Sideroblastic anemia with B-cell immunodeficiency, periodic fevers, and developmental delay (SIFD), a rare multisystemic syndrome, occurs due to loss-of-function mutations in the tRNA nucleotidyl transferase 1 (TRNT1) gene. This evidence concerns the gene TRNT1 and congenital sideroblastic anemia-B-cell immunodeficiency-periodic fever-developmental delay syndrome.