Infantile neuroaxonal dystrophy: What's most important for the diagnosis?

• Published in: European journal of paediatric neurology Vol. 12; no. 6; pp. 491 - 500
• Main Authors: Carrilho, Inês, Santos, Manuela, Guimarães, António, Teixeira, João, Chorão, Rui, Martins, Márcia, Dias, Cristina, Gregory, Allison, Westaway, Shawn, Nguyen, Thuy, Hayflick, Susan, Barbot, Clara
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.11.2008
• Subjects: Adolescent; Adult; Atrophy; Brain - pathology; Cerebellar atrophy; Cerebellar Cortex - pathology; Cerebellum - pathology; DNA - genetics; DNA Mutational Analysis; EEG fast rhythms; Electroencephalography; Electromyography; Female; Group VI Phospholipases A2 - genetics; Humans; Infantile neuroaxonal dystrophy; Magnetic Resonance Imaging; Male; Neuroaxonal Dystrophies - diagnosis; Neuroaxonal Dystrophies - genetics; Neuroaxonal Dystrophies - physiopathology; Neurology; Pediatrics; PLA2G6 gene; Tomography, X-Ray Computed; Young Adult; Cerebellar atrophy; EEG fast rhythms; PLA2G6 gene; Infantile neuroaxonal dystrophy
• ISSN: 1090-3798; 1532-2130
• DOI: 10.1016/j.ejpn.2008.01.005

Abstract Background and aims Infantile neuroaxonal dystrophy is a rare neurodegenerative disorder, with onset in the first 2 years of life. Mutations in the PLA2G6 gene were identified in patients with infantile neuroaxonal dystrophy. Our purpose was to review clinical, neurophysiologic, neuroradiologic and neuropathological features of our patients in order to identify the earliest signs of disease. We also correlate these data with the genotype in the mutation positive patients. Methods We reviewed the clinical reports, neurophysiologic and neuropathological studies and brain imaging of our patients. In five patients molecular analysis of the PLA2G6 gene was performed. Results We report 10 patients with infantile neuroaxonal dystrophy. Earliest symptoms presented between 6 and 18 months of age. The first manifestations were arrest in the acquisition of milestones or regression. The first neurological signs were generalized hypotonia and pyramidal signs. Fast rhythms on EEG were observed in all patients. Brain imaging studies showed cerebellar atrophy in all patients, with signal hyperintensity in the cerebellar cortex on T2-weighted images in five. All cases had characteristic axonal spheroids on skin biopsy. Mutations in the PLA2G6 gene were identified in the five patients studied. Three of them had the same homozygous mutations 2370T> G, Y790X. Conclusions Though mutations were detected in the patients studied, a clear genotype–phenotype correlation could not be ascertained. In the appropriate clinical context, characteristic brain imaging and fast rhythms on EEG can support the decision to perform molecular analysis and avoid skin biopsy to confirm diagnosis.