Deficits in space-form perception in patients with sex chromosome mosaicism (45,X/46,XY)

Several studies have shown that selective deficits in space-form perception are found in patients with Turner's syndrome, associated with 45,X or a structural anomaly of an X chromosome. The authors sought to determine whether significant deviations from normal or from Turner's syndrome (relative to space perception) occur when a Y chromosome is present. The four patients studied, aged between 4 1/2 and 24 years, had a karyotype of 45,X/46,XY and a phenotype ranging from sexual ambiguity at birth to typical Turner's syndrome. Although all were in the normal intelligence range (IQ 80 or above), on testing they demonstrated below-average ability in tasks involving visualization of spatial forms, and their drawings were generally immature. The results suggest that patients with sex chromosome mosaicism X/XY may have similar deficits in space-form perception and orientation to those previously demonstrated in Turner's syndrome.