Earliest clinical manifestations and natural history of neurofibromatosis type 2 (NF2) in childhood: A study of 24 patients

Background: Neurofibromatosis type 2 (NF2) is an autosomal dominant disease characterised by the development of multiple nervous system tumours, ocular abnormalities, and skin tumours. Although classically considered a disease of adults, initial signs and/or symptoms may be evident in childhood and are often unrecognised. Objectives: The aim of this study was to identify the earliest clinical presentations of NF2 and to characterise the clinical course and outcome in children with NF2. Methods: We have performed a retrospective (years 1990-1998) and prospective (years 1998-2004) study of 24 patients (10 males, 14 females; currently aged 4 to 22 years) fulfilling the revised (Manchester) NF2 criteria seen at the Universities of Catania and Rome, Italy. Results: Causes of referral prior to a definitive diagnosis of NF2 were: 1) Ophthalmologic problems: early onset lens opacities (n=3); strabismus (n=3) and amblyopia (n=3) (due to underlying cranial nerves and/or brain tumours); 2) Otolaryngology problems: hearing loss and tinnitus (n=2) in early teens disregarded or treated as ear infections; hoarse (n=1) or bitonal (n=1) voice; 3) Neurological dysfunction: seizures secondary to intracranial meningioma (n=1) or vestibular schwannomas (VS) (n=1), neurological dysfunction related to brainstem and/or spinal cord tumours (n=7), isolated and multiple cranial nerve deficits (n=10), and peripheral neuropathy secondary to schwannomas (n=4); 4) Skin manifestations: schwannomas mis-diagnosed as neurofibromas because of associated cafe-au-lait spots (n=2); cafe-au-lait spots (n=8) and skin tumours (n=3). A family history was relevant in 20% of the patients. Molecular genetic analysis of the NF2 gene revealed typical truncating mutations in all the 5 familial cases and in 2/10 sporadic cases analysed. Conclusions: Children with NF2 often first come to medical attention because of ocular, subtle skin, or neurological problems the significance of which is realised when they later present with more classical symptoms due to bilateral VS or other intracranial tumours. The clinical course at this young age is highly variable, depending on tumour burden, early surgical intervention, surgical outcome after tumour resection, and complications.