We have analyzed cDNA from a 46-year-old atypical neurofibromatosis type 2 (NF2) patient who had lumbar tumors, cataract and schwannomas of peripheral nerves but no vestibular schwannomas, and have identified a 163-bp deletion in the NF2 transcript. The deletion is predicted to remove 54, alter 15 and add four extra amino acids at the C-terminus of the NF2-gene product. The same deletion was found in her two daughters and in a 3-year-old grandson. Bilateral vestibular schwannomas were detected in the two asymptomatic daughters, whereas no abnormality was found in the grandson.