Further analysis revealed that previously reported biallelic mutations in the PGM3 gene were associated with severe immunodeficiency and glycosylation disturbance, while monoallelic mutations were associated with mild phenotypes like IFE, suggesting a quantitative correlation between genetic impairment and phenotypic severity, which help explain the mild symptoms and incomplete penetrance in individuals with IFE. This evidence concerns the gene PGM3 and Immunodeficiency.