INTRAUTERINE DIAGNOSIS OF SEX-CHROMOSOME ANEUPLOIDY

Objective: To provide current information on sex chromosome aneuploidi es to obstetricians who encounter such diagnoses and who counsel prosp ective parents faced with the prenatal diagnosis of a sex chromosome a neuploidy. Data Sources: Unbiased information about the natural course of sex chromosome aneuploidy has become available only in the last fe w years. Current knowledge is based on seven prospective studies on un selected individuals with sex chromosome aneuploidy identified 20-30 y ears ago. All literature on sex chromosome aneuploidy was reviewed. Ka ryotypes specifically addressed included the following: 47,XXY, 47,XXX , 47,XYY 45,X, 45,X/46,XX, 46,XX/47,XXX, and 46,XY/47,XXY. Methods of Study Selection: The international studies followed the affected subje cts from birth to young adulthood. All published reports, case studies , and articles were reviewed. Tabulation, Integration, and Results: Al l prospective studies were included in the course of determining neces sary information for obstetricians and prospective parents. Points add ressed for each of the aneuploid karyotypes included expected phenotyp e, reproductive competence, developmental risks, and intervention ther apies. Conclusion: Information about sex chromosome aneuploidy fan ass ist obstetricians in providing accurate and comprehensive genetic coun seling to parents of affected fetuses, and thereby facilitate the proc ess of making an informed decision about pregnancy management.