Joubert Syndrome with a Rare Ocular Phenotype: Coloboma with Retrobulbar Cysts - A Case Report.

Joubert syndrome (JS) is a rare, autosomal recessive, genetic syndrome that derives from the defects in a sensory organelle, the primary cilia. It is a multiorgan disorder affecting the brain, kidneys, liver, and eyes. The most common presenting feature in the newborn period is hypotonia, abnormal eye movements, irregular breathing pattern, characterized by episodic hyperpnea and apnea, later on, ataxia, and developmental retardation. Besides, a range of highly variable, systemic and ocular features can be present. We report a case of 2-month-old female infant, the product of a consanguineous marriage, with a sibling affected by JS, presenting with intermittent hyperpnea, apnea, facial dysmorphism, strabismus, oculomotor apraxia, proptosis, retinal dystrophy, chorioretinal coloboma, and large retrobulbar cysts communicating with the coloboma. Magnetic resonance imaging of the brain revealed the characteristic neuroradiologic finding, the "molar tooth sign." The child does not fix or follow the light, and the visual prognosis with all the ocular features of the syndrome present is extremely poor. In addition to adding to the diversity of ocular phenotypes, this case reiterates the importance of identifying the syndrome, understanding the varied ocular phenotypic presentations, need for further research on causative genes, prenatal diagnosis in affected families, interventions, and adequate genetic counseling.