Imerslund-Grasbeck syndrome is a rare autosomal recessive disease mainly characterized by megaloblastic anemia and proteinuria. Herein, we reported two cases presenting with anemia and growth retardation. Especially, case 1 manifested proteinuria and case 2 was diagnosed with α-thalassemia. The whole gene sequencing confirmed that they harbored the same homozygous mutation in the AMN gene (c.C742T). Both of them showed a good hematological and neurological improvement to intramuscular injection of cobalamin. However, proteinuria still existed for case 1 and was unknown for case 2.