How a Chromosome Translocation Affects Gametogenesis in Human Male and Female? A Clinical Study Approach

Purpose: To study if females with balanced translocation (BT) have a normal ovarian response compared to normal karyotype XX women. And in male with BT, to determine if spermiogram is affected compared to normal XY karyotype men.

Methods: A retrospective analysis in a public IVF centre of 3249 karyotyped patients between 2008 and 2016, 2276 women, and 973 men. Cycle parameters, oocytes and embryo outcomes were examined. Spermiogram of 19 males with BT were compared with 93 normal XY patients. And 12 women with BT were compared with 93 control normal karyotype XX group (CN). An equivalent control group (EQc) of 12 patients was also selected to be accurate with the BT statistical contrast with normal karyotype in both members of the couple. Results of all cycles were compared.

Results: 19 males (1.9%) and 12 women (0.5%) had BT. Men with BT were older than CN group (37.86 ±5.62 vs. 40.26 ± 4.18; t57,590 = -3,169, p = 0.02). Motility (A+B) in fresh was not different (44.8 ± 17.96 vs. 42,28 ± 16.60 in control vs. pathologic; p=0.423) but had a significant lower concentration of spermatozoa (37.69 ± 37.36 vs. 23.49 ± 22.75 mill/ml; t65,04 = 3,191, p = 0.002). After capacitation, progressive motility (A + B) MSR (motile spermatozoa recovery) (70.86 ± 20.57 vs. 80.25 ± 18.94 control vs. pathologic; t292 = -2,589, p = 0.010). Women BT were older than CN (36.55±4.06 vs. 33.96±3.70; p<0.001), FSH was not different (6.54±1.30 vs. 6.39±1.72; p=0.618). BMI (body mass index) was higher in BT (26.73+5.36 vs. 24.32+3.98; p=0.011). Mature MII oocytes obtained was slightly higher in BT with no statistical difference (11.28±4.51 vs. 9.68±6.13; p=0.135), similar maturation rate (90.38% vs. 89.20%; p=0.602) and higher number of divided embryos with no statistical difference (9.03±3.53 vs. 7.28±5.25; p=0.09). Comparison with EQc to avoid differences with age, BMI and FSH values, showed no statistical differences in any of the studied parameters.

Conclusions: Men with a BT have poorer factors affecting sperm quality than control normal XY males. It is recommended to provide a karyotype in males with pathologic spermiogram prior to reproductive treatment. Women carriers of a BT do not have a diminished response pattern to COS (controlled ovarian stimulation) than CN of infertile women with normal karyotype XX. In both cases, an ICSI cycle with PGT and adequate genetic counseling are highly recommended.