To report an extremely rare case of Coach syndrome presenting with the classical pentad of cerebellar vermis hypoplasia, oligophrenia, ataxia, ocular abnormalities, and hepatic fibrosis in a young adult with familial chronic liver disease.

COACH syndrome is an extremely rare ciliopathy which is characterized by multisystem involvement including congenital hepatic fibrosis and cerebellar vermian hypoplasia, often leading to delay in diagnosis due to primary gastroenterological presentation. Early recognition is important for genetic counseling, particularly in families with a history of unexplained liver disease and neurological symptoms.

An 18-year-old male from Western India with prior history of poor scholastic performance presented with a three-year history of recurrent haematemesis. He had a significant family history of chronic liver disease, with decompensation leading to death in his elder brother at 20 years of age. Patient initially presented with decompensated chronic liver disease in the form of oesophageal varices along with neurological symptoms in the form of cerebellar ataxia. Examination showed ophthalmoplegia, chorioretinitis with optic disc pallor, fronto-temporal predominant cognitive impairment, UMN quadriparesis and positive cerebellar signs. Neuroimaging revealed the pathognomonic molar tooth sign and liver biopsy showed hepatic fibrosis with PAS-positive intracytoplasmic material. In view of the combined presentation, along with significant family history and cerebellar vermis hypoplasia, oligophrenia, ataxia, eye abnormalities and hepatic fibrosis, the possibility of COACH syndrome, a subtype of Joubert syndrome was considered and whole exome sequencing was done which confirmed the same.

This case underlines the significance of a holistic approach to diagnosing multisystemic conditions for management and genetic counselling. Clinical history, examination, combined with neuroimaging and histopathology followed by genetic confirmation paved the way to diagnosing COACH syndrome and helped in timely genetic counselling.