Fragile X syndrome, also known as FXS or Martin-Bell syndrome, is a genetic disease that can affect females but for some reason males are affected more severely.
Those affected with FXS commonly have a delayed speech development until age two. Most Males affected usually have mild to moderate intellectual disability, while about one third of affected females are intellectually disabled.
Children affected by FXS will maybe have ADD (Attention Deficit Disorder) causing them to be unable to sit still, as well as Anxiety or impulsive actions. About one third of those affected will also show some symptoms of autism spectrum disorders that affect communication and social interaction.
Most Males affected and about one third of females affected by FXS will have physical features that become more prominent as they age. These include a long and narrow face, large ears, a prominent jaw and forehead, Unusually flexible fingers, and flat feet.