Autism

In autism, three main areas affected by the disorder are speech or communication, social skills, and behavior. Individuals with autism do not necessarily look obviously different from others, but may be impaired in their speech, behavior, learning, and the way they perceive the world around them. It is mostly seen in Boys than girls.
Social Skills: Your child may have problems using social skills to
share a common focus with another person about the same object;
play with others and share toys;
understand feelings;
make and keep friends.
Common Behaviors: A child with autism may
have trouble changing from one activity to the next;
flap hands, rock, spin or stare;
get upset by certain sounds;
like only a few foods;
have limited and unusual interests, for example, talk about only one topic or keep staring at one toy.
Communication Skills: Your child may have trouble with communication skills like understanding, talking with others, reading or writing. Sometimes, she might lose words or other skills that she's used before. Your child may have problems
understanding and using gestures, like pointing, waving, or showing objects to others; following directions; understanding and using words; having conversations; learning to read or write. Or she may read early but without understanding the meaning—called hyperlexia.