Neurofibromatosis is defined as a genetic disorder that leads to the formation of tumors on the nerve tissue. Tumors can develop at any location within the nervous system, even within the nerve, spinal cord, and even the brain.
The tumors, in this case, are usually non-cancerous (benign). However, some cases regarding the development of malignant tumors are rare.
This problem is usually diagnosed with a person in his childhood or during early adulthood.
Neurofibromatosis, which was first described in 1882 by Von Recklinghausen.
Neurofibromatosis is a genetic disease and also a neuroectodermal abnormality and by clinical manifestations of systemic and progressive involvement which mainly affect the skin, nervous system, bones, eyes, and possibly other organs.
The disease may manifest in several ways and it can vary from individual to individual.
Types of neurofibromatosis :
There are mainly three types of neurofibromatosis.
1.neurofibromatosis type 1 (NF1),
2.neurofibromatosis type 2 (NF2),
1.Neurofibromatosis type 1 (NF1):
Most adults with neurofibromatosis type 1 develop neurofibromas, which are noncancerous (benign) tumors that are usually located on or just under the skin.
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 cancer of blood-forming tissue (leukemia).
Neurofibromatosis type 1 mostly Beginning in early childhood.
Symptoms of NF 1:
Symptoms of NF1 include:
•multiple café-au-lait spots:
which are flat patches on the skin that are darker than the surrounding area? These spots increase in size and number as the individual grows older.
• Freckles in the underarms and groin typically develop later in childhood.
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.
•Some affected individuals also develop tumors that grow along the nerve, These tumors, called optic gliomas, may lead to reduced vision or total vision loss. In some cases, optic gliomas have no effect on vision.
•flat light brown spots on the skin,
groin area or ligaments on the side,
•formation of tumors on the optic nerve,
•soft bumps under the skin,
• larger than average head.
Symptoms of NF 2:
Symptoms of NF2 include :
such as cataracts,
•partial or total deafness,
•weakened arms and organs.
involves the formation of tumors within the Schwan cells or glial cells with acute pain and requires surgical treatment.
Causes of neurofibromatosis :
Neurofibromatosis is caused by genetic defects (mutations) that either is passed on by a parent or occur spontaneously at conception. The specific genes involved depend on the type of neurofibromatosis:
The NF1 gene is located on chromosome 17. This gene produces a protein called neurofibromin that helps regulate cell growth. The mutated gene causes a loss of neurofibromin, which allows cells to grow uncontrolled.
The NF2 gene is located on chromosome 22 and produces a protein called merlin (also called schwannoma), which suppresses tumors. The mutated gene causes a loss of merlin, leading to uncontrolled cell growth.
So far, two genes are known to cause schwannomatosis. Mutations of the genes SMARCB1 and LZTR1, which suppress tumors, are associated with this type of neurofibromatosis.
Risk factors of neurofibromatosis :
Autosomal dominant inheritance pattern
The biggest risk factor for neurofibromatosis is a family history of the disorder.
About half of people with NF1 and NF2 inherited the disease from the affected parent.
NF1 and NF2 are both autosomal dominant disorders, which means that any child of a parent with the disorder has a 50 percent chance of inheriting the genetic mutation.
The inheritance pattern for schwannomatosis is less clear.
Researchers currently estimate that the risk of inheriting schwannomatosis from an affected parent is about 15 percent.
Diagnosis of neurofibromatosis :
Diagnosis of a patient for neurofibromatosis involves:
• patient’s medical history and family history,
• physical examinations. Physical examination for growth and development, blood pressure monitoring of eye and ear examination, skeletal deformities,
•imaging tests like,
Patients with neurofibromatosis type 1 (NF1) should be checked with their doctor annually for a checkup.
For patients with neurofibromatosis type 2 (NF2) and to experience complete or partial hearing loss or tumor growth
, the doctor causes the problem. Can recommend surgical treatment to remove the tumor.
Stereotactic radiosurgery can help in cases where patients with NF2 suffer from hearing loss.
Patients are given radiotherapy and chemotherapy. If they are diagnosed with cancer.
Treatment of neurofibromatosis :
Treatment may include :
•Surgery to remove NF2 tumors completely
•Surgery for vestibular schwannomas does not restore hearing and usually reduces hearing. Sometimes surgery is not performed until a functional hearing is lost completely.
• Surgery may result in damage to the facial nerve and some degree of facial paralysis. Focused radiation of vestibular schwannoma carries a lower risk of facial paralysis than open surgery but is more effective in shrinking small to moderate tumors than larger tumors.
•Chemotherapy with a drug that targets the blood vessels of vestibular schwannoma can reduce the size of the tumor and improves hearing,
• but some tumors do not respond at all and sometimes respond only temporarily.
•Bone malformations can often be corrected surgically.
•surgery can also correct cataracts and retinal abnormalities. The pain usually subsides when tumors are removed completely.
How to prevent neurofibromatosis?
At the time of pregnancy if a couple want to their child will be free from neurofibromatosis then,
Couples with a family history of NF1 may wish to consider their options before having a baby. Your Gynecologist refers you to a genetic counselor to discuss your options.
These may include:
•having a child with a donor egg or sperm
•adopting a child
having a test during pregnancy :
•chorionic villus sampling or •amniocentesis to see if your baby will have NF1.
pre-implantation genetic diagnosis :
where eggs are fertilized in a laboratory and tested to make sure they don’t have the NF1 gene, before being implanted into the womb.