<unk>  affects about 2–3% of the general population. 75–90% of the affected people have mild<unk> . Non-syndromic or<unk> iopathic<unk>  accounts for 30–50% of cases. About a quarter of cases are caused by a genetic disorder. Cases of unknown cause affect about 95 million people . It is more common in males and in low to middle income countries.
Intellectual disability
Autism
Developmental disability
Autism spectrum  disorder  1
Global developmental delay
Language delay
Nonverbal autism
Nonverbal learning disorder