Is there a genetic test to see if someone has chiari?

No. Children born with open spina bifida are at increased risk for chiari type 2 due to lower position of posterior brain structures. There may be some increased risk for this problem in some families but there is a nutritional role and other factors also. Adults without any spina bifida history can get chiari type 1. There is no firm genetic pattern that is predictive of the chiari type 1.
Chiari. There are different types of chiari disease....Do you mean the liver one or the brain malformation one?