When two Ank-1(MRI96570/+) G2 progeny were intercrossed, Ank-1(MRI96570/MRI96570) mice were born with severe jaundice and died within several days of birth (Figure 1B), suggesting that homozygosity for the Ank-1(MRI96570) mutation caused lethal anemia. The gene discussed is ANK1; the disease is anemia.