A molar tooth brainstem with a bat-wing fourth ventricle: Joubert syndrome
AbstractA 28-month-old boy was brought by his parents for evaluation of poor growth. Parents reported that the child started neck-holding and sitting at 14 and 24 months of age respectively. He was also unable to walk. His speech was limited to ‘mama’ and ‘dada’ only. Examination showed generalized hypotonia and strabismus. Mother reported that one of the child’s maternal cousins has had similar symptoms. Magnetic resonance imaging (MRI) of the brain was obtained, which showed a molar tooth configuration of the brainstem, bat-wing appearance of the fourth ventricle, absent inferior cerebellar vermis and horizontally placed cerebral peduncles. These radiographic appearances were consistent with a diagnosis of Joubert syndrome. This disease is a rare inherited ciliopathy characterized by typical malformations of the brainstem. Based on genetic analysis, Joubert syndrome is now recognized as a group of several related genetic disorders, which manifest phenotypically in a similar manner. The most common genetic defect implicated in this disorder is a mutation in the gene ARL13B encoding for adenosine diphosphate ribosylation factor like GTPase 13B. Patients usually present early in life with developmental delay and cerebellar ataxia. Most patients have associated abnormal eye movements (usually jerk nystagmus) and an abnormal pattern of breathing (episodic apnoea and tachypnea). Prognosis of such patients is dependent upon the presence of associated abnormalities. About 50% of children eventually learn to walk independently with an ataxic gait.Keywords: Joubert syndrome; ciliopathy
Romani M, Micalizzi A, Valente EM. Joubert syndrome: congenital cerebellar ataxia with the molar tooth. Lancet Neurol 2013;12(9):894–905.
Cantagrel V, Silhavy JL, Bielas SL, Swistun D, Marsh SE, Bertrand JY, et al. Mutations in the cilia gene ARL13B lead to the classical form of Joubert syndrome. Am J Hum Genet 2008;83(2):170–9.
Saleem SN, Zaki MS. Role of MR imaging in prenatal diagnosis of pregnancies at risk for Joubert syndrome and related cerebellar disorders. AJNR Am J Neuroradiol 2010;31(3):424–9.
Journal of Ayub Medical College, Abbottabad is an OPEN ACCESS JOURNAL which means that all content is FREELY available without charge to all users whether registered with the journal or not. The work published by J Ayub Med Coll Abbottabad is licensed and distributed under the creative commons License CC BY ND Attribution-NoDerivs. Material printed in this journal is OPEN to access, and are FREE for use in academic and research work with proper citation. J Ayub Med Coll Abbottabad accepts only original material for publication with the understanding that except for abstracts, no part of the data has been published or will be submitted for publication elsewhere before appearing in J Ayub Med Coll Abbottabad. The Editorial Board of J Ayub Med Coll Abbottabad makes every effort to ensure the accuracy and authenticity of material printed in J Ayub Med Coll Abbottabad. However, conclusions and statements expressed are views of the authors and do not reflect the opinion/policy of J Ayub Med Coll Abbottabad or the Editorial Board.
USERS are allowed to read, download, copy, distribute, print, search, or link to the full texts of the articles, or use them for any other lawful purpose, without asking prior permission from the publisher or the author. This is in accordance with the BOAI definition of open access.
AUTHORS retain the rights of free downloading/unlimited e-print of full text and sharing/disseminating the article without any restriction, by any means including twitter, scholarly collaboration networks such as ResearchGate, Academia.eu, and social media sites such as Twitter, LinkedIn, Google Scholar and any other professional or academic networking site.