Jun 9, 2008

Neurofibromatosis

Neurofibromatosis is a genetically-transmitted disease in which nerve cells (Schwann cells) grow tumors (neurofibromas) that may be harmless or may cause serious damage by compressing nerves and other tissues.

Neurofibromatosis is inherited through a dominant gene. That means that if a child gets one gene for neurofibromatosis from one parent, and a normal gene from the other parent, that child will have neurofibromatosis. Therefore, if only one parent has neurofibromatosis, his or her children have a 50% chance of developing the condition as well. Disease severity in affected individuals, however, can vary (this is called incomplete penetrance).

Diagnosis and Treatment

Neurofibromatosis is usually diagnosed based on a combination of findings. A child must have at least two of the following signs to be diagnosed with NF1:

  • cafĂ©-au-lait spots of a certain number, size, and location
  • the appearance of two or more neurofibromas (often resembling pea-sized bumps on the skin)
  • Lisch nodules on the irises
  • an optic glioma (tumor along the main nerve of the eye that is responsible for sight)
  • certain skeletal abnormalities
  • a family member with NF1
  • freckling under the arms or in the groin

Tests like magnetic resonance imaging (MRI) and X-rays may be used to screen for tumors or evidence of skeletal problems. A child's head circumference will be measured because children with symptoms of NF can have a larger than normal head circumference for a given age. Blood pressure will be monitored. Doctors will also take a detailed personal history, looking for signs of learning difficulties at home or at school.

To diagnose NF2, doctors will check for any evidence of hearing loss. They'll order audiometry (hearing tests) as well as imaging tests to look for tumors in the nerves of the ears, spinal cord, or brain. They'll also determine if there's a family history of NF2.

Genetic testing is now available for people with a family history of either NF1 or NF2, though such testing is still not 100% sensitive. Amniocentesis can sometimes determine if a woman's unborn child has the condition.

Treatment for NF1 includes removal of the neurofibromas for cosmetic purposes, treating the complications (see below), and getting intervention for children with learning disabilities. Kids will be referred to appropriate medical specialists to monitor and treat any complications from the disease

click for more :
http://www.nlm.nih.gov/medlineplus/ency/article/000847.htm