[Long-term outcome of gliomas of the visual pathway in type 1 neurofibromatosis]. / Langzeitverlauf von Gliomen der Sehbahn bei Neurofibromatose Typ 1.

BACKGROUND: Optic gliomas are frequently associated with neurofibromatosis type 1 (NF1) and belong to the diagnostic criteria of NF1. Different growth rates require differentiated strategies for screening and observation. PATIENTS AND METHODS: 29 patients (25 children < 11 years, 4 adults > 18 years) with visual pathway tumors and NF1 were examined neurologically, ophthalmogically, by means of MRI and VEP. Results were set into context with preceding investigations (mean follow up time 6.5 years). RESULTS: 11 children showed a stable condition, 14 an unfavorable process with substantial loss of vision. Children with an unfavorable process showed a lower age at diagnosis (3.2 versus 5.8 years; p < 0.05), more frequently strabism (11/14 versus 1/11; p < 0.05), optic atrophy (12/14 versus 1/11; p < 0.05), pathological VEP (9/9 versus 2/10; p = 0.001), visual field defects (9/9 versus 1/9) and involvement of the optic chiasm (11/14 versus 3/11; p < 0.05) than children with a stable condition. 3 of 4 adults had no visual symptoms despite involvement of the optic chiasm. CONCLUSIONS: The crucial prognostic factor is the patient's age at the time of diagnosis. Optic gliomas which become symptomatic in early childhood (< 6 years) grow rapidly and require frequent ophthalmologic investigations and MRI. Tumors diagnosed in late childhood (> 6 years) do not progress, allowing for gradual extension of intervals between ophthalmological investigations.

[Fluorescein angiography of retinal changes in patients with neurofibromatosis 2]. / Fluoreszenzangiographie retinaler Veränderungen bei Patienten mit Neurofibromatose Typ 2.

BACKGROUND: Neurofibromatosis 2 (NF2) is a rare autosomal dominant disorder (prevalence 1:37.000) associated with changes in tumor suppressor genes. Intraocular manifestations have been reported as subcapsular cataract, retinal hamartomas, epiretinal membranes, keratopathy in facial palsy, and tumors of the nerves I-V are typical ocular manifestations of NF2. PATIENTS AND MATERIALS: We prospectively examined 7 patients who met the diagnostic criteria of NF2 with regard to retinal changes using fluorescence angiography and red-free fundus photography. RESULTS: In four patients, we found window defects of the pigment epithelium in the macular or paramacular areas. In one patient we observed a combined pigment epithelial and astrocytic hamartoma. A choked papilla was found in two patients. CONCLUSIONS: Presumably, retinal changes in NF2 occur more frequently than has been assumed previously. Our results confirm that in NF2 patients more attention should be paid to abnormalities of the optic disk, the retina and the choroid.

Phenotypic variability associated with 14 splice-site mutations in the NF2 gene.

Neurofibromatosis type 2 (NF2) is an autosomal dominant disorder caused by mutations in the NF2 gene. Patients carrying NF2 mutations are predisposed to cerebral and spinal tumors with bilateral vestibular schwannomas as the hallmark. Using single strand conformation polymorphism and temperature gradient gel electrophoresis analysis, we have screened 87 unrelated NF2 patients for mutations in the NF2 gene. In this study, we report phenotypes associated with 14 splice-site mutations carried by 14 propositi and 11 relatives. The mutations were distributed in exons 2, 3, 5, 7, 8, 14, and 15. These splice-site mutations were associated with various phenotypes, from severe to asymptomatic. Phenotypic variation was also observed within families. Mutations downstream from exon 8 resulted more often in mild phenotypes. No meningiomas were found in any of 13 affected or mutation bearing individuals from three families with splice-site mutations of exons 14 and 15. These data suggest that splice-site alteration is a relatively common cause of NF2, and that unlike other mutations the clinical outcomes of splice-site mutations in the NF2 gene are variable. These results add to the growing body of information on genotype-phenotype correlation in NF2.

Identification of NF2 germ-line mutations and comparison with neurofibromatosis 2 phenotypes.

Neurofibromatosis 2 (NF2) is an autosomal inherited disorder that predisposes carriers to nervous system tumors. To examine genotype-phenotype correlations in NF2, we performed mutation analyses and gadolinium-enhanced magnetic resonance imaging of the head and full spine in 59 unrelated NF2 patients. In patients with vestibular schwannomas (VSs) or identified NF2 mutations, the mild phenotype was defined as < 2 other intracranial tumors and < or = 4 spinal tumors, and the severe phenotype as either > or = 2 other intracranial tumors of > 4 spinal tumors. Nineteen mutations were found in 20 (34%) of the patients and were distributed in 12 of the 17 exons of the NF2 gene, including intron-exon boundaries. Seven mutations were frameshift, six were nonsense, four were splice site, two were missense, and one was a 3-bp in frame deletion. The nonsense mutations included one codon 57 and two codon 262 C-->T transition in CpG dinucleotides. The frameshift and nonsense NF2 mutations occurred primarily in patients with severe phenotypes. The two missense mutations occurred in patients with mild phenotypes, and three of the four splice site mutations occurred in families with both mild and severe phenotypes. Truncating NF2 mutations are usually associated with severe phenotypes, but the association of some mutations with mild and severe phenotypes indicates that NF2 expression is influenced by stochastic, epigenetic, or environmental factors.

The neuroimaging and clinical spectrum of neurofibromatosis 2.

Neurofibromatosis 2 (NF2) is an autosomal dominant disease predisposing to multiple tumors of the central and peripheral nervous system. Bilateral vestibular schwannomas are the hallmark of the disease. To define the clinical spectrum of the disease, we performed gadolinium-enhanced magnetic resonance imaging of the brain and spine as well as neurological, dermatological, and ocular examinations in 48 patients with NF2 diagnosed with the National Institutes of Health diagnostic criteria. Patients were ascertained from patient workshops and publications and from referral as a result of vestibular schwannoma surgery. Vestibular schwannomas were found in 46 patients (96%, 43 bilateral and 3 unilateral), spinal tumors were found in 43 (90%), posterior subcapsular cataracts were found in 30 (63%), meningiomas were found in 28 (58%), and trigeminal schwannomas were found in 14 (29%). The presenting symptoms included hearing loss or tinnitus in 15 patients (31%), multiple or nonspecific symptoms in 15 (31%), skin tumors in 12 (25%), and ocular symptoms in 6 (13%). When the complete spine was imaged, spinal tumors were more common in patients with NF2 than has previously been reported. This is a noteworthy finding, because spinal tumors are a major cause of NF2 morbidity and mortality.

[Ophthalmologic spectrum of neurofibromatosis type 2 in childhood]. / Ophthalmologisches Spektrum der Neurofibromatose Typ 2 im Kindesalter.

BACKGROUND: Neurofibromatosis type 2 (NF2) is a disorder with autosomal dominant inheritance which leads to tumor growth in the central and peripheral nervous system. In affected adult patients there is a typical association with ocular abnormalities like juvenile cataract. METHODS: Ophthalmologic investigation was carried out in ten children aged one to fourteen years with suspected NF2. The diagnosis was confirmed by further clinical examination and-in one patient-by segregation analysis. RESULTS: Nine of these ten children showed ocular abnormalities such as juvenile subcapsular cataracts, retinal hamartomas, optic nerve sheath tumors, fibrotic maculopathies as well as one case of a perineural calcification of the optic nerve and one case of a cerebral hamartoma on the ground of the third ventricle. DISCUSSION: In six children ophthalmological symptoms were the presenting symptom of the disease. The knowledge of these symptoms allows for the diagnosis of NF2 in children who present with isolated ocular deficits or with other typical criteria of the disease. The early diagnosis of the disease may lead to an improved prognosis with regard to preservation of hearing by surgery of bilateral vestibular schwannoma which occur in more than 90% of the NF2-patients.

[Type 2 neurofibromatosis without acoustic neuroma]. / Neurofibromatose Typ 2 ohne Akustikusneurinome.

Bilateral vestibular schwannomas (VSs) are the hallmark of neurofibromatosis type 2 and the crucial criteria for the diagnosis of this autosomal dominant disorder according to the criteria of the National Institutes of Health Consensus Statement. We describe three patients without VSs aged 47, 52 and 69 years, in whom a NF2 gene carrier status was diagnosed by spinal tumors, a cataract and schwannoma of cranial and peripheral nerves. In one case the diagnosis was ascertained by mutation analysis, which revealed a 163bp deletion in the NF2 cDNA, and by the fact that two daughters had the same deletion and NF2 according to the NIH criteria. Our finding suggests that patients with spinal tumors, multiple brain tumors, associated neurinomas or cataract might be carriers of a mutated NF2-gene. The study suggests that the NIH criteria are too restrictive, since NF2 seems to show up for a broader spectrum of phenotypes.

[Ophthalmologic differentiation of various forms of neurofibromatosis]. / Ophthalmologische Differenzierung von Neurofibromatoseformen.

Neurofibromatosis (NF) is one of the most frequent autosomal-dominant hereditary disorders. The molecular-genetic differentiation of NF 1 and NF 2 has important implications for the ophthalmologist. Among 80 patients with NF 1, Lisch nodules were diagnosed in 83% as typical criteria for the disease. In 6 patients who did not meet the NIH criteria for NF 1 and NF 2, the ophthalmological investigation showed no cataracts or Lisch nodules; thus, the ophthalmological examination can help to confirm a subtype of NF. In 8 out of 22 NF 2 patients a juvenile posterior subcapsular cataract was diagnosed. Our examination demonstrates that the diagnostic value of lens opacities in NF 2 patients--especially for early detection of the disease--must be clarified, especially with regard to the fact that there were no patients with incipient cataract and no neuroradiological criteria for the disease.