Severe gastrointestinal symptoms caused by a novel DDX3X variant.

Mutations in DDX3X have recently been identified as a common cause of intellectual disability and congenital anomalies. DDX3X (Xp11.4) encodes the DEAD box RNA helicase that plays an important role in gene regulation, apoptosis, and oncogenesis. Here, we report a case of 6-year-old Japanese girl with a novel variant (NM_001193416.3: c.1574A > G; p.(Tyr525Cys), who exhibited psychomotor retardation, severe constipation, and a recurrent paralytic ileus. This is the second report of severe gastrointestinal symptoms being associated with this disease. This report expands the phenotype caused by DDX3X variants and reveals an important clinical aspect for patients and medical staff.