The following physical limitations may occur:
Most individuals with Chung-Jansen syndrome are overweight or obese. It is currently not clear why this happens. There might be a relation between the PHIP protein and the leptin-melanocortin pathway which is important for satiety and energy balance. Additionally, it could also be caused by side effects of medication use.
Low muscle tone (hypotonia)
In infancy, it quickly becomes clear that certain milestones are achieved later than the average child. For example, not being able to lift the neck properly in the prone position, having difficulty rolling over, sitting, crawling, standing and walking. Once the child is able to walk, the gross motor skills will remain a challenge as children often have a stiff walking pattern and fatigue easily. Typically, major milestones like cycling and swimming will be achieved later.
There is often an abnormality of the eyes. This includes strabismus, poor vision and cataract. Children often wear glasses and because of a lazy eye, an eye patch can be advised.