Importance of Genetic Diagnosis in Global Developmental Delay: A Case of Cabezas Syndrome Caused by CUL4B Gene Deletion and Not Identified by Array-CHG.

Global developmental delay (GDD) and intellectual disability (ID) are common reasons for referral to neurodevelopmental assessment. The etiology of GDD and ID can be genetic, acquired, or multifactorial. We report a case of a 10-year-old boy with ID and GDD who was diagnosed with Cabezas syndrome, a rare genetic disorder caused by a deletion of the CUL4B gene. Despite normal results from previous testing, exome sequencing with copy number variation analysis led to the identification of the deletion. Early diagnosis of GDD and ID is crucial for effective patient management, including planning interventions and providing support, therapy, and genetic counseling for families.