Neuropathy, ataxia, retinitis pigmentosa: a case of a mother and two siblings

We describe the ophthalmic manifestations of Neuropathy, ataxia, retinitis pigmentosa (NARP) syndrome in three related patients.

We examined a mother and her two children, who were carriers of the mt 8993T>G mutation. The mother, patient I, is the first known carrier within the family pedigree. Patients II and III are her children from a non-carrier father. NARP syndrome and the heteroplasmy levels were established prior to the first referral of the patients to the Ophthalmology department.We performed a visual acuity testing, followed by a biomicroscopic and fundus examination, as well as additional multimodal imaging testing: optical coherence tomography (OCT) and fundus autofluorescence (FAF), and functional testing: electroretinogram and visual field.

All patients had the clinical manifestations of NARP syndrome, which were variably expressed symptomatically, on the fundus exams, electroretinogram, and visual fields.

Once genetically established, NARP syndrome, as other mitochondrial disorders, has a very variable progression with different degrees of severity. A multimodal approach involving both neurological and ophthalmological diagnosis of NARP syndrome is necessary in order to establish the course of the disease and the measures to be taken.