Suggest Treatment For Trigonocephaly

My son is 20 months. He has been diagnosed with trigonocephaly in the last week. He is extremely small and has multiple neuromuscular development delays. He does not talk and the doctor is worried that there might be pressure on his brain. we go to see the pediatric neurosurgeon in a few weeks. I'm afraid he may have say-meyers syndrome. can you please let me know what kind of genetic testing needs to be done to see if it is say-meyers syndrome. They are doing genetic testing now and I am waiting to here back.