop later in childhood. Most adults with neurofibromatosis type 1 have neurofibromas, which are noncancerous (benign) tumors that are usually located on or just under the skin. These tumors may also occur in the spinal cord or along nerves elsewhere in the body. Some people with neurofibromatosis type 1 develop cancerous tumors that grow along nerves. These tumors, which usually develop in adolescence or adulthood, are called malignant peripheral nerve sheath tumors. People with neurofibromatosis type 1 also have an increased risk of developing other cancers, including brain tumors and leukemia (cancer of blood-forming tissue). During childhood, benign growths called Lisch nodules often appear in the colored part of the eye (the iris). Lisch nodules do not interfere with vision. Another type of tumor, called an optic glioma, can occur on the nerve leading from the eye to the brain. These tumors are usually benign, but can cause reduced vision or total vision loss. Additional signs and symptoms of neurofibromatosis type 1 include high blood pressure and skeletal abnormalities such as curvature of the spine (scoliosis). Most people with this condition have normal intelligence. Fewer than 10 percent are mentally retarded, but about half of affected children have learning disabilities. In some cases, people have features of both neurofibromatosis type 1 and another genetic condition, Noonan syndrome. Noonan syndrome is characterized by distinctive facial features, short stature, heart defects, and skeletal abnormalities. The combination of signs and symptoms of these two conditions is sometimes called neurofibromatosis-Noonan syndrome. Other affected individuals have features of neurofibromatosis type 1 with developmental delay and a heart defect called pulmonic stenosis. Together, these signs and symptoms are known as Watson syndrome. Researchers believe that neurofibromatosis-Noonan syndrome and Watson syndrome are variants of neurofibromatosis type 1 because the conditions are usually caused by mutations in the same gene. How common is neurofibromatosis type 1?Neurofibromatosis type 1 occurs in 1 in 3,000 to 4,000 people. What genes are related to neurofibromatosis type 1?Mutations in the NF1 gene cause neurofibromatosis type 1. The NF1 gene provides instructions for making a protein called neurofibromin. This protein is produced in nerve cells and in specialized cells surrounding nerves (oligodendrocytes and Schwann cells). Neurofibromin acts as a tumor suppressor, which means that it keeps cells from growing and dividing too rapidly or in an uncontrolled way. Mutations in the NF1 gene lead to the production of a nonfunctional version of neurofibromin that cannot regulate cell growth and division. As a result, tumors such as neurofibromas can form along nerves throughout the body. Researchers are not yet certain how mutations in the NF1 gene cause other features of neurofibromatosis type 1, such as cafe-au-lait spots. How do people inherit neurofibromatosis type 1?Neurofibromatosis type 1 is considered to have an autosomal dominant pattern of inheritance. People with this condition are born with one mutated copy of the NF1 gene in each cell. In about half of cases, the altered gene is inherited from an affected parent. The remaining cases are the result of new mutations in the NF1 gene, and occur in people with no history of the disorder in their family. Unlike most other autosomal dominant conditions, in which one altered copy of a gene in each cell is sufficient to cause the disorder, two copies of the NF1 gene must be altered to trigger tumor formation in neurofibromatosis type 1. A mutation in the second copy of the NF1 gene occurs during a person's lifetime in specialized cells surrounding nerves. Almost everyone who is born with one NF1 mutation acquires a second mutation in many cells and develops the tumors characteristic of neurofibromatosis type 1.
Source: National Institutes of Health
|
Free Neurofibromatosis Type 1 Articles |
- Studies from Hacettepe University, Department of Medical Biology have provided new information about neurofibromatosis
- New findings from Charite University in the area of nerve sheath tumors published
- Studies from Cardiff University yield new data on familial cancer
- Reports on neurofibromatosis findings from Columbus Children's Hospital provide new insights
- Study data from Massachusetts General Hospital update knowledge of nerve sheath tumors
- Study data from University of Florida, Medical Department update knowledge of nerve sheath tumors
- New findings from University of Pittsburgh in the area of behavior in children published
- New neurofibromatosis findings from Columbus Children's Hospital published
- Findings from University of Ulm in human genetics reported
- Reports from Dresden University of Technology, Department of Surgical Research highlight recent research in neurofibromatosis in children
- Researchers at La Sapienza University target medical genetics
- Reports from University Medical Center, Department of Nuclear Medicine add new data to research in neurofibromatosis prevention
- Research in the area of neurofibromatosis reported from Washington University, Medical Department
- Researchers from Harvard University, Harvard Cancer Center detail findings in cancer therapy
- Study findings from Charite University broaden understanding of life sciences
- Data on myelomonocytic leukemia genetics published by researchers at University of Freiburg, Division of Pediatric Hematology
- Report summarizes neurofibromatosis genetics study findings from New England Medical Center, Department of Pathology
- Reports from Kyushu University, Department of Orthopaedic Surgery highlight recent research in orthopedics
- New neurofibromatosis immunology study findings have been reported from University of Minnesota
- Studies from University of Edinburgh further understanding of nerve sheath tumors
- Findings from National Human Genome Research Institute broaden understanding of neurofibromatosis
- New neurofibromatosis study results reported from S.S. Ergun et al
- Study data from Inha University, Department of Emergency Medicine update understanding of neurofibromatosis
- Reports summarize vessel disease genetics study results from E. Ballabio and co-researchers
|
|
|
Researchers at Columbus Children's Hospital target neurofibromatosis
2007 DEC 17 -- "Neurofibromatosis type 1 ( NF1) is a single gene disorder associated with a high frequency of cognitive deficits and a complex cognitive phenotype. These cognitive deficits have been associated with focal areas of high signal intensity on T2 weighted MRI images but the relationship remains controversial," scientists writing in the Journal of Neurology Neurosurgery and Psychiatry report. "A cohort of 76 children with NF1 and 45 unaffected sibling controls ( aged 8 - 16 years) underwent extensive neuropsychological assessment, with the NF1 children having MRI examinations. The presence or number of T2 hyperintensities ( T2H) was not associated with cognitive dysfunction. However, the location of discrete ( well circumscribed) T2H in the thalamus was associated with severe and generalised cognitive impairment. More diffuse lesions in the thalamus were also associated with reductions in IQ but the effects were less marked compared with the discrete lesions. Comparing children with NF1 to their unaffected siblings revealed more subtle effects of the lesions on cognitive ability. T2H cannot be used in general as a radiological marker for cognitive deficits in children with NF1; however, lesions in the thalamus are strongly associated with cognitive impairment," wrote S.L. Hyman and colleagues, Columbus Children's Hospital. The researchers concluded: "It is possible that lesions in the thalamus in conjunction with more general thalamic hypometabolism may compound the level of thalamic dysfunction, resulting in cognitive deficits well beyond those produced by T2H in other regions." Hyman and colleagues published their study in the Journal of Neurology Neurosurgery and Psychiatry (T2 hyperintensities in children with neurofibromatosis type 1 and their relationship to cognitive functioning. Journal of Neurology Neurosurgery and Psychiatry, 2007;78(10):1088-1091). Additional information can be obtained by contacting K.N. North, Columbus Children's Hospital, School Clinic, Locked Bag 4001, Westmead, NSW 2145, Australia. The publisher of the Journal of Neurology Neurosurgery and Psychiatry can be contacted at: B M J Publishing Group, British Med Association House, Tavistock Square, London WC1H 9JR, England. Keywords: Australia, Westmead, Metabolism, Neurofibromatoses, Neurofibromatosis, Neurology, Neurosurgery, Psychiatry, Surgery, Urology, Wellness, Columbus Children's Hospital. This article was prepared by Pain & Central Nervous System Week editors from staff and other reports. Copyright 2007, Pain & Central Nervous System Week via NewsRx.com.
|
