Stem cell transplantation for tetratricopeptide repeat domain 7A deficiency: long-term follow-up

Mutations in the tetratricopeptide repeat domain 7A (TTC7A)gene cause a severe form of very early-onset inflammatory bowel disease (VEOIBD). TTC7A has a crucial role in chaperoning the enzyme phosphatidylinositol-4-Kinase-3-alpha from the Trans-Golgi apparatus to the plasma membrane to facilitate phosphorylation of phosphatidylinositol (PI). The composition of the plasma membrane in particular levels of phosphorylated PI (PI-4P) are crucial for preserving epithelial cell polarity and survival . The clinical spectrum of the disease varies from multiple intestinal atresias (MIA) to severe autoimmune enterocolitis clinically evident by infantile-onset intestinal obstruction/failure, bleeding and diarrhoea. Furthermore, the disease can be associated with severe immunodeficiency or autoimmune phenomena owing to the central role of TTC7A in thymic architecture. Limited published data on TTC7A deficient patients suggests a median survival