What is the likelihood of someone with asperger's syndrome having an autistic child?

Can't be sure: The spectrum of autism disorders includes a great variety of individuals across a wide rage of symptoms. Some of these individuals will have genetic syndromes that can be diagnosed, and genetic counselors may be able to determine the risk of passing on the abnormality. In many cases no cause can be identified. We do know that autism disorders can run in families, and we also see it with no history.

The best way to : assess risk is to have pre-pregnancy genetic counseling, giving a 3-generation maternal & paternal family history & obtaining a Chromosomal Microarray on the parent with Autistic Spectrum Disorder. Paternal & maternal age, maternal Folic Acid levels at the time of conception, having the "flu" while pregnant & premature birth are some of the other things that must be factored in to determine risk.