Abstract: The present invention relates to a composition comprised of AKAP12 (A-Kinase anchoring protein 12) and to uses of AKAP12 mutant zebrafish as an animal model. More particularly, the following characteristics are noted in the present AKAP12 mRNA knockdown zebrafish: crooked or shortened tail, inability to move normally, non-uniform micro-vasculature in the brain, and change in heart shape with non-uniform and weak heartbeats. It also has various circulatory and genetic defects, such as hemorrhage from the ventricles of the heart, brain, and retina. All of these defects can be cured with AKAP12 injection. Therefore, AKAP12 can be used as an active component for a composition to prevent and heal circulatory and genetic defects that are caused by AKAP12 deficiency, and as a hemorrhage inhibitor. Further, the AKAP12 deficient mutant zebrafish can be useful as an animal model for verification of effectiveness of treatment for genetic defects in the circulatory system.