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[Neurofibromatosis type 2 as a result of a de novo mutation: a case report].

INTRODUCTION
Neurofibromatosis type 2 is a dominant autosomic hereditary disease which courses with distinct tumours of the central nervous system and scant cutaneous manifestations. The increased knowledge of the natural history and the genetics of NF 2 acquired over the past few years has shown that clinical onset possibly occurs during the paediatric age and an early diagnosis of these patients can be decisive in the final outcome.


CLINICAL CASE
A 12 year old girl who visited the clinic because of a month old presentation of cervical tumour, otalgia and dysphonia. Exploration revealed signs of cranial nerve disorder and the magnetic resonance (MR) showed bilateral schwannomas of the eighth cranial nerves. The extension study showed ocular, auditory, troncoencephalic and cervical spinal cord disorders. The patient died three months after hospital admission. The genetic study showed a de novo mutation in the NF 2 gene (chromosome 22q12).


DISCUSSION
The identification of the various mutations that cause NF 2 has enabled the early diagnosis of the patient s relatives. However, there are still patients who have not been confirmed genetically. Furthermore, de novo mutations are not predictable. NF 2 diagnosis is still clinical. In the last few years, two disease phenotypes have been defined: mild and moderate/serious, which is associated with an early onset and de novo mutations. The high incidence rate of cataracts and other associated tumours, such as those affecting paraspinal and cutaneous areas together with meningiomas, which up until now could have gone unnoticed, has also been observed. Clinical onset in the paediatric age is more frequent than was expected and shows distinct and subtle symptoms.