Chronic atrial and intestinal dysrythmia syndrome: A late-onset intestinal pseudo-obstruction and cardiac dysfunction due to an SGO1 mutation.

Objectives: Pediatric intestinal pseudo-obstruction (PIPO) is a rare, heterogeneous, and severe gut motility disorder. In 2014, Chetaille et al. described chronic atrial and intestinal dysrhythmia (CAID) syndrome associated with a recessive SGO1 mutation (p.Lys23Glu) linking it to both intestinal pseudo-obstruction and cardiac dysrhythmia. This study aimed to describe the clinical and nutritional features and outcomes of pediatric patients with the homozygous SGO1 (p.Lys23Glu) mutation. Methods: We retrospectively enrolled children under 18 years with PIPO and homozygous (p.Lys23Glu) SGO1 mutation. Results: Eight patients were included (five girls), two were first-degree relatives. All exhibited a typical PIPO clinical presentation, but with a later onset than usually seen in primary PIPO (median age: 6.3 years). Contrast studies revealed massively distended small bowel and colon in all patients. Antroduodenal and/or colonic manometry, performed in six patients, revealed a neuropathic pattern. A full-thickness intestinal biopsy showed variable fibrosis of the smooth muscle internal layer associated with an abnormal presence of Cajal cells within the muscular layers. All patients required parenteral nutrition (PN) at a median age of 11.8 years. Five patients needed an ileostomy. At 18 years, one patient was off PN. Three patients developed sinus dysfunction: one at the time of PIPO diagnosis and two later. All required pacemakers. One patient died in her twenties secondary to cardiac complications. Conclusions: Recessive SGO1 mutation is a form of late onset PIPO associated with sinus dysfunction. Long-term outcome is unclear. Cardiac, intestinal, and neurologic follow-up is recommended as cerebral small vessel disease has been described in adults.