Joubert syndrome associated with pathogenic variants in the TMEM67 gene

Introduction: Joubert syndrome (JS) is an autosomal recessive congenital ciliopathy, which has been associated with a mutation in the TMEM67 gene. JS is characterized by delayed psychomotor development, ocular alterations, as well as renal, skeletal, and hepatic manifestations. Magnetic resonance imaging (MRI) identifies the pathognomonic alteration, which is a malformation in the cerebellum and brainstem, with a characteristic image of the “molar tooth sign” (MTS). Objective: to describe the clinical picture of a pediatric SJ patient in whom variants in the TMEM67 gene were detected. Case report: three-year-old male with delayed psychomotor development, hypotonia, isometropic amblyopia, strabismic amblyopia, and downward vertical nystagmus. In the MRI, the MTS was observed since the superior cerebellar peduncles were found to be elongated. By genetics, through whole exome sequencing, two variants in the heterozygous state of the TMEM67 gene were found. Conclusions: children with delayed psychomotor development and nystagmus should undergo a comprehensive ocular, neuroimaging, and genetic examination to identify the diagnosis of JS. © 2022 American Nuclear Society. All rights reserved.