Joubert syndrome with bilateral peroneal neuropathies: A case report

Abstract

Abstract Background Joubert syndrome is a rare genetic disorder that presents with various neurological symptoms, primarily involving central nervous system dysfunction. Considering the etiology of Joubert syndrome, peripheral nervous system abnormalities cannot be excluded; however, cases of Joubert syndrome accompanied by peripheral nervous system abnormalities have not yet been reported. Distinct radiological findings on brain magnetic resonance imaging were considered essential for the diagnosis of Joubert syndrome. However, recently, cases of Joubert syndrome with normal or nearly normal brain morphology have been reported. To date, there is no consensus on the most appropriate diagnostic method for Joubert syndrome when imaging-based diagnostic approach is challenging. This report describes the case of an adult patient who exhibited bilateral peroneal neuropathies and was finally diagnosed with Joubert syndrome through genetic testing. Case presentation: A 27-year-old man visited our outpatient clinic due to a gait disturbance that started at a very young age. The patient exhibited difficulty maintaining balance, especially when walking slowly. Oculomotor apraxia was observed on ophthalmic evaluation. During diagnostic workups, including brain imaging and direct DNA sequencing, no conclusive findings were detected. Only nerve conduction studies revealed profound bilateral peroneal neuropathies. We performed whole genome sequencing to obtain a proper diagnosis and identify the gene mutation responsible for Joubert syndrome. Conclusions This case represents the first instance of peripheral nerve dysfunction in Joubert syndrome. Further research is needed to explore the association between Joubert syndrome and peripheral nervous system abnormalities. Detailed genetic testing may serve as a valuable tool for diagnosing Joubert syndrome when no prominent abnormalities are detected in brain imaging studies.