Once one individual in a family has been identified as having a gene change causing NF1, other members of the family can have targeted genetic testing to look for the presence or absence of that gene change. Children of an individual with NF1 have a 1 in 2 (50% chance) of inheriting the NF1 gene change from their affected parent. A parent of an individual known to have NF1 may also have an NF1 gene change and be affected with the condition, or the gene change may have occurred for the first time in the affected individual (known as de novo). Approximately 50% of individuals with NF1 have an affected parent, and approximately 50% have a de novo gene change and neither parent is affected. Once an individual has been diagnosed with NF1, It is recommended that their relatives be informed of their risk and seek medical evaluation as appropriate.
Hypothetical example: "John" has NF1 and his specific disease causing NF1 gene mutation has been identified by genetic testing. His brother "Tom" then has testing for the specific NF1 mutation that "John" has, and "Tom’s" test is negative (normal). This negative result in Tom can be used to provide the family information that Tom does not have the NF1 gene change causing John’s NF1. Tom’s children do not then need to receive genetic testing for John’s NF1 mutation. Tom could not have passed down the NF1 mutation, because he did not inherit it himself. You cannot pass on a gene mutation you do not have.
Families with questions about the genetics of NF1 may benefit from genetic counseling. The National Society of Genetic Counselors "Find a Genetic Counselor" searchable directory can be used to locate genetic counselors throughout the United States and Canada.
Other Questions About Neurofibromatosis, type 1
- Who else in my family should I test for Neurofibromatosis Type 1?
- Where do I find other people with Neurofibromatosis Type 1?
- What specialist doctors should I see with Neurofibromatosis Type 1?
- What lifestyle changes should be made for people with Neurofibromatosis Type 1?
- What is the likelihood that someone has Neurofibromatosis Type 1?
