Clinical and Mutation Description of the First Iranian Cohort of Infantile Inflammatory Bowel Disease: The Iranian Primary Immunodeficiency Registry (IPIDR).

We describe a cohort of 25 Iranian patients with infantile inflammatory bowel disease (IBD), 14 (56%) of whom had monogenic defects. After proper screening, patients were referred for whole exome sequencing (WES). Four patients had missense mutations in the , and one had a large deletion in the . Four patients had mutations in genes implicated in host:microbiome homeostasis, including deficiency, and two patients with novel mutations in the and . We found a novel homozygous mutation in the in a deceased patient and the heterozygous variant in his sibling with a milder phenotype. Three patients had combined immunodeficiency: one with ZAP-70 deficiency (TBNK), and two with atypical SCID due to mutations in and . One patient had a mutation without neutropenia. Eleven of the 14 patients with monogenic defects were results of consanguinity and only 4 of them were alive to this date.