Limited diagnostic value of lymphocytic karyotype in primary amenorrhea with streak gonads

Reproductive outcomes after preimplantation genetic testing in mosaic Turner syndrome: a retrospective cohort study of 100 cycles

PURPOSE

The purpose of this study is to explore the reproductive outcomes of women with Turner syndrome (TS) in preimplantation genetic testing (PGT) cycles.

METHODS

A retrospective study of 100 controlled ovarian stimulating cycles, 68 TS (sixty-four mosaic Turner syndrome (MTS) and four pure Turner syndrome (PTS)) women underwent PGT was conducted from 2013 to 2018.

RESULTS

Embryo X chromosome abnormal rates of TS women were significantly higher than women with normal karyotype (7.04 vs 1.61%, P<0.01). Cumulative live birth rates (CLBR) after PGT-NGS treatment were lower in TS than control (31.15 vs 45.59%, P<0.05). Clinical pregnancy rates per transfer (CPR), miscarriage rates (MR) and live birth rates per transfer (LBR) remained comparable between TS and control group. Reproductive outcomes (X chromosome abnormal rates, CPR, MR, LBR and CLBR) among low (<10%), medium (10-50%) and high (>50%) level 45,X mosaicism groups were not statistically different.

CONCLUSIONS

To avoid high risk of embryo X chromosome abnormalities, prenatal or preimplantation genetic testing should be recommended to mosaic or pure TS patients.

Sex Chromosome Mosaicism in the Gonads of DSD Patients: A Karyotype/Phenotype Correlation

Sex chromosome mosaicism results in a large clinical spectrum of disorders of sexual development (DSD). The percentage of 45,X cells in the developing gonad plays a major role in sex determination. However, few reports on the gonadal mosaic status have been published, and the phenotype is usually correlated with peripheral lymphocyte karyotypes, which makes the phenotype prediction imprecise. This study was conducted on 7 Egyptian DSD patients to demonstrate the effect of sex chromosome constitution of both blood lymphocytes and gonadal tissues on the phenotypic manifestations. Conventional cytogenetic and FISH analyses of blood lymphocytes were conducted, and laparoscopy with gonadal biopsy was performed for histopathologic examination and FISH analysis. Gonosomal mosaicism was detected in 3 patients who had a non-mosaic chromosome pattern in blood lymphocytes. Two patients showed the same type of sex chromosome mosaicism in both the blood and gonadal tissues but with different distributions. Two other patients revealed a non-mosaic pattern in both tissues. The present study elucidates the importance of examining sex chromosome mosaicism in gonadal tissues of DSD patients and highlights the critical role of 45,X mosaicism which can lead to serious effects during early gonadal organogenesis.

Sex chromosomal mosaicism in the gonads of patients with gonadal dysgenesis, but normal female or male karyotypes in lymphocytes

OBJECTIVES

In most cases, XX or XY gonadal dysgenesis remains genetically unexplained. In this pilot study we searched for sex-chromosomal mosaicism in gonads of patients with XX or XY gonadal dysgenesis of undetermined origin.

STUDY DESIGN

Gonadal tissues were analyzed by cytogenetic and interphase fluorescence in-situ hybridization (FISH) analyses in four patients with gonadal dysgenesis and normal female (46,XX) or male (46,XY) karyotypes in lymphocytes.

RESULTS

Cytogenetic and FISH analyses of the gonads demonstrated in three patients a sex-chromosomal mosaicism. Cytogenetic analysis of gonadal tissue of the fourth patient confirmed the result of the lymphocytes with 46,XX, but FISH analysis revealed in 17% of nuclei only one X-chromosome.

CONCLUSION

Our data indicate that sex-chromosomal mosaicism in gonads may be a frequent cause of gonadal dysgenesis despite of normal karyotypes in lymphocytes. Therefore, cytogenetic and FISH analyses of gonadal tissue can provide important information in unexplained cases of gonadal dysgenesis.