Neurodevelopmental and psychosocial aspects of Turner syndrome

Turner syndrome (TS) is the complex phenotype of human females with complet e or partial absence of the second sex chromosome, or monosomy X. A charact eristic neurocognitive and psychosocial profile has also been described in TS females, Typically, specific deficits in visual-spatial/ perceptual abil ities, nonverbal memory function, motor function, executive function, and a ttentional abilities occur in TS children and adults of varying races and s ocioeconomic status. TS-associated psychosocial difficulties occur in the a reas of maturity and social skills. We hypothesize that a subset of the neu rocognitive deficits (visual-spatial/perceptual abilities) are genetically determined and result from abnormal expression of one or more X chromosome genes. In addition, a different subset of these neurocognitive deficits (me mory, reaction time, and speeded motor function) result from estrogen defic iency and are at least somewhat reversible with estrogen treatment. The TS- associated psychosocial problems are most likely linked to these core neuro cognitive deficits and do not reflect a separate and independent component of the syndrome. Turner syndrome research has progressed significantly over the last decade. The field has moved from descriptive reports based on sin gle individuals or small clinical samples to the use of experimental design s with larger, more diverse and representative samples. This degree of vari ability among individuals with Turner syndrome in ail domains (karyotype or genetic constitution, physical attributes, neurocognitive and social funct ioning) suggests the need to identify risk and protective factors contribut ing to the heterogeneity in the phenotype. Active education about TS and pa rticipation in patient advocacy groups such as the Turner Syndrome Society of the United States (http://www. Turner-syndrome-us.org/) has provided new information for TS adults and families as well as a supportive peer group. (C) 2000 Wiley-Liss, Inc.