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Neurofibromatosis Type 1. Bennett Avram Heyman. Neurofibromatosis Type 1 Other names include:. NF1 Von Recklinghausen Disease Peripheral NF Neurocutaneous Disorder Phakomatoses. Mode of Inheritance . NF1 is a genetic disorder, and not a chromosomal disorders
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Neurofibromatosis Type 1 Bennett Avram Heyman
Neurofibromatosis Type 1Other names include: • NF1 • Von Recklinghausen Disease • Peripheral NF • Neurocutaneous Disorder • Phakomatoses
Mode of Inheritance • NF1 is a genetic disorder, and nota chromosomal disorders • NF1 can be found on the 1st to the 22nd chromosome, but not the 23rd (sex chromosome) • NF1 is a dominant disorder • NF1 can also be inherited due to spontaneous mutation • In the general population, 1 in 7000 children develop NF1. Because it is dominant, one carrier parent will give the child a 50% of inheritance, and if both parents are carriers, the child will have a 100% of inheritance
The father is heterozygous (Nn) and is affected with NF1. The mother is homozygous recessive (nn) and is therefore not affected with NF1. This means that there is a 50-50 chance of an affected parent having a child with NF1. N n Nn nn n Nn nn n Punnett Square
Pedigree • Below is a pedigree showing the same scenario as the Punnett Square, above.
Symptoms of NF1 • Cafe-au-lait spots on or under the skin • Scoliosis • Enlargement of bones • Deformation of the bones • Benign tumors, with the potential to become cancerous, occasionally in the brain, spine, or cranial nerves. • About 50% of cases have learning disorders • Iris nevi (clumps of pigment in the colored part of the eye) • Freckling where skin meets skin ( underarm, groin, under the breasts) • Early or delayed puberty • Speech impediment • Visual impairment • Seizures • Headaches • High Blood pressure
Detection • The main method of detection for NF1 is by paying attention to the signs and symptoms. Some key signs are multiple tumors, lots of freckles where skin meets skin, and six or more Café-au-lait spots.
Diagnostic Testing • There are several genetic test that can be done. These tests involve testing the DNA and looking for mutations or irregularities. The main way to diagnosis, however, is by studying the family history and observing the symptoms.
Prognosis • With NF1, most people live a relatively normal life. However, they live on average 54-60 years compared to the average of 70 years. • NF1 is primarily treated by controlling the symptoms.
Additional Health Problems • Scoliosis • Benign tumors with the potential to become malignant • Mental deficiency • Visual impairment • Speech impairment • Early or delayed puberty • Deformed of enlarged bones • Headaches • Large head • High blood pressure • Epilepsy (Rare)
Treatment • The main form of treatment is to control the symptoms. This includes removing tumors and repairing bone deformities.
Genetic Counseling • Upon visiting a genetic counselor, you will be tested to see if you or your spouse are a carrier for NF1. If one or both of you are found to be carriers, you will be presented with the necessary information for planning a future with children if you choose to have any. Some information that will be told to you is the likelihood of having and affect child, between 25% and 100%. You may also discuss alternate options for having children, such as adoption.
Above are some common bone deformities associated with NF1. Note the curvatures of the long bones.
Additional Interesting Facts • Chromosome 17 is often affected. This chromosome contains a tumor suppressor that when affected does not function properly.
Credits • http://www.ctf.org/ • http://www.nfinc.org/nf1.shtml • http://www.bcnf.bc.ca/whatis-dc.php • http://ninds.nih.gov/disorders/neurofibromatosis/neurofibromatosis.htm