Potential Role of IFIH1 Gene Variant in Autoimmune Hemolytic Anemia: A Case Report

Autoimmune hemolytic anemia is a rare immune-mediated disorder characterized by the destruction of red blood cells. Although the IFIH1 gene, which encodes melanoma differentiation-associated protein 5, has been implicated in various autoimmune and immunologic conditions, its involvement in AIHA has not been reported. We describe a 6-year-old boy with AIHA who carries a heterozygous IFIH1 c.2807+1G>A (rs35732034) variant. The patient showed a favorable response to corticosteroid therapy, maintaining remission on low-dose treatment. Functional studies demonstrate that this variant disrupts splice donor sites, resulting in marked impairment of MDA5 activity. This case suggests a possible genetic contribution of the IFIH1 variant to AIHA and highlights the importance of further investigation into its clinical relevance. Our findings expand current knowledge on IFIH1's role in immune regulation and its contribution to autoimmune pathogenesis.