A 19-year-old woman presented with primary amenorrhea, sho stature, webbed neck and widely spaced nipples. Examination showed weak pulses in lower extremity and streak ovaries, raised FSH, no oocyte in histology of ovary. Karyotype most likely to be present:KCET 12; JIPMER 12; AIIMS 13; PGI 13
45XO
47XXY
46XY
46XX
Ans. 45XOTurner's syndrome is a genetic disease with a karyotype of 45, X or 46, XX/45, X (mosaicism) or other structural abnormalities of X chromosomes.With conventional chromosomal studies, about 50% of Turner syndrome patients show a 45,X pattern.* Mosaicism of 45,X with other cell lines such as 46,XX, 46,XY, or 47,XXX are common.* Structural abnormalities of an X chromosome (deletions, rings, or translocations), either isolated or mosaic with a 45,X or 46,XX cell line, are also seen.* With modern cytogenetic techniques, mosaicism is increasingly being detected.* The sho stature in Turner syndrome appears to be caused by the absence of one copy of the SHOX gene, which is located on the sho arm of the X chromosome.