Helping my sons pediatrician help me. Son diagnosed with autism. No blood work to rule out anything else. What tests should he order?

Current standards. For genetic testing in a child with autism include comparative genomic hybridization & dna probe for fragile x. If there are physical findings like unusual facial features or hyper- or hypo-pigmented areas of skin (seen with a wood's light), there may be more specific tests. The need for an MRI of the brain is determined by head growth (birth-present) & specific findings on neurological exam.
Autism work up. The current complete evaluation of a child with autism includes a thourough physical exam (including a wood's lamp exam for hypopigmented lesions of tuberous sclerosis), hearing test, chromosomal microarray, cbc, and ferritin. In cses where there is clinical deterioration, add mecp 2 (to r/o rett's disease).
Other tests. Other tests you might want to ask about include an eeg (brain wave test), chromosome test (karyotype), specific microdeletion tests such as williams syndrome and prader willi syndrome. I agree with the fragile x test. There are many other tests which may or may not be helpful. Many of these tests would fall under the category of alternative medicine or experimental.