Paternal X could relate to arithmetic function; study of cognitive function and parental origin of X chromosome in Turner syndrome.

BACKGROUND

45,X Turner syndrome (TS) female subjects have visuospatial skill and social cognition deficits that may arise from X-linked imprinting. The aim of the present study was to compare phenotypic characteristics and neurocognitive pattern of 12 monosomic TS girls, according to X-linked imprinting.

METHODS

Microsatellite markers were used to determine the parental origin of the missing chromosome X. Wechsler Intelligence Scale for Children-Revised (WISC-R) was administered as measures of general intellectual functioning. The results were compared in TS patients with maternally derived X chromosome (Xm) and paternally derived X chromosome (Xp).

RESULTS

Six out of 12 patients (50%) had Xm, and the other six (50%) had Xp chromosome. There was no difference in the total, verbal and performance IQ score between the TS subgroups with Xm and Xp. When the WISC-R subtest score patterns were compared, the mean arithmetic scores were significantly poorer in the Xm TS than in the Xp TS.

CONCLUSION

In monosomic TS cases, paternal imprinting may predict arithmetic ability, on the other hand, reductionist consideration defined by genetic imprinting is not sufficient to confirm this. Further studies should be undertaken to clarify this situation.