Comparison of sperm morphology and nuclear sperm quality in SPATA16‐ and DPY19L2‐ mutated globozoospermic patients

Abstract

The aim of this study was to compare the sperm morphology and nuclear sperm quality (sperm aneuploidy and DNA fragmentation) in two groups of globozoospermic patients: DPY19L2‐mutated patients (n = 6) and SPATA16‐mutated patients (n = 2). Results for these two groups were also compared to a group of fertile men (n = 25). Fluorescence in situ hybridisation was performed for chromosomes X, Y and 18. Sperm DNA fragmentation was evaluated by TUNEL assay. Sanger sequencing was performed for mutations screening of DPY19L2 and SPATA16 genes. Sperm analysis revealed a classic phenotype of total globozoospermia in DPY19L2‐mutated group and a particular phenotype characterised by a predominance of double/multiple round‐headed (39.00 ± 4.2%) and multi‐tailed spermatozoa (26.00 ± 16.97%) in SPATA16‐mutated group. FISH analysis showed a significantly higher aneuploidy rate in globozoospermic patients compared to controls (p < 0.05), and a higher rate was observed in SPATA16‐mutated group compared to DPY19L2‐mutated group (p < 0.05). DNA fragmentation index was significantly higher in globozoospermic men compared to controls (p < 0.001), and there is no statistically significant difference between the two globozoospermic groups. We showed that SPATA16 defects could be associated with an abnormal meiosis leading to a particular morphological sperm defect of double/multiple round‐headed and multi‐flagella and a higher sperm aneuploidy rate than in case of DPY19L2‐defects in classic globozoospermia.

Genetic analyses of a large cohort of infertile patients with globozoospermia, DPY19L2 still the main actor, GGN confirmed as a guest player

“…homozygous deletion is still concordant with the literature varying from 19% (Koscinski et al 2011) to 75% (Harbuz et al 2011) and very close to a recent study with 35% of DPY19L2 homozygous deletions among a large cohort of 63 patients (Alimohammadi et al 2020). In fact several globozoospermia studies recruited only total globozoospermic patients (Zhu et al 2013;Shang et al 2019;Ghédir et al 2019) and observed a much higher rate of DPY19L2-positive diagnosis. This is consistent with the correlation that we observed here between the high rate of globozoocephalic spermatozoa and the presence of loss of function DPY19L2 variants or deletions.…”

Molecular Analysis of DPY19L2, PICK1 and SPATA16 in Italian Unrelated Globozoospermic Men

“…However, to date only a few globozoospermic patients have been examined. Most studies used the TUNEL assay to evaluate sperm DNA integrity and their results are generally in agreement with our findings, suggesting a high alteration of sperm DNA in globozoospermia [ 12 , 24 , 34 , 35 , 36 , 37 , 47 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 ]. Only a few studies claimed that globozoospermic men had similar chromatin and DNA integrity as fertile men [ 33 , 64 ].…”

“…Since SPATA16 is highly conserved in mammals, these findings could explain why no alterations of this gene were found in the globozoospermic patients examined in our study. However, analysis of SPATA16 exon 2 revealed a new deletion in two unrelated Tunisian men, which could explain the globozoospermic phenotype [ 46 , 47 ].…”

Globozoospermia: A Case Report and Systematic Review of Literature

“…Finally, 86 articles met our inclusion criteria and, therefore, were included in this systematic review ( Fig. 2 ) [ 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106…”

“…A total of 49 articles evaluated the prevalence and type of genetic abnormalities present in patients with globozoospermia [ 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 ] ( Table 3 ). The gene more frequently involved in the pathogenesis of globozoospermia is DPY19L2 and the mutation most frequently described is the deletion of the entire gene that, which has been reported to have a prevalence ranging from 22.2% [ 98 ] to 83.3% [ 105 ].…”