Endocrine Abstracts

Introduction: Turner syndrome is well known, but prognosis for 45,X/46,XX mosaicism under 30% of aneuploidy has not been established. We realised a retrospective study among women aged 21–43 years, to evaluate differences in clinical features and biological parameters between patients who had sex chromosome mosaicism diagnosed incidentally and controls women.

Material and methods: Among infertile population, 71 women with sex chromosome mosaicism (45,X/46,XX) range from 4 to 28% were compared to 72 controls (46,XX). We evaluated clinical changes for menarche, menses, premature ovarian failure, height and body mass index. Assessments for early-follicular-phase blood values of FSH, LH, inhibin B, estradiol and TSH were measured at our laboratory. At last, we wondered if spontaneous fertility and pregnancy outcomes were influenced by such an aneuploidy.

Results: Eight percentage or more of aneuploidy was responsible for a lower height compared to controls (160±6 vs 165±6 cm; P=0.01). Sex chromosome aneuploidy was positively correlated to BMI (P=0.0001) and negatively correlated to menarche (P=0.045); moreover, menarche occured earlier when aneuploidy reached 10% or more (12.3±1.0 vs 13.5±1.3 years; P=0.01). There was no difference between the groups for FSH (8.41±2.6 UI/l versus 8.28±4.0 UI/l; P=0.85), LH, estradiol (50.6±23.7 vs 51.7±32.1 pg/ml; P=0.81), Inhibin B (55.5±36.5 vs 57.4±33.7 pg/ml; P=0.80) and TSH (1.74±0.8 vs 1.83±1.1 micUI/ml; P=0.64). Premature ovarian failure incidence did not differ between the two groups. Spontaneous abortions were more frequent in study group (2.0±0.9 vs 1.2±0.4; P=0.01) and recurrence was positively correlated to aneuploidy percentage (P=0.008).

Conclusion: Sex chromosome mosaicism is responsible for clinical changes since 8% of aneuploidy, corresponding to main phenotypic features of Turner syndrome.