Neurocognitive and Psychosocial Phenotypes Associated with Turner Syndrome
Bruce G. Bender
Mary G. Linden
National Jewish Center for Immunology and Respiratory Medicine University of Colorado School of Medicine
Turner syndrome (TS) occurs in about 1 of 2,500 live female births. The incidence of TS is markedly higher at conception, as only about 1% survive to birth ( Hook & Warburton, 1983). The karyotype of TS females can be either a pure 45,X cell line or partial monosomy X, including a variety of sex chromosome abnormality (SCA) mosaics involving monosomy X. The physical phenotype typically includes short stature and ovarian dysgenesis, and may include cardiovascular malformations, renal malformations, webbing of the neck, low posterior hairline, increased carrying angle, shieldlike chest, triangular facies, high-arched palate, short fourth metacarpal, hyperconvexity of the fingernails, and multiple nevi. Some of these TS complications, such as cardiovascular and renal malformations, require close medical scrutiny and occasional intervention. TS patients are increasingly being offered human growth hormone therapy aimed at increasing stature. Secondary sex characteristics are sometimes achieved and maintained through supplemental estrogen therapy. For more extensive discussion of the TS physical phenotype, see chapter 9 in this volume.
Attempts to define the psychological phenotype of TS have inspired a considerable number of investigations, hypotheses, and speculations over the past 30 years. It is the purpose of this chapter to examine the evolution of these definitions. The first descriptions of psychological characteristics have undergone repeated modifications as investigations have become more