<prompt> Retts syndrome is characterized by all of the following EXCEPTCommon in girlsSevere mental retardationHand wringing presentDecrease head circumference at birth  <response>: D Decrease head circumference at birth Two syndromes with autistic features namely Aspergers syndrome Retts syndrome. Aspergers syndrome is characterized by autism without any significant delay in language or cognitive development including intelligence. This syndrome occurs predominantly in boys male: female ratio 8:1. It probably represents mild cases of autism. Retts syndrome is a disorder which is only reported in girls so far. After an apparently normal early development and normal head circumference at birth, there is a deceleration of head growth between the age of 5 months and 30 months. There is also a loss of purposive hand movements and acquired fine motor manipulative skills between the same ages, with subsequent development of stereotyped hand movements e.g. hand wringing. Later, other movement disorders also develop and severe mental handicap is invariable. 