High rate of premature chromosome condensation in human oocytes following microinjection with round-headed sperm: Case report

Abstract

A young couple proceeded to three ICSI treatment cycles because of male infertility. The semen samples varied between 10 x 10(6) and 36 x 10(6)/ml, 38 and 51% progressive motility but 0% normal morphology. Different types of sperm heads, mostly round-headed with varying spherical appearance (86%) were presented beside acephalic sperm (pinheads; 12%), both one- or two-tailed and the former also without a tail. Very few sperm (2%) exhibited slightly oval-shaped heads. Electron microscopy revealed the absence of the acrosome combined with disturbance of the chromatin condensation among the round-headed sperm. In all three cycles, the fertilization rate using the round-headed sperm fraction was very low with the best result of 2/18 (11%) two-pronucleate oocytes and one one-pronucleate oocyte obtained in the second ICSI cycle. The three oocytes cleaved and were transferred in the 3-4-cell stage without achieving a pregnancy. Of the 29 unfertilized and prepared oocytes from the last two cycles, 27 were informative and revealed the maternal metaphase II chromosomes in the haploid range and a high rate (85%) of premature chromosome condensation (PCC) of the sperm nucleus with remarkable variation in the degree of condensation. Thus, it appears that nearly all round-headed sperm from this patient were incapable of oocyte activation after ICSI, which could be due to non-release (or absence) of an activating factor. As a consequence, PCC was induced in the sperm nuclei by the chromosome condensing factors which were still active in the oopasm of the arrested oocytes.

Contributions of cytogenetic and ultrastructural exploration in fertility prognosis for subjects with globozoospermia

“…Nos résultats sont en accord avec l'étude réalisée par Schmiady et al qui rapportent un taux de fécondation de 11 % en cas de globozoospermie totale [19]. Ce faible taux de fécon-dation s'explique par la difficulté que présentent ces spermatozoïdes à activer l'ovocyte, avec probablement une insuffisance en facteurs d'activation ovocytaire.…”

Intracytoplasmic Sperm Injection – Factors Affecting Fertilization

“…Immature cytoplasm is believed to make sperm susceptible to a high incidence of PCC after insemination because of the inability of these immature oocytes to undergo oocyte activation [85]. The incidence of sperm PCC reported in the literature ranges from 10.1 to 85 % [86,87], with higher values noted in cases of round headed sperm injection as they fail to activate the oocyte. Furthermore, other studies suggest a correlation between fertilization outcome post-ICSI and percentage of sperm with protamine deficiency [88].…”

Mutation of β-glucosidase 2 causes glycolipid storage disease and impaired male fertility

“…To determine if mutations in human GBA2 were the cause of globozoospermia, we sequenced the coding regions of the gene in affected males of 3 unrelated families from Britain (38), Canada (39), and Germany (40). No mutations in GBA2 were detected in these subjects, suggesting that loss of this enzyme does not underlie all cases of globozoospermia in human males.…”