Patients with JBTS have variable features which range from mild to severe:
- Facial features of a prominent forehead, broad upturned nose and open mouth are common.
- Infants may also have hypotonia (floppiness), ataxia (unsteady walk) and developmental delay. This can make sitting and standing difficult to achieve in children.
- Jerky eye movements and difficulty moving the eyes to follow an object (oculomotor apraxia).
- Learning difficulties affecting speech and behaviour may also be present.
- Epilepsy.
- Kidney cysts which affect kidney function is associated in 25% of cases.
- Abnormal breathing patterns may also be noticed early on in infancy.