SOST and aneurysm: The cause of this tamponade and death in some Sost-Crh1+/−120 mice remains unexplained; this is confounded by a lack of any abnormal preceding changes evident in their living equivalents; no predisposing lesions, such as aneurysm, focal thinning, or disruption of the myocardium or coronary vessels were observed histologically in the unaffected animals.