The jaw is often underdeveloped and sloping (receeded). This, along with
small nasal passages can cause breathing problems, especially at night, known
as sleep apnea. In minor cases the person may breath heavily or snore, in
more extreme cases a tracheostomy or other breathing equipment may be
required to help the person breathe.
A small, uneven jaw can also cause eating and chewing problems due
to misaligned and crowded teeth. This can be helped by orthodontics
and surgery.
Someone with TCS should have normal intelligence. It is thought that any
delay in development OF TCS people is probably due to hearing loss.