Pediatric intestinal pseudo-obstruction found in 3-year-old male with Rett-related mutation of methyl-CpG binding protein 2.

A 3-year-old male with chronic abdominal distention, constipation, and severe malnutrition is diagnosed with pediatric intestinal pseudo-obstruction (PIPO) after extensive evaluation that excluded mechanical, malabsorptive, metabolic, inflammatory, and infectious causes. Aside from speech delay, he has a normal neurologic exam. Whole exome sequencing reveals a pathogenic methyl-CpG binding protein 2 (MECP2) variant, suggesting atypical Rett syndrome. Management includes promotility agents and a gastrostomy tube with cyclic feedings of peptide-based formula, leading to resolution of symptoms. This case highlights the diagnostic complexity of PIPO and the need to consider genetic etiologies, including MECP2-related disorders, even in patients with mild neurologic findings. Early genetic testing and multidisciplinary care are essential for diagnosis and management in this atypical presentation of Rett syndrome with manifestation of PIPO.