Their ovaries do not develop normally and they do not ovulate. The few o cytes that they produce are destroyed by the time they are two. They are in a sense postmenopausal from early childhood and are sterile. They also have a higher than average incidence of thyroid disease. In some individuals, there is slight mental retardation.
Turner syndrome is rare.
Current estimates of its frequency range from 1 in 3,000 female infants to 1 in 5,000. If diagnosed in early childhood, regular injections of human growth hormones can increase their stature by a few inches. Beginning around the normal age of puberty, estrogen replacement therapy can result in some breast development and menstruation. These treatments allow Turner syndrome women to appear relatively normal. They have normal development of sexual characteristics and are fertile.