Association of parental origin with clinical profile in klinefelter syndrome

Several genomic imprinting mechanisms have been postulated to report the parent-of-origin in Klinefelter syndrome. It was stated in the literature, parental origin has an effect on behavioral phenotype of Klinefelter individuals, but the association of the same on clinical profile was less reported. The detailed clinical phenotype when studied with the known origin of extra X may possibly explain the imprinting effect that may be helpful to derive diagnostic criteria in the syndrome. In the present study, we investigated the parental-of-origin of extra X chromosome in Klinefelter syndrome probands with an aim to report the association between the phenotype with that of its karyotype and the parental origin of supernumerary X.

Seventy two probands that were referred to division of Human Genetics, St.John's Medical College, Bangalore with variable complaints and phenotypic features were diagnosed with informed consent as Klinefelter syndrome with a confirmed karyotype. The Karyotype was prepared by peripheral lymphocyte culture and GTG banding method. The parental origin was studied in 9 families of Klinefelter probands with standard protocol for GENE SCAN using X-chromosome specific Short Tandem Repeat markers. The outcome was analyzed to determine the parental origin by GENE MAPPER.

STATISTICAL ANALYSIS was conducted to ascertain the significance of parental origin of supernumerary X with the phenotypic profile with confirmed karyotype.

Seven of nine probands had 47, XXY karyotype and 2 were mosaic with 47,XXY/46,XY karyotype. Five probands had their supernumerary X from maternal side and four were paternally derived. Sixteen features as framed proforma were tabulated against the originated X in Klinefelter probands. 55.56% of Klinefelter stigmata were seen in prob and who had maternally derived X and the rest were with paternal X.

The findings of the present study points on parent-of-origin effect on clinical profile and indicate that the imprinted X chromosome genes show differential effect general and systemic traits.