Signs and symptoms can vary greatly among girls and women with triple X syndrome. Many experience no noticeable effects or have only mild symptoms. Being taller than average height is the most typical physical feature. Most females with triple X syndrome experience normal sexual development and have the ability to become pregnant. Some girls and women with triple X syndrome have intelligence in the normal range, but possibly slightly lower when compared with siblings. Others may have intellectual disabilities and sometimes may have behavioral problems. Occasionally, significant symptoms may occur, which vary among individuals. These signs and symptoms may show up as: 
Delayed development of speech and language skills, as well as motor skills, such as sitting up and walking
Learning disabilities, such as difficulty with reading, understanding or math
Behavioral problems, such as attention-deficit/hyperactivity disorder (ADHD) or symptoms of autism spectrum disorder
Psychological problems, such as anxiety and depression
Problems with fine and gross motor skills, memory, judgment and information processing
 Sometimes females with triple X syndrome have these signs and symptoms: 
Vertical folds of skin that cover the inner corners of the eyes (epicanthal folds)
Widely spaced eyes
Curved pinky fingers
Flat feet
Breastbone with an inward bowed shape
Weak muscle tone (hypotonia)
Seizures
Problems with the kidneys
Ovaries that don't work properly at a young age (premature ovarian failure)
