Introduction: TTC7A gene mutations have recently been identified as a cause of Multiple Intestinal Atresia with Combined Immunodeficiency (MIA-CID), an extremely rare condition with few patients surviving beyond infancy. This case series reports the clinical characteristics of six surviving children.

Methods: Records of all children with MIA-CID and TTC7A mutations confirmed on genetic testing at two tertiary intestinal rehabilitation centres were reviewed retrospectively to identify common phenotypic findings and current management strategies.

Results: Six patients (three female) were identified. All patients had multiple intestinal atresias requiring early surgical intervention. All patients required additional operations for acquired strictures. Mean length of remaining small bowel in continuity was 8 cm (range 4 to 20 cm). Only one patient was able to tolerate any substantial enteral feed; all patients required lifelong parenteral nutrition, except one, who achieved full enteral autonomy after a multivisceral transplantation at five years of age. Four patients received bone marrow transplants with successful engraftment as treatment of their immunodeficiency, which was characterized primarily by severe T-cell lymphopenia. All patients developed intestinal failure associated liver disease. One child had a multivisceral transplantation, a second is listed and a third is undergoing evaluation for multivisceral transplantation. The other three have stable liver disease on non-soybean-based lipid formulations. There is variable occurrence of pulmonary, dermatological and cardiac disease in our cohort.

Conclusions: Patients with TTC7A deficiency leading to MIA-CID can survive beyond infancy with intensive surgical and multidisciplinary medical management. Patients develop intestinal strictures requiring proximal stomas and are unable to establish enteral autonomy leading to parenteral nutrition dependence. Intestinal failure associated liver disease is seen in all patients. The optimal timing of bone marrow transplantation requires consideration, especially for patients considering multivisceral transplantation and for those who do not have a fully matched donor.