A case of primary ciliary dyskinesia treated with ICSI using testicular spermatozoa: case report and a review of the literature

Three cases of sperm immobility for intracytoplasmic sperm injection using testicular sperm

Introduction

Sperm immobility is a condition in which sperm are viable but not motile. We reported three patients with sperm immobility, who underwent testicular sperm extraction-intracytoplasmic sperm injection.

Case presentation

In case 1, a 32-year-old patient with sperm immobility had previously undergone intracytoplasmic sperm injection with ejaculated sperm; however, pregnancy was unsuccessful. testicular sperm extraction-intracytoplasmic sperm injection was performed at our clinic, and pregnancy was achieved. In case 2, a 23-year-old patient with clinical varicocele whose semen analysis revealed sperm immobility underwent varicocelectomy, without improvement. Using the hypo-osmotic swelling test technique, testicular sperm extraction-intracytoplasmic sperm injection was performed; however, pregnancy was not achieved. In case 3, a 44-year-old patient with sperm immobility underwent testicular sperm extraction, and motile sperm were retrieved. testicular sperm extraction-intracytoplasmic sperm injection using these sperm resulted in pregnancy.

Conclusion

Although testicular sperm extraction-intracytoplasmic sperm injection is not considered a solution in patients with sperm immobility, pregnancies were achieved. testicular sperm extraction-intracytoplasmic sperm injection may be successful in some cases in which ejaculated sperm intracytoplasmic sperm injection is unsuitable.

CCDC40 mutation as a cause of infertility in a Chinese family with primary ciliary dyskinesia

TRIAL DESIGN

Primary ciliary dyskinesia (PCD) is a genetical disease that inherited in an autosomal-recessive way. Its clinical manifestations (such as male infertility) are mainly caused by defects of motion-related cilia that encoded by mutated genes. Although some mutation has been verified, a number of mutations of PCD remain elusive. The main purpose of this study is to identify mutant genes in a Chinese family with PCD, and to verify the safety and effectiveness of intracytoplasmic sperm injection (ICSI) of infertility caused by PCD.

METHODS

Imaging examination was used to exclude pulmonary inflammation and visceral translocation. Semen analysis was used to assess the quality of the proband's sperm. Transmission electron microscopy (TEM) was conducted to assess the ultrastructure of flagella and cilia. Targeted next generation sequencing and Sanger sequencing and qPCR (real-time quantitative polymerase chain reaction detecting system) were applied to identified mutation of Chinese Family suspected of having PCD. Viable sperm were selected by hypo-osmotic swelling test (HOST) for ICSI.

RESULTS

We report 2 novel mutations in CCDC40 gene (c.1259delA and EX17_20 deletion) resulted in immobility of sperm and infertility of the proband. These mutations were confirmed in the proband's sister (heterozygous) and his parents (recessive carrier) by Sanger sequencing and qPCR. All the spermatozoa from the proband were immotile. Ultrastructural defects were found in flagella and cilia of proband and his sister. Viable sperms were selected by HOST for ICSI and fertilized 9 of 21 eggs. Two frozen embryos were transplanted and a healthy 3500 g boy was delivered at 40 + 4 weeks' gestation. And then, we summarized the genes related to PCD and the mutant sites of CCDC40 gene.

CONCLUSION

We reported 2 novel mutants in CCDC40 gene (c.1259delA and EX17_20 deletion), which could be candidates for genetic diagnosis in PCD patients. The combination of targeted next generation sequencing and Sanger sequencing may be a useful tool to diagnose PCD. ICSI is a considerable method in treatment of infertility caused by PCD.

Genetic underpinnings of asthenozoospermia

Asthenozoospermia (AZS), defined by reduced motility or absent sperm motility, is one of the main causes of male infertility. This condition may be divided into isolated AZS in the absence of other symptoms and syndromic AZS, which is characterized by several concurrent clinical symptoms. Sperm motility depends on fully functional flagellum, energy availability, and the crosstalk of several signaling pathways; therefore, mutations in genes involved in flagellar assembly and motile regulation can cause AZS. Thus, it is crucial to understand the genetic causes and mechanisms contributing to AZS. In this review, we summarize the current knowledge about the particular genes and mechanisms involved in intact flagellum, energy availability, and signaling transduction that could cause human AZS and discuss the respective gene defects known to be responsible for these abnormalities. Additionally, we discuss intracytoplasmic sperm injection outcomes and offspring health where available in these cases.

Ultrastructural Sperm Flagellum Defects in a Patient With CCDC39 Compound Heterozygous Mutations and Primary Ciliary Dyskinesia/Situs Viscerum Inversus

Introduction: Primary ciliary dyskinesia (PCD) is a rare autosomal recessive disease characterized by structural or functional motile cilia abnormalities. Up to 40 different genes seem, at the moment, to be involved in the pathogenesis of PCD. A number of ultrastructural defects have also been reported in sperm flagella, but the sperm mitochondrial membrane potential (MMP) has never been described in these cases.

Aim: The aim of this study was to report the sperm MMP and ultrastructural abnormalities of the sperm flagella found in a patient with PCD and situs inversus (Kartagener syndrome) and its characterization from the genetic point of view.

Methods: Transmission electronic microscopy (TEM) analysis was used to evaluate flagella ultrastructure. The genetic testing was performed by next-generation sequencing. Sperm DNA fragmentation and MMP were also evaluated by flow cytometry.

Results: We report here the case of an 18-year-old male patient with PCD and situs inversus and severe oligo-astheno-teratozoospermia. TEM analysis of his spermatozoa showed an abnormal connecting piece. The mid piece appeared abnormally thickened, with cytoplasmic residue, dysplasia of fibrous sheath, loss of the outer dynein arms (ODAs), truncated inner dynein arms, and supernumerary outer fibers. The percentage of spermatozoa with fragmented DNA was normal, whereas a high percentage of spermatozoa had low MMP, suggesting an altered mitochondrial function. The genetic analysis showed the presence of c.610-2A > G, p.Arg811Cys compound heterozygous mutations in the CCDC39 gene.

Conclusion: The case herein reported suggests that the high percentage of sperm with low MMP may play a role in the pathogenesis of asthenozoospermia in patients with Kartagener syndrome. In addition, we report, for the first time, the missense variant p.Arg811Cys in the CCDC39 gene in a patient with Kartagener syndrome. Although in silico analysis predicts its damaging potential, its clinical meaning remains unclear.

Sperm defects in primary ciliary dyskinesia and related causes of male infertility

The core axoneme structure of both the motile cilium and sperm tail has the same ultrastructural 9 + 2 microtubular arrangement. Thus, it can be expected that genetic defects in motile cilia also have an effect on sperm tail formation. However, recent studies in human patients, animal models and model organisms have indicated that there are differences in components of specific structures within the cilia and sperm tail axonemes. Primary ciliary dyskinesia (PCD) is a genetic disease with symptoms caused by malfunction of motile cilia such as chronic nasal discharge, ear, nose and chest infections and pulmonary disease (bronchiectasis). Half of the patients also have situs inversus and in many cases male infertility has been reported. PCD genes have a role in motile cilia biogenesis, structure and function. To date mutations in over 40 genes have been identified cause PCD, but the exact effect of these mutations on spermatogenesis is poorly understood. Furthermore, mutations in several additional axonemal genes have recently been identified to cause a sperm-specific phenotype, termed multiple morphological abnormalities of the sperm flagella (MMAF). In this review, we discuss the association of PCD genes and other axonemal genes with male infertility, drawing particular attention to possible differences between their functions in motile cilia and sperm tails.

Novel DNAAF6 variants identified by whole-exome sequencing cause male infertility and primary ciliary dyskinesia

PURPOSE

To identify the genetic cause of patients with primary ciliary dyskinesia (PCD) and male infertility from two unrelated Han Chinese families.

METHODS

We conducted whole-exome sequencing of three individuals with PCD and male infertility from two unrelated Chinese families, and performed a targeted look-up for DNAAF6 variants in our previously reported cohort of 442 individuals (219 with isolated oligoasthenospermia and 223 fertile controls). Ultrastructural and immunostaining analyses of patients' spermatozoa were performed. The pathogenicity of the variants was validated using patient's spermatozoa and HEK293T cells. Intracytoplasmic sperm injection (ICSI) treatment was conducted in two patients.

RESULTS

We identified one novel hemizygous frameshift variant (NM_173494, c.319_329del: p.R107fs) of DNAAF6 gene (previously named PIH1D3) in family 1 and one novel hemizygous missense variant (c.290G>T: p.G97V) in family 2. No hemizygous deleterious variants in DNAAF6 were detected in the control cohort of 442 individuals. Ultrastructural and immunostaining analyses of patients' spermatozoa showed the absence of outer and inner dynein arms in sperm flagella. Both variants were proven to lead to DNAAF6 protein degradation in HEK293T cells. Both patients carrying DNAAF6 variants underwent one ICSI cycle and delivered one healthy child each.

CONCLUSION

We identified novel DNAAF6 variants causing male infertility and PCD in Han Chinese patients. This finding extended the spectrum of variants in DNAAF6 and revealed new light on the impact of DNAAF6 variants in sperm flagella.

Patients with severe asthenoteratospermia carrying SPAG6 or RSPH3 mutations have a positive pregnancy outcome following intracytoplasmic sperm injection

PURPOSE

To investigate the relation between mutations in ciliopathy-related SPAG6 and RSPH3 and male infertility with severe asthenoteratospermia characterized by multiple flagellar malformations and reveal the intracytoplasmic sperm injection (ICSI) outcomes of those primary ciliary dyskinesia (PCD) patients.

METHODS

Whole-exome sequencing was applied to identify the pathogenic genes for the five PCD patients. The ICSI outcomes of those patients were compared with eight DNAH1-mutated patients and 215 oligo-asthenospermia (OAT) patients.

RESULTS

We identified, for the first time, the compound heterozygous SPAG6 mutations (c.143_145del: p.48_49del, c.585delA: p.Lys196Serfs*6) in a sporadic PCD patient. Further, a novel homozygous nonsynonymous RSPH3 mutation (c.C799T: p.Arg267Cys) was identified in another PCD patient with consanguineous parents. The pathogenicity of these mutations in the assembly of sperm flagella was confirmed by flagellar ultrastructure analysis, immunofluorescence, and quantitative real-time PCR. All five patients underwent six ICSI cycles. The fertilization rate, blastocyst development rate, and clinical pregnancy rate were 69.3%, 50.0%, and 66.7%, respectively. Four of the five couples, including the subjects carrying mutations in SPAG6 or RSPH3, got healthy children born after ICSI. Additionally, the ICSI outcomes of the five PCD couples were statistically comparable with those of the eight DNAH1-mutated couples and the 215 OAT couples.

CONCLUSIONS

Mutations in ciliopathy-related SPAG6 and RSPH3 cause severe asthenoteratospermia characterized by multiple flagellar malformations, resulting in sterility. ICSI is an optimal management with a positive pregnancy outcome.