The International Sacral Agenesis/Caudal Regression Association – Informing and connecting the sacral agenesis/caudal regression syndrome community The International Sacral AgenesisCaudal Regression Association Informing and connecting the sacral agenesiscaudal regression syndrome community Sacral Agenesis Caudal Regression Syndrome Sacral agenesis also called caudal regression syndrome SACRS is a rare congenital condition in which the lower part of the spine does not fully develop. The absence of the lower spine and spinal cord potentially also impacts the formation and function of lower parts of the body such as the legs and pelvis and organs such as the kidneys. The way that the condition can impact individuals varies greatly. Regardless of the range of physical characteristics that an individual with this condition might experience you will see on this website that individuals with this condition know no limits and are fully capable of living happy successful and productive lives.