Rapidly progressing generalised tooth resorption associated with primary immunodeficiency due to XIAP/BIRC4 mutation.

Primary immunodeficiency (PID) with a mutation in the X-linked inhibitor of apoptosis protein (XIAP/BIRC4) is a rare congenital condition characterised by haemophagocytic lymphohistiocytosis (HLH). Dental anomalies for this condition are not well documented in the literature. We report an unusual case of generalised, rapid resorption of all primary teeth in a 7-year-old boy. Affected teeth were extracted to avoid potential pulpal and periapical infection. Combined clinical assessment, plain film radiograph, microcomputed tomography and histopathology enabled the identification of macroscopic and microscopic features associated with the rapid resorption, including gross infiltration of calcific material inside the enlarged pulp space. This case documents the importance of regular clinical and radiographic review in primary immune deficiency XIAP/BIRC4, as well as the need to better understand the pathogenesis of rapid resorption to inform clinical care.