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Neurofibromatosis genetic disorder causes development of neurofibromas which are tumors of the nervous tissue. Additionally, they cause other abnormalities of nerves, bones, spinal cord and skin.

Overview of neurofibromatosis genetic disorder

 

 

The tumors can develop on any nerve in the entire body. Both men and woman are at an equal risk of developing neurofibromatosis.
It can happen to anyone from any part of the world. It is an unpredictable condition of the nervous system.
 

What causes neurofibromatosis genetic disorder?

The faulty gene of the neurofibromatosis is either inherited or the condition develops as a result of the mutation of the gene in the egg or the sperm.

There are in total 23 sets of chromosomes present on each cell. One pair differs in male (XY) and female (XX) which determines the gender of the child. The remaining 22 sets of chromosomes are called autosomes.

Mutation may change the gene structure on one or more of these chromosomes.

In case of NF1, the faulty gene is located on chromosome number 17. For NF2, the chromosome number 22 bears the mutated gene.

 

Types and Symptoms of Neurofibromatosis

Scientists have divided neurofibromatosis genetic disorder mainly into three classes. These are as below:

  • Neurofibromatosis Type 1 or NF1
  • Neurofibromatosis Type 2 or NF2
  • Schwannomatosis

 

Neurofibromatoses Type 1

NF1 is the most commonly occurring type of neurofibromatosis. Although it is an inherited gene disorder it can even occur in families which have had no history of neurofibromatosis.

Symptoms of NF1 appear soon after birth of the child. They are visible in the form of spots and marks on the skin, and some type of bone deformities. Most of the symptoms are visible by the time the child is 10 years old.

There are two ways for this condition to occur. If either of the parents has this gene then the child is at 50% risk of developing the disease. The second way is that a certain gene may undergo a mutation that the child is born with this condition.
 

Symptoms of Neurofibromatoses Type 1

Common symptoms of NF1 include loss of hearing, learning disability, development of Lisch nodules and occurrence of freckles on the skin, especially in armpits and groin region. The Lisch nodules are tumors of the eye which appear on the iris. They are small in size and brown in color.

These nodules are characteristic to people suffering from NF1 type of neurofibromatosis genetic disorder.

Other symptoms include abnormal growth of the spine and the sphenoid bone (temple), plexiform neurofibroma and development of optic glioma.

Optic glioma is abnormal growth of the cells on the optic nerve and plexiform neurofibroma is the tumor that involves multiple nerves.
 

Neurofibromatoses Type 2

NF2 is not so common and it causes development of benign brain tumors in the 8th cranial nerve. The tumors are better known as the Schwannomas, usually the acoustic neuromas type, which leads to loss of hearing and dizziness.

Signs and Symptoms of Neurofibromatoses Type 2

Other signs and symptoms include pain and numbness in various areas of the face, balancing problems, frequent headaches and tinnitus. All these are result of the pressure exerted by the tumor on the nerves.

Most of the young patients of NF2 develop eye lesions and a type of cataract (juvenile cortical cataract).
 

Schwannomatosis

This type of neurofibromatosis is extremely rare and it develops due to mutation of genes on both the chromosomes, i.e. chromosome 12 and 22.

Signs and Symptoms of Schwannomatosis

If it develops, it causes chronic pain. Its signs and symptoms include occurrence of schwannomas (tumors developed from Schwann cells) on several parts of the body, weakness, numbness in several parts of body due to nerve damage and tingling.
Interestingly, those suffering from schwannomatosis neither have hearing loss nor have any learning disabilities.
 

Effect of Neurofibromatosis on the Nerves

Under normal conditions, the genes NF1and NF2 are responsible for production of proteins which aid in suppression of tumor cells.

NF1 directs the nerve cells, Schwann cells and oligodendrocytes (specialized cells of nervous system) to produce neurofibromin. It is a tumor suppressor.

When the gene structure changes, functioning of NF1 is affected. The cells are unable to produce functional neurofibromin. Hence, uncontrolled cell division and growth takes place which results in formation of neurofibromas (tumors). These tumors can develop anywhere on the nerves in the entire body.

The Schwann cells are also directed by NF2 to regulate and produce a protein called Merlin. Also known as Schwannomin, it is another tumor suppressant. The protein is responsible for regulation of communication between cells, cell structure and mobility. Due to mutation the protein produced is non-functional, allowing development of tumors.
 

Effects on Skin due to Neurofibromatosis

Skin experiences development of skin neurofibromas and café au lait spots. The café au lait spots are brown colored marks that may be visible on any part of the body. They may appear as birth marks or become visible by the age of 9 in children.

Though they do not cause any medical problem but with age, their number and size increases. Additionally, they become darker in appearance. They can even appear inside the mouth and on the tongue.

 

Effects on Bones due to Neurofibromatosis

The skeleton system is considerably affected by this autosomal genetic disorder. Patients develop kyphosis, spondylolisthesis, scoliosis and Tibial dysplasia.

Kyphosis, or the hunchback, is commonly seen in NF1 patients. The patients develop anteroposterior angulations of the upper spine. The curvature may vary from less than 50 degrees to more than 70 degrees.

Spondylolisthesis is another bone deformation in neurofibromatosis. In this, one of the vertebras either slips backward or forward with respect to the next vertebra.

Patients commonly show scoliosis in which they develop additional curves other than the natural curvature of the backbone.

Tibial dysplasia is yet another type of bone abnormality in patients of NF1, though it is rare. In this, the tibia bone in the spine is abnormally bent causing a permanent bowing position in the patient.

Shenoid dysplasia is the bowing of the legs due to thinning of the long bones. It is found in NF1 patients.

The treatment of neurofibromatosis is associated with treating of the signs and symptoms.

The life expectancy of the patients suffering from the disorder depends on many factors. For example, the patient can lead a normal life if treatment is effective on the symptoms but if the tumor develops that is not curable then things cannot be any positive.
 

Read More: Huntington's Disease: Progressive Neurodegenerative Genetic Disorder

Importance of Awareness Month

May Observances 2010 is an effort to create a global awareness about various type of health conditions and diseases.
Top medical and health care organizations are part of May Observances 2010. These include ace names like American Chiropractic Association (United States), National Stroke Association (United Kingdom), National Osteoporosis Foundation (UK), American Academy of Dermatology (US), Better Sleep Council (US), Hepatitis Foundation International (global) and many more prominent national and international associations.

The month focuses on imparting awareness on more than 30 types of disorders and diseases. To make things more understandable the event has been covered by dividing it into weekly and daily events.

For example, the last week of the month, i.e. from May 25th to May 31st is observed as the “Kidney Health Week”. Likewise, May 31st will be observed as the “World Tobacco Day”.

But the month of May focuses broadly on creating awareness about major and minor health problems like asthma and allergies, cancer, Lupus, hearing and speech, high blood pressure, better sleep, cystic fibrosis.

The information regarding the event is available online

Awareness is first step to prevention, and prevention is better than cure.

  • www2.wfubmc.edu/neuro/Diseases+and+Conditions/Genetic+Disorders/Neurofibromatosis.htm
  • www.saywhatclub.com/newsletter/JoanieE/nf2.html
  • www.nlm.nih.gov/medlineplus/ency/article/000847.htm
  • en.wikipedia.org/wiki/Neurofibromatosis_type_II
  • www.wrongdiagnosis.com/n/neurofibromatosis/causes.htm
  • www.wrongdiagnosis.com/s/schwannomatosis/symptoms.htm
  • webcache.googleusercontent.com/search?q=cache:CIcFbSKbbBoJ:emedicine.medscape.com/article/1260124-overview+changes+in+bones+due+to+neurofibromatosis&cd=1&hl=en&ct=clnk&gl=in
  • www.whathealth.com/awareness/may.html