APA Dictionary of Psychology

a chromosomal disorder, specific to females, marked by the absence of all or a part of one of the two X (female) chromosomes. The effects include gonadal dysgenesis (underdevelopment or absence of primary and secondary sex characteristics), infertility, and various other abnormalities (e.g., short stature, lack of menstruation). Although the disorder is genetic, it is not inherited, occurring instead as a random event during cell division in early fetal development. See also Noonan syndrome. [reported in 1938 by Henry H. Turner (1892–1970), U.S. endocrinologist]