To investigate the etiology of the patient’s iron deficiency anemia, anti-tissue transglutaminase (tTG) IgA and IgG antibodies were assessed and found to be strongly positive: anti-tTG IgA 215 U/mL (positive: > 10.0 U/mL) and anti-tTG IgG 20 U/mL (positive: > 10.0 U/mL) and the total serum IgA level was within the reference range. Here, TGM2 is linked to Iron deficiency anemia.