Autoinflammation with infantile enterocolitis associated with a novel CARD domain mutation in NLRC4: a case report and literature review.

BACKGROUND

Autoinflammation with Infantile Enterocolitis (AIFEC, OMIM#616050) is a rare autosomal dominant autoinflammatory disorder caused by gain-of-function mutations in the NLRC4 gene. The disease is characterized by recurrent systemic inflammatory flares with enterocolitis as a hallmark feature, though clinical presentations are broad and often nonspecific.

CASE PRESENTATION: This report describes a noteworthy case of a pediatric patient with rare NLRC4 gene mutation leading to AIFEC. The patient was a 2-year-and-4-month-old female who presented with recurrent fever, chronic diarrhea, mucous bloody stools, and multi-system involvement. She had a history of multiple infections since early childhood. Laboratory investigations indicated significantly elevated inflammatory markers and endoscopic examination revealed multiple ulcers in the ileocolonic region. Whole-exome sequencing identified a de novo heterozygous mutation c.167A > G (p.His56Arg) in the CARD domain of NLRC4 gene, which was validated by Sanger sequencing and functionally assessed for pathogenicity. This specific gene locus mutation has not been reported in domestic or international literature to date. Clinical remission was achieved following infliximab treatment.

CONCLUSION

This case identifies a novel NLRC4 variant (c.167A > G, p.His56Arg) located in the CARD domain. Our findings expand the known mutational and phenotypic spectrum of AIFEC and add to emerging clinical evidence suggesting the potential utility of infliximab as a targeted therapeutic option for this rare autoinflammatory condition.