Ullrich-Turner syndrome: Seven pregnancies in an apparent 45,X woman

Abstract

A 37-year-old woman was referred for genetic counseling after termination of her probable seventh pregnancy. Ultrasound examination at 13 weeks of gestation had shown a fetus with bilateral cystic hygromas. A transabdominal amniocentesis confirmed 45,X karyotype in the fetus. The patient had marked short stature and a 45,X chromosome constitution in blood lymphocytes. Subsequently she had a hysterectomy and oophorectomy. Tissue of representative sites of the pathological specimen showed a 45,X chromosome constitution. However, molecular analysis of 8 sites from the uterus and ovaries, and of skin fibroblasts with X-chromosome microsatellites showed the presence of only one allele, except for the microsatellite DXS996 which demonstrated 2 alleles (155 bp and 161 bp) in ovarian tissue. The lymphocytes from the mother and her only son demonstrated the same single allele (161 bp). We conclude that molecular analysis of lymphocytes and of tissue is necessary for detecting low-level mosaicism in apparently homogeneous 45,X women.

Outcomes of spontaneous and assisted pregnancies in Turner syndrome: the U.S. National Institutes of Health experience

“…A fertile, 45,X woman may produce oocytes containing either a normal, single X or no sex chromosome, resulting in zygotes that are either eukaryotic or 45,X. In the latter case, the gestation is unlikely to survive (40), but in the rare cases of survival, the resulting zygote would have TS (26-27). On the other hand, if pregnancy occurs in a woman with a structurally abnormal X chromosome, there is a distinct possibility of passing the abnormal chromosome to offspring, which could then have phenotype similar to the mother.…”

Meiosis and sex chromosome aneuploidy: how meiotic errors cause aneuploidy; how aneuploidy causes meiotic errors

“…Possibly, then, rare Turner syndrome individuals who have had pregnancies are mosaics, with germ cells having a 46,XX sex chromosome constitution. This would be consistent with several reports in which exhaustive analyses of different tissues have identified a rare, second cell line in an otherwise non-mosaic 45,X female [47].…”

A clinical and molecular study of 26 females with Xp deletions with special emphasis on inherited deletions

“…Fertility has been reported in 45,X women, but in virtually all cases that are investigated in detail evidence of mosaicism has been detected (Magee et al 1998). Cryptic mosaicism could also be used to explain the variable phenotype in females with an Xp deletion.…”