MGI:1098791Mice homozygous for a missense mutation exhibit perinatal lethality, low birth weight, cyanosis, cardio-respiratory failure, and absent milk spots. Mice homozygous for a knock-out allele show embryonic growth retardation, small egg cylinders, disorganized extraembryonic tissue, failure of primitive streak formation and gastrulation, and complete embryonic lethality by E9.5.