Marfan syndrome is most often expressed by its most visibly associated signs being found with the skeletal system. Often, but not always individuals with Marfan syndrome can grow to above-average height. Also, some have long, slender limbs (dolichostenomelia) with long fingers and toes (arachnodactyly). Others can have arms that are disproportionately long, with thin, weak wrists. Additionally, height and limb proportions can be affected. Marfan Syndrome can also produce other skeletal abnormalities such as a long, narrow face, and crowded teeth because the roof of the mouth is arched.
Those affected by the disorder can also experience an abnormal curvature of the spine (scoliosis), an abnormalidentation (pectus excavatum, which can occur in an asymmetrical fashion), or protrusion (pectus carinatrum) of the sternum are not uncommon. In other words, a person with the disorder can have a breastbone that sticks out or caves in.
Still, other signs can include abnormal joint flexibility, stooped shoulders, malocclusions, a high palate, flat feet, hammer toes, and unexplained stretch marks on the skin.
Marfan syndrome can also cause pain in the joints, bones, and muscles in some people with the disorder. Others can have speech disorders, resulting from symptomatic high palates and small jaws. Also, early osteoarthritis may develop. Additional signs can include limited range of motion in the hips due to the femoral head protruding into abnormally deep hip sockets (protrusion acetabuli).
It is advised that a person with Marfan syndrome be examined each year, regarding the spine and breastbone.
In certain cases a person may have to wear a back brace. In more serious cases, surgery may be required.