Refractory cyclic vomiting syndrome in TUBB3 R262H syndrome: a case report

TUBB3 R262H syndrome is a rare genetic syndrome caused by a mutation in the β-tubulin isotype III (TUBB3) gene, which is primarily responsible for neurodevelopment. It is characterized by facial dysmorphism, vocal cord paralysis, cyclic vomiting syndrome (CVS), congenital fibrosis of the extraocular muscles (CFEOM), developmental delay, and intellectual disability. To date, the exact prevalence of the syndrome remains unknown, and confirmed TUBB3 R262H syndrome cases are reported infrequently, with limited clinical guidance available on management. In this article, we present the case of a 5-year-old girl, born to first-degree consanguineous parents and a strong family history of intellectual disability. She was delivered at term with difficulty breathing, requiring NICU admission and tracheostomy at 20 days of age. Early complications included feeding difficulties necessitating fundoplication and PEG insertion. Physical examination of the infant revealed 3rd nerve palsy with limited eye movements, ptosis, joint contractures with spasticity in all limbs as well as global developmental delay. Genetic testing confirmed the diagnosis of TUBB3 R262H syndrome, and her clinical course was further complicated by CVS; within a timespan of one year, the patient required a total of 11 admissions due to dehydration and electrolyte imbalances. Her symptoms were resistant to conventional prophylactic management previously described in the literature. This case highlights the complexity of managing cyclic vomiting syndrome in the context of TUBB3 R262H syndrome, particularly when resistant to conventional therapies. It underscores the importance of a holistic and multidisciplinary approach to address the underlying challenges of this rare condition and improve outcomes for affected children and their families. Additionally, it highlights the need for further research to explore the association between TUBB3 R262H syndrome and the severity of CVS, and the importance of exploring alternative management strategies for refractory cases.