title: Downbeat nystagmus as the presenting symptom of infantile neuroaxonal dystrophy: a case report.
abstract: Infantile neuroaxonal dystrophy is a rare neurodegenerative disorder characterized by infantile onset and rapid progression of psychomotor regression and hypotonia evolving into spasticity and dementia. Although nystagmus is a well-established neurological sign in infantile neuroaxonal dystrophy, it is mainly described as pendular and noticed in later stages of the disease. We report a 13-month-old girl with infantile neuroaxonal dystrophy harboring a compound heterozygous mutation in the PLA2G6 gene with downbeat nystagmus as the only presenting symptom. Our case indicates that downbeat nystagmus can be a rare but very early onset sign of cerebellar involvement in infantile neuroaxonal dystrophy and can anticipate the appearance of psychomotor regression and neuroradiological abnormalities.
authors.affiliation: Pediatric Neurology Unit, Azienda Ospedaliera ASMN, Istituto e Cura a Carattere Scientifico, 42123 Reggio Emilia, Italy. Electronic address: danielefrattini@gmail.com.
authors.forename: Daniele
authors.initials: D
authors.lastname: Frattini
authors.affiliation: Child Neuropsychiatry Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy. Electronic address: nnardocci@istituto-besta.it.
authors.forename: Nardo
authors.initials: N
authors.lastname: Nardocci
authors.affiliation: Neuroradiology Unit, Azienda Ospedaliera ASMN, Istituto e Cura a Carattere Scientifico, 42123 Reggio Emilia, Italy. Electronic address: pascarella.rosario@asmn.re.it.
authors.forename: Rosario
authors.initials: R
authors.lastname: Pascarella
authors.affiliation: Molecular Neurogenetics Unit, Fondazione IRRCS Istituto Neurologico Carlo Besta, Milano, Italy. Electronic address: panteghini.c@istituto-besta.it.
authors.forename: Celeste
authors.initials: C
authors.lastname: Panteghini
authors.affiliation: Molecular Neurogenetics Unit, Fondazione IRRCS Istituto Neurologico Carlo Besta, Milano, Italy. Electronic address: garavaglia@istituto-besta.it.
authors.forename: Barbara
authors.initials: B
authors.lastname: Garavaglia
authors.affiliation: Pediatric Neurology Unit, Azienda Ospedaliera ASMN, Istituto e Cura a Carattere Scientifico, 42123 Reggio Emilia, Italy. Electronic address: fusco.carlo@asmn.re.it.
authors.forename: Carlo
authors.initials: C
authors.lastname: Fusco
mesh_terms: D000293:Adolescent; D001284:Atrophy / Q000473:pathology; D002531:Cerebellum / Q000473:pathology; D005260:Female; D054522:Group VI Phospholipases A2 / Q000235:genetics; D006801:Humans; D008279:Magnetic Resonance Imaging; D009154:Mutation / Q000235:genetics; D019150:Neuroaxonal Dystrophies / Q000503:physiopathology*; D009759:Nystagmus, Pathologic / Q000175:diagnosis* / Q000235:genetics
chemical_list: D054522:Group VI Phospholipases A2; C516475:PLA2G6 protein, human
keywords: Cerebellar atrophy; Downbeat nystagmus; Infantile neuroaxonal dystrophy (INAD); PLA2G6 gene