Delayed IPEX Syndrome with a Rare Mutation

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is a rare, life-threatening X-linked recessive disorder caused by FOXP3 gene mutations, with an incidence of less than one in a million.It typically presents in infancy, with half of the cases manifesting within the first month, and is characterised by severe enteropathy, Type I diabetes, and recurrent infections.Here, the authors report a rare case of late-onset IPEX in a five-year boy with acute disease onset, multiple organ involvement, recurrent diarrhoea, diabetes, and infections.Genetic testing identified a novel c. 210 + 1G >C mutation in FOXP3 which was not previously reported.The patient underwent a successful haematopoietic stem cell transplantation (HSCT) and remained relapse-free during a one-year follow-up.This case highlights the potential for late-onset IPEX, the importance of genetic testing in atypical cases, and the efficacy of HSCT as a curative treatment.Further research is needed to explore the long-term outcomes of HSCT and the genotypephenotype correlations in IPEX syndrome.