My son aged 4 years is a case of delayed development, delayed speech, hyperactive. What is all this?

Diff. To say. Please get a full evaluation from a well trained child psychiatrist. You both deserve it.
A neurodevelopmental. Disorder, the etiology & functional impact of which a Developmental/Behavioral Pediatrician evaluates by reviewing your prenatal, labor & delivery records, all of his medical, therapeutic & educational records, parent & teacher checklists & family history, then doing physical, neurological & neurodevelopmental exams, a DNA Probe for Fragile X, Chromosomal Microarray & neuroimaging if needed.