Please have yourself and son checked for connective tissue disorders by a geneticist. There are many symptoms like easy bruises, very flexable, early arthritis, poor eyesight, and many others. Symptoms usually run "true" in a family but sometimes children can have a worse case called a mutation. We do use blood pressure medications to control the growth rate.
I am not a pediatric cardiologist, but in adults control of blood pressure and heart rate with medications such as beta blockers can prevent the progression of dilatation of aortic aneurysms.