A hemizygous loss-of-function variant in BCORL1 is associated with male infertility and oligoasthenoteratozoospermia.

Oligoasthenoteratozoospermia (OAT) is a common type of male infertility; however, its genetic causes remain largely unknown. Some of the genetic determinants of OAT are gene defects affecting spermatogenesis. BCORL1 (BCL6 corepressor like 1) is a transcriptional corepressor that exhibits the OAT phenotype in a knockout mouse model. A hemizygous missense variant of BCORL1 (c.2615T > G:p.Val872Gly) was reported in an infertile male patient with non-obstructive azoospermia (NOA). Nevertheless, the correlation between BCORL1 variants and OAT in humans remains unknown. In this study, we used whole-exome sequencing to identify a novel hemizygous nonsense variant of BCORL1 (c.1564G > T:p.Glu522*) in a male patient with OAT from a Han Chinese family. Functional analysis showed that the variant produced a truncated protein with altered cellular localization and a dysfunctional interaction with SKP1 (S-phase kinase-associated protein 1). Further population screening identified four BCORL1 missense variants in subjects with both OAT (1 of 325, 0.31%) and NOA (4 of 355, 1.13%), but no pathogenic BCORL1 variants among 362 fertile subjects. In conclusion, our findings indicate that BCORL1 is a potential candidate gene in the pathogenesis of OAT and NOA, expanded its disease spectrum and suggested that BCORL1 may play a role in spermatogenesis by interacting with SKP1.

Novel homozygous truncating variants in ZMYND15 causing severe oligozoospermia and their implications for male infertility.

Sequence variants of ZMYND15 cause azoospermia in humans, but they have not yet been reported in infertile men with severe oligozoospermia (SO). We performed whole-exome and Sanger sequencing to identify suspected causative variants in 414 idiopathic participating infertile men with SO or azoospermia. Three novel homozygous truncating variants in ZMYND15 were identified in three of the 219 (1.37%) unrelated patients with SO, including c.1209T>A(p.Tyr403*), c.1650delC (p.Glu551Lysfs*75), and c.1622_1636delinsCCAC (p.Leu541Profs*39). In silico bioinformatic analyses as well as in vivo and in vitro experiments showed that the ZMYND15 variants carried by the affected subjects might be the underlying cause for their infertility. One patient accepted intracytoplasmic sperm injection therapy, using his ejaculated sperm, and his wife successfully became pregnant. Our findings expand the disease phenotype spectrum by indicating that ZMYND15 variants cause SO and male infertility and suggest a possible correlation between the severity of male infertility caused by ZMYND15 variants and male age.

A novel homozygous frameshift mutation in MNS1 associated with severe oligoasthenoteratozoospermia in humans.

Oligoasthenoteratozoospermia (OAT) refers to the combination of various sperm abnormalities, including a decreased sperm count, reduced motility, and abnormal sperm morphology. Only a few genetic causes have been shown to be associated with OAT. Herein, we identified a novel homozygous frameshift mutation in meiosis-specific nuclear structural 1 (MNS1; NM_018365: c.603_604insG: p.Lys202Glufs*6) by whole-exome sequencing in an OAT proband from a consanguineous Chinese family. Subsequent variant screening identified four additional heterozygous MNS1 variants in 6/219 infertile individuals with oligoasthenospermia, but no MNS1 variants were observed among 223 fertile controls. Immunostaining analysis showed MNS1 to be normally located in the whole-sperm flagella, but was absent in the proband's sperm. Expression analysis by Western blot also confirmed that MNS1 was absent in the proband's sperm. Abnormal flagellum morphology and ultrastructural disturbances in outer doublet microtubules were observed in the proband's sperm. A total of three intracytoplasmic sperm injection cycles were carried out for the proband's wife, but they all failed to lead to a successful pregnancy. Overall, this is the first study to report a loss-of-function mutation in MNS1 causing OAT in a Han Chinese patient.

Network meta-analysis of antiepileptic drugs in focal drug-resistant epilepsy.

OBJECTIVE: To compare and rank the efficacy and acceptability of new antiepileptic drugs (AEDs) for patients with focal drug-resistant epilepsy. METHODS: PubMed, EMBASE, Cochrane databases and Clinicaltrials.gov were systematically searched from their inception through January 1, 2020, to identify trials evaluating AEDs for focal drug-resistant epilepsy. We included randomized controlled clinical trials (RCTs) comparing new AEDs with placebo or with other AEDs as adjunctive therapy for focal drug-resistant epilepsy. A Bayesian network meta-analysis was performed to determine efficacy and acceptability, as reflected by odds ratios (ORs), 95 % credible intervals (CrIs) with random-effects and consistent models. RESULTS: Sixty-two RCTs were included, involving 12,739 patients with focal drug-resistant epilepsy. Regarding the seizure-free rate (40 RCTs involving 9,136 patients), 8 AEDs were more efficacious than placebo, with lnORs ranging between 1.69 for brivaracetam (95 % CrI, 0.56-2.81) and 0.72 for pregabalin (95 % CrI, 0.12-1.32). Regarding the responder rate, all AEDs except oxcarbazepine were more efficacious than placebo, with lnORs ranging between 1.31 for levetiracetam (95 % CrI, 0.92-1.71) and 0.66 for carisbamate (95 % CrI, 0.17-1.14). Regarding acceptability (60 RCTs comprising 12,139 patients), 9 AEDs were inferior to placebo. Estimated from seizure-free rate, brivaracetam was ranked as the most efficacious AED based on cumulative probability plots and SUCRAs, with fatigue as the main adverse event. CONCLUSION: The results indicate that, based on seizure-free rate and all-cause discontinuation rate, brivaracetam is the most efficacious and acceptable AED, with mild adverse events and acknowledgement of potential publication bias.