Ocular alterations in a rare case of segmental neurofibromatosis type 1 with a non-classified mutational variant of the NF-1 gene

BACKGROUND: Neurofibromatosis type 1 (NF-1) is an autsomal dominant disorder which can occasionally result from somatic mosaicism and manifest as segmental forms of the disease. METHODS: A 37-year-old woman with ascertained NF-1, based on clinical diagnostic criteria and genetic analysis, was referred for ophthalmological evaluation. Genetic analysis, magnetic resonance imaging (MRI), complete ophthalmological examination, and near infrared reflectance (NIR) images at 815 nm of the retina were obtained. RESULTS: Genetic analysis revealed a non-classified mutational variant of the NF-1 gene identified as NM_000267.3:c2084T > C (p.Leu695Pro.T). MRI demonstrated non-symptomatic bilateral optic nerve gliomas. The only cutaneous sign was a subcutaneous neurofibroma of the posterior cervical region. Slit-lamp examination showed bilateral Lisch nodules. NIR images of the retina did not show any choroidal hamartomas. DISCUSSION: We report a rare case of segmental neurofibromatosis with a non-classified mutational variant of the NF-1 gene described in only one previous case in the literature. The patient presented with clinical features of NF-1 localized to the head and neck region, compatible with diagnosis of segmental NF-1. Interestingly, ocular manifestations included bilateral optic nerve gliomas and Lisch nodules, but no choroidal hamartomas. KEYWORDS: Lisch nodules; mosaicism; neurofibromatosis type 1 gene; segmental neurofibromatosis