A Classical Sign with Uncommon Symptoms: Section Joubert Syndrome Presenting with Retinal Dystrophy and Keratoconus

Abstract

Joubert Syndrome and Related Disorders (JSRD) are a rare group of autosomal recessive ciliopathies characterised by the pathognomonic molar-tooth sign on Magnetic Resonance Imaging (MRI) of the brain. The clinical manifestations are usually multisystemic and may involve multiple organs. Early diagnosis is warranted, as neurological, renal, and ocular symptoms may remain latent that require multidisciplinary management. A 20-year-old male born to third-degree consanguineous parents, with a known history of global developmental delay and stage V chronic kidney disease on regular maintenance haemodialysis, presented with acute-onset high-grade fever and cough, along with a recent history of severe lower respiratory tract infection requiring mechanical ventilation. On examination, cerebellar signs including broad-based gait, dysmetria, dysdiadochokinesia, and intention tremors were noted, along with bilateral retinal dystrophy and keratoconus of the left eye. Laboratory investigations revealed anaemia and deranged renal function tests. MRI of the brain demonstrated the characteristic molar-tooth sign, with elongated superior cerebellar peduncles, agenesis of the cerebellar vermis, and a characteristic bat-wing appearance of the fourth ventricle. Ultrasonography of the kidneys showed bilaterally atrophied kidneys. A diagnosis of Joubert Syndrome with oculorenal involvement was made based on the neurological, renal, and ocular manifestations. This case highlights the typical clinical and neuroimaging features of JSRD, along with the additional finding of keratoconus, an uncommon ocular manifestation. Early diagnosis is essential for appropriate prognostication, genetic counselling, and timely intervention of organ-specific screening and surveillance, particularly in consanguineous families since the pattern of inheritance is recessive.