There are some of the physical features common to many, but not all, people with Fragile X syndrome. Even if present, the degree of visible effect varies from person to person. The features are more common in males than in females and are seen in approximately 50% of individuals

• The ears may be prominent.
• There may be a high forehead and/or long jaw, making the face look long, although this is often not apparent until puberty.
• Eye & vision impairments may cause a squint or turn in the eye which may only be apparent when the eye is stressed, for example in strong sunlight.
• Eyelids can tend to puffiness
• The chest may a “hollow” look
• There may be a single palmar crease Wikipedia description
• Flat feet (pes planus) may be evident
• A high arched mouth palate may be present
• Low muscle tone and hyper-extensible joints can cause awkwardness of movement and a “double jointed” look
• Large testicles (may be evident after puberty)
• The skin can be especially smooth and soft.
• Growth patterns indicate that children with Fragile X, especially males, are of average height or tall while young, but tend to be average once they are adults.

These features are more common in males than in females and are seen in approximately 50% of individuals.