Objectives: To examine the underlying cognitive abilities of girls with Turner syndrome, as well as to examine the nature, direction and extent of discrepancies between verbal and performance functioning.
Method: Standard tests of intellectual functions (WISC-R and WAIS-R) were administered to 28 girls with Turner syndrome. Subjects varied in age between one year and nine years.
Results: The findings indicate that there is strong, though not entirely consistent, tendency among Turner subjects to show depressed performance scores in comparison with their verbal scores. There was also a tendency toward lower levels of overall cognitive functioning among girls with the classic karyotype over those with mosaic karyotypes.
Conclusions: These findings are in keeping with international findings concerning the intellectual functioning, of girls with Turner syndrome. The findings support the view that the X chromosome is important in regulating the overall balance within the intellectual functioning between verbal and performance domains.