GPI and congenital nonspherocytic hemolytic anemia: Glucose-6-phosphate isomerase (GPI) deficiency (MIM 613470), one of hereditary nonspherocytic hemolytic anemias (HNSHA), is a rare autosomal recessive hereditary disease caused by homozygous or compound heterozygous mutations of GPI gene on chromosome 19q13 [1].