Purpose: To provide presymptomatic diagnosis for children of sporadic neurofibromatosis 2 patients in whom no NF2-mutations were found by screening their blood-DNA.
Methods: Tumors of four patients were analyzed for NF2 allele losses and mutations.
Results: Nonsense NF2 mutations and NF2 allele losses were found in all tumors. None of these alterations was found in any of eight children examined, suggesting that these children did not inherit the disease.
Conclusions: Finding two genetic alterations of a tumor suppressor gene in associated tumors is useful for presymptomatic diagnosis. Identification of the lost allele in tumors alone also enables exclusion of disease transmission in 50% of cases.