The clinical findings in males with a full mutation may include the following:
- Intellectual disability (IQ may range from 22-65).
- Behavioral differences may include:
- Autism spectrum disorder
- Gaze aversion
- Hand flapping
- Hand biting
- Temper tantrums
- Specific facial appearance and physical findings which may include:
- Large head
- Long face
- Large forehead and chin
- Ears that stick out
- High arched palate or sometimes cleft palate
- Macroorchidism - not apparent until after puberty
- Joint hypermobility
- Cardiac findings include mitral valve prolapse and aortic root dilatation.
- Other findings may include:
- Recurrent otitis media
- High blood pressure
Clinical finding in females who have a full mutation:
- Females may have some of the same physical features as males.
- Mild intellectual disability in up to 50% of females (IQ may range from 74-91).
- Other learning difficulties or subtle cognitive features, such as difficulty with math
- Behavioral differences may include the following:
- Social anxiety
- Selective mutism
- Excessive shyness
- Poor eye contact
- Hyperactivity, and/or impulsive behavior.