Novel mutation in ODF2 causes multiple morphological abnormalities of the sperm flagella in an infertile male

Numerous genes have been associated with multiple morphological abnormalities of the sperm flagella(MMAF),which cause severe asthenozoospermia and lead to male infertility,while the causes of approximately 50%of MMAF cases remain unclear.To reveal the genetic causes of MMAF in an infertile patient,whole-exome sequencing was performed to screen for pathogenic genes,and electron microscope was used to reveal the sperm flagellar ultrastructure.A novel heterozygous missense mutation in the outer dense fiber protein 2(ODF2)gene was detected,which was inherited from the patient’s mother and predicted to be potentially damaging.Transmission electron microscopy revealed that the outer dense fibers were defective in the patient’s sperm tail,which was similar to that of the reported heterozygous Odf2 mutation mouse.Immunostaining of ODF2 showed severe ODF2 expression defects in the patient’s sperm.Therefore,it was concluded that the heterozygous mutation in ODF2 caused MMAF in this case.To evaluate the possibility of assisted reproductive technology(ART)treatment for this patient,intracytoplasmic sperm injection(ICSI)was performed,with the help of a hypo-osmotic swelling test and laser-assisted immotile sperm selection(LAISS)for available sperm screening,and artificial oocyte activation with ionomycin was applied to improve the fertilization rate.Four ICSI cycles were performed,and live birth was achieved in the LAISS-applied cycle,suggesting that LAISS would be valuable in ART treatment for MMAF.

Clinical benefits of a modified Cryopiece system for cryopreservation of rare ejaculated and testicular spermatozoa for ICSI

Cryopreservation of rare testicular-retrieved spermatozoa for intracytoplasmic sperm injection(ICSI)in patients with severe oligozoospermia and azoospermia remains a major challenge in clinical practice.This study evaluated the Cryopiece system as a potential technique to cryopreserve rare human spermatozoa for ICSI.Small numbers of ejaculated(24 patients)and testicular(13 patients)spermatozoa were cryopreserved using the Cryopiece system.The total number of recovered spermatozoa and motility were assessed after thawing.Thirty-seven couples underwent ICSI using spermatozoa cryopreserved by the Cryopiece system,and ICSI outcomes(rates of fertilization,embryo cleavage,and clinical pregnancy)were evaluated.The average sperm post-thaw retrieval rate was 79.1%,and motility was 29.7%.Ejaculated spermatozoa had a higher post-thaw motility(32.5%)than testicular spermatozoa(21.8%;P=0.005).ICSI achieved a fertilization rate of 61.9%,embryo cleavage rate of 84.6%,and clinical pregnancy rate of 43.3%.The ICSI outcomes in the ejaculated and testicular frozen-thawed spermatozoa were similar.Assisted oocyte activation(AOA)after ICSI with motile(72.1%)or immotile(71.9%)spermatozoa resulted in a significantly higher fertilization rate than that when using motile spermatozoa without AOA(52.0%;P=0.005).However,AOA did not enhance the clinical pregnancy rate(55.6%or 40.0%vs 35.3%;P=0.703).The Cryopiece system is simple and useful for the cryopreservation of small numbers of ejaculated or testicular spermatozoa for ICSI in patients with severe oligozoospermia or nonobstructive azoospermia.