If i have a arnold chiari malformation, what are the chances that my son will have these problems too?

Low: Chiari malformation can be isolated, occur secondary to spina bifida, or be part of many different patterns of birth defects (syndromes). If isolated (no other birth defects, medical issues), then it exhibits multifactorial determination in most cases, deriving from multiple genes and in utero environmental factors. This implies a 2-3% risk for each of your children to have chiari.

Low risk: The chiari malformations are different types of defects of the posterior brain. The type two chiari is called arnold chiari and is associated with spina bifida and many malformations of the brain and spinal cord. If this is what you have, it is a congenital defect that is sporatic. Rare cases may be genetic. A good genetic consultation would be appropriate.