Sperm FISH analysis in two healthy infertile brothers with t(15;18) unbalanced translocation: Implications for genetic counselling and reproductive management

Chromosomal scan of single sperm cells by combining fluorescence-activated cell sorting and next-generation sequencing

PURPOSE

The purpose of this study was to develop a feasible approach for single sperm isolation and chromosome analysis by next-generation sequencing (NGS).

METHODS

Single sperm cells were isolated from semen samples of normozoospermic male and an infertile reciprocal translocation (RcT) carrier with the 46,XY,t(7;13)(p12;q12.1) karyotype using the optimized fluorescence-activated cell sorting (FACS) technique. Genome profiling was performed using NGS.

RESULTS

Following whole-genome amplification, NGS, and quality control, the final chromosome analysis was performed on 31 and 6 single cell samples derived from the RcT carrier and normozoospermic male, respectively. All sperm cells from normozoospermic male showed a normal haploid 23-chromosome profile. For the RcT carrier, the sequencing data revealed that 64.5% of sperm cells harbored different variants of chromosome aberrations, involving deletion of 7p or 7q, duplication of 7p, and duplication of 13q, which is concordant with the expected chromosome segregation patterns observed in balanced translocation carriers. In one sample, a duplication of 9q was also detected.

CONCLUSIONS

We optimized FACS protocol for simple and efficient isolation of single human sperm cells that subsequently enabled a successful genome-wide chromosome profiling and identification of segmental aneuploidies from these individual cells, following NGS analysis. This approach may be useful for analyzing semen samples of infertile men or chromosomal aberration carriers to facilitate the reproductive risk assessment.

Impact of chromosomal translocations on male infertility, semen quality, testicular volume and reproductive hormone levels

OBJECTIVE

To analyse the relationship between male infertility and chromosomal translocations, and the influence of different types of chromosomal translocations on semen quality, testicular volume and hormone levels.

METHODS

A retrospective cohort of infertile men was recruited for chromosomal analysis using standard Giemsa stain banding. Physical examinations, semen analysis, hormonal analysis and the detection of azoospermia factor (AZF) microdeletions were carried out. Men with normal fertility were used as controls.

RESULTS

Among the 1056 infertile men, 22 had chromosomal translocations (2.1%), including seven with Robertsonian translocations (0.7%), 11 with autosome-autosome reciprocal translocations (1.0%) and four with gonosome-autosome reciprocal translocations (0.4%). Left and right testicular volumes of patients with chromosomal translocations were significantly smaller than those in the fertile control group. There were no significant differences in hormone levels between patients with chromosomal translocations and fertile controls, except for significantly lower testosterone levels in patients with Robertsonian and gonosome-autosome reciprocal translocations compared with the controls. All AZF microdeletion analyses showed normal results.

CONCLUSIONS

Chromosomal translocations may cause reductions in testicular volume and testosterone level, which may impact spermatogenesis, resulting in azoospermia or oligozoospermia and male infertility.

Impact of reciprocal translocation t (18; 21) on male infertility and embryo development: lessons from an oocyte-donating ICSI cycle

PURPOSE

To report the outcome of intracytoplasmic sperm injection (ICSI) cycles of an oligozoospermic man with reciprocal translocation.

METHODS

Two ICSI cycles were given to a 29-year-old man with severe oligozoospermia and reciprocal translocation t(18;21)(p11;q21) and his wife. In the first cycle, no sperm were found in his semen and all 15 oocytes retrieved were donated to another infertile couple suffering from oligozoospermia and premature ovarian failure. In the second cycle, sperm from the husband's ejaculate were used to fertilize 13 retrieved oocytes.

RESULTS

Eleven embryos were acquired and a healthy girl was born in the oocyte-donated ICSI cycle. In the second cycle, 6 embryos were acquired and only biochemical pregnancy was achieved after three times of embryo transfer.

CONCLUSIONS

By the unusual oocyte-donating ICSI procedures, impact of the new reported reciprocal translocation t (18; 21) (p11; q21) on male fertility and embryo development was suggested.