Is there a defective gene in neurofibromatosis?

Mostly genetic. Neurofibromatosis is a mostly inherited problem or mutation with degrees involvement from mild to severe. NF t autosomal dominant pattern of inheritance. People are born with one mutated copy of the NF1 gene in each cell. In about half of cases, the altered gene is inherited from an affected parent. Remaining cases result from new mutations in the NF1 gene,
Several. Genetic testing is commercially available on order by your physician.
Yes. Speak to your doctor about a referral to a geneticist. Many academic centers have NF clinics.