scholarly journals Biallelic mutations in M1AP are a frequent cause of meiotic arrest leading to male infertility

2019 ◽  
Author(s):  
Margot J. Wyrwoll ◽  
Şehime G. Temel ◽  
Liina Nagirnaja ◽  
Manon S. Oud ◽  
Alexandra M. Lopes ◽  
...  

AbstractMale infertility affects ∼7% of men in Western societies, but its causes remain poorly understood. The most clinically severe form of male infertility is non-obstructive azoospermia (NOA), which is, in part, caused by an arrest at meiosis, but so far only few genes have been reported to cause germ cell arrest in males. To address this gap, whole exome sequencing was performed in 60 German men with complete meiotic arrest, and we identified in three unrelated men the same homozygous frameshift variant c.676dup (p.Trp226LeufsTer4) in M1AP, encoding meiosis 1 arresting protein. Then, with collaborators from the International Male Infertility Genomics Consortium (IMIGC), we screened a Dutch cohort comprising 99 infertile men and detected the same homozygous variant c.676dup in a man with hypospermatogenesis predominantly displaying meiotic arrest. We also identified two Portuguese men with NOA carrying likely biallelic loss-of-function (LoF) and missense variants in M1AP among men screened by the Genetics of Male Infertility Initiative (GEMINI). Moreover, we discovered a homozygous missense variant p.(Pro389Leu) in M1AP in a consanguineous Turkish family comprising five infertile men. M1AP is predominantly expressed in human and mouse spermatogonia up to secondary spermatocytes and previous studies have shown that knockout male mice are infertile due to meiotic arrest. Collectively, these findings demonstrate that both LoF and missense M1AP variants that impair its protein cause autosomal-recessive meiotic arrest, non-obstructive azoospermia and male infertility. In view of the evidence from several independent groups and populations, M1AP should be included in the growing list of validated NOA genes.

Author(s):  
М.В. Андреева ◽  
М.И. Штаут ◽  
Т.М. Сорокина ◽  
Л.Ф. Курило ◽  
В.Б. Черных

Обследованы 19 мужчин с нарушением фертильности, носителей транслокаций rob(13;14) и rob(13;15). Показано, что нарушение репродуктивной функции обусловлено блоком сперматогенеза в профазе I мейоза, приводящего к азооспермии или олигоастенотератозооспермии и мужскому бесплодию. We examined 19 infertile men, carriers of translocations rob (13;14) and rob (13;15). We assume that fertility problems are resulted from spermatogenesis impairment because of meiotic arrest at prophase I stages, that leads to azoospermia or oligoastenoteratozoospermia and male infertility.


2020 ◽  
pp. jmedgenet-2020-107042
Author(s):  
Chencheng Yao ◽  
Chao Yang ◽  
Liangyu Zhao ◽  
Peng Li ◽  
Ruhui Tian ◽  
...  

BackgroundThe genetic causes of human idiopathic non-obstructive azoospermia (NOA) with meiotic arrest remain unclear.MethodsTwo Chinese families with infertility participated in the study. In family 1, two brothers were affected by idiopathic NOA. In family 2, the proband was diagnosed with idiopathic NOA, and his elder sister suffered from infertility. Whole-exome sequencing (WES) was conducted in the two patients in family 1, the proband in family 2 and 362 additional sporadic patients with idiopathic NOA. Sanger sequencing was used to verify the WES results. Periodic acid–Schiff (PAS), immunohistochemistry (IHC) and meiotic chromosomal spread analyses were carried out to evaluate the stage of spermatogenesis arrested in the affected cases.ResultsWe identified compound heterozygous loss of function (LoF) variants of SHOC1 (c.C1582T:p.R528X and c.231_232del:p.L78Sfs*9, respectively) in both affected cases with NOA from family 1. In family 2, homozygous LoF variant in SHOC1 (c.1194delA:p.L400Cfs*7) was identified in the siblings with infertility. PAS, IHC and meiotic chromosomal spread analyses demonstrated that the spermatogenesis was arrested at zygotene stage in the three patients with NOA. Consistent with the autosomal recessive mode of inheritance, all of these SHOC1 variants were inherited from heterozygous parental carriers. Intriguingly, WES of 362 sporadic NOA cases revealed one additional NOA case with a bi-allelic SHOC1 LoF variant (c.1464delT:p.D489Tfs*13).ConclusionTo the best of our knowledge, this is the first report identifying SHOC1 as the causative gene for human NOA. Furthermore, our study showed an autosomal recessive mode of inheritance in the NOA caused by SHOC1 deficiency.


Author(s):  
Gert R Dohle

Surgical treatment of male infertility is indicated in men with obstructive azoospermia due to epididymal and vassal blockage, in infertile men with a varicocele and oligozoospermia, and to harvest spermatozoa for future intracytoplasmic sperm injection (ICSI). Testis biopsy may be performed in men with normal testis volume and normal gonadotrophins to confirm the diagnosis of obstructive azoospermia. Furthermore, testis biopsies are indicated in men with risk factors for testis cancer, such as infertility and ultrasonograhic abnormalities.Varicocele repair seems effective in case of an infertility duration of at least 2 years, oligozoospermia, and otherwise unexplained infertility in a couple. The advantages of surgery in these couples are a fair chance of spontaneous pregnancies at relative low cost and with less obstetric problems and birth defect compared to pregnancies from IVF procedures.


2021 ◽  
Author(s):  
Dongdong Tang ◽  
Mingrong Lv ◽  
Yang Gao ◽  
Huiru Cheng ◽  
Kuokuo Li ◽  
...  

Abstract Background Non-obstructive azoospermia (NOA) is the most severe form of male infertility. More than half of the NOA patients were idiopathic for their etiology, in whom it’s difficult to retrieve sperm despite the application of microsurgical testicular sperm extraction (microTESE). Therefore, we conducted to this study to identify the potential genetic factors responsible for NOA, and investigate the sperm retrieval rate of microTESE for the genetic defected NOA.Methods One NOA patient from a consanguineous family (F1-II-1) and fifty NOA patients from non-consanguineous families were included in the study. Semen analyses, chromosome karyotypes, screening of Y chromosome microdeletions, sex hormone testing, and subsequent testicular biopsy were performed to categorize NOA or obstructive azoospermia. Potentialgenetic variants were identified by whole exome sequencing (WES),and confirmed by Sanger sequencing in F1 II-1. The candidate genes were screened in the other fifty NOA patients. Further experiments including quantitative real time-polymerase chain reaction and western blotting were performed to verify the effects of gene variation on gene expression.Results Normal somatic karyotypes and Y chromosome microdeletions were examined in all patients. Hematoxylin and eosin staining (H&E) of the testicular tissues suggested meiotic arrest, and a novel homozygous HFM1 variant (c.3490C>T: p.Q1164X) was identified in F1 II-1. Furthermore, another homozygous HFM1 variant (c.3470G>A: p.C1157Y) was also verified in F2 II-1 from the fifty NOA patients. Significantly decreased expression levels of HFM1 mRNA and protein were observed in the testicular tissues of these two mutants compared with controls. MicroTESE was performed in these two patients, while no sperm were retrieved. Conclusions Our study identified two novel homozygous variants of HFM1 that are responsible for spermatogenic failure and NOA, even microTESE can not contribute to retrieve sperm in these patients.


2021 ◽  
Author(s):  
juan hua ◽  
Lan Guo ◽  
Yao Yao ◽  
Yangyang Wan ◽  
Wen Hu ◽  
...  

Abstract Teratozoospermia is a rare disease associated with male infertility. Unfortunately, approximately 30% of the genetic causes associated with teratozoospermia remain unknown. Several recurrent genetic mutations have been reported to be associated with globozoospermia, macrozoospermia and acephalic spermatozoa, whereas the genetic basis of tapered-head sperm is relatively less well-understood. In this study, whole-exome sequencing (WES) identified a homozygous WD repeat domain 12 (WDR12) (p.Ser162Ala/c.484T>G) variant in an infertile patient with tapered-head sperm from a consanguineous Chinese family. Bioinformatic analysis predicted this mutation to be a pathogenic variant. To further verify the effect of this variant, we analyzed WDR12 protein expression in the patient’s spermatozoa by western blot and found WDR12 to be significantly down-regulated. Also, we found that WDR12 expression is increased in pachytene spermatocytes, and intense staining was visible throughout the round spermatids in mouse testis. Based on our results, we concluded that a rare biallelic pathogenic missense variant (p.Ser162Ala/c.484T>G) in the WDR12 gene causes teratozoospermia. These results will provide novel insights into understanding the molecular mechanisms of male infertility and will help clinicians provide accurate diagnoses.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Dongdong Tang ◽  
Mingrong Lv ◽  
Yang Gao ◽  
Huiru Cheng ◽  
Kuokuo Li ◽  
...  

Abstract Background Non-obstructive azoospermia (NOA) is the most severe form of male infertility; more than half of the NOA patients are idiopathic. Although many NOA risk genes have been detected, the genetic factors for NOA in majority of the patients are unknown. In addition, it is difficult to retrieve sperm from these patients despite using the microsurgical testicular sperm extraction (microTESE) method. Therefore, we conducted this genetic study to identify the potential genetic factors responsible for NOA and investigate the sperm retrieval rate of microTESE for genetically deficient NOA patients. Methods Semen analyses, sex hormone testing, and testicular biopsy were performed to categorize the patients with NOA. The chromosome karyotypes and Y chromosome microdeletion analyses were used to exclude general genetic factors. Whole exome sequencing and Sanger sequencing were performed to identify potential genetic variants in 51 patients with NOA. Hematoxylin and eosin staining (H&E) and anti-phosphorylated H2AX were used to assess the histopathology of spermatogenesis. Quantitative real time-polymerase chain reaction, western blotting, and immunofluorescence were performed to verify the effects of gene variation on expression. Results We performed whole exome sequencing in 51 NOA patients and identified homozygous helicase for meiosis 1(HFM1) variants (NM_001017975: c.3490C > T: p.Q1164X; c.3470G > A: p.C1157Y) in two patients (3.9%, 2/51). Histopathology of the testis showed that spermatogenesis was completely blocked at metaphase in these two patients carrying the HFM1 homozygous variants. In comparison with unaffected controls, we found a significant reduction in the levels of HFM1 mRNA and protein expression in the testicular tissues from these two patients. The patients were also subjected to microTESE treatment, but the sperms could not be retrieved. Conclusions This study identified novel homozygous variants of HFM1 that are responsible for spermatogenic failure and NOA, and microTESE did not aid in retrieving sperms from these patients.


2021 ◽  
pp. 1-7
Author(s):  
Esra Arslan Ateş ◽  
Ayberk Turkyilmaz ◽  
Kenan Delil ◽  
Ceren Alavanda ◽  
Mehmet Ali Söylemez ◽  
...  

Polycystic kidney disease (PKD) is a life-threatening condition resulting in end-stage renal disease. Two major forms of PKD are defined according to the inheritance pattern. Autosomal dominant PKD (ADPKD) is characterized by renal cysts, where nearly half of the patients suffers from renal failure in the 7th decade of life. Autosomal recessive PKD (ARPKD) is a rarer and more severe form presenting in childhood. Whole-exome sequencing (WES) analyses was performed to investigate molecular causes of the disease in the fetus. In this study, we present 2 fetuses prenatally diagnosed with PKD in a consanguineous family. WES analysis of the second fetus revealed a homozygous variant (c.740+1G&#x3e;A) in <i>DNAJB11</i> which is related to ADPKD. This study reveals that <i>DNAJB11</i> biallelic mutations may cause an antenatal severe form of ARPKD and contributes to understanding the <i>DNAJB11</i>-related ADPKD phenotype. The possibility of ARPKD due to biallelic mutations in ADPKD genes should be considered in genetic counseling.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Shuai Lu ◽  
Yayun Gu ◽  
Yifei Wu ◽  
Shenmin Yang ◽  
Chenmeijie Li ◽  
...  

AbstractInner dynein arm (IDA), composed of a series of protein complex, is necessary to cilia and flagella bend formation and beating. Previous studies indicated that defects of IDA protein complex result in multiple morphological abnormalities of the sperm flagellum (MMAF) and male infertility. However, the genetic causes and molecular mechanisms in the IDAs need further exploration. Here we identified two loss-of-function variants of WDR63 in both MMAF and non-obstructive azoospermia (NOA) affected cohorts. WDR63 encodes an IDA-associated protein that is dominantly expressed in testis. We next generated Wdr63-knockout (Wdr63-KO) mice through the CRISPR-Cas9 technology. Remarkably, Wdr63-KO induced decreased sperm number, abnormal flagellar morphology and male infertility. In addition, transmission electron microscopy assay showed severely disorganized “9 + 2” axoneme and absent inner dynein arms in the spermatozoa from Wdr63-KO male mice. Mechanistically, we found that WDR63 interacted with WDR78 mainly via WD40-repeat domain and is necessary for IDA assembly. Furthermore, WDR63-associated male infertility in human and mice could be overcome by intracytoplasmic sperm injection (ICSI) treatment. In conclusion, the present study demonstrates that bi-allelic variants of WDR63 cause male infertility via abnormal inner dynein arms assembly and flagella formation and can be used as a genetic diagnostic indicator for infertility males.


2021 ◽  
Vol 10 (7) ◽  
pp. 1400
Author(s):  
Caroline Kang ◽  
Nahid Punjani ◽  
Peter N. Schlegel

Non-obstructive azoospermia (NOA), or lack of sperm in the ejaculate due to spermatogenic dysfunction, is the most severe form of infertility. Men with this form of infertility should be evaluated prior to treatment, as there are various underlying etiologies for NOA. While a significant proportion of NOA men have idiopathic spermatogenic dysfunction, known etiologies including genetic disorders, hormonal anomalies, structural abnormalities, chemotherapy or radiation treatment, infection and inflammation may substantively affect the prognosis for successful treatment. Despite the underlying etiology for NOA, most of these infertile men are candidates for surgical sperm retrieval and subsequent use in intracytoplasmic sperm injection (ICSI). In this review, we describe common etiologies of NOA and clinical outcomes following surgical sperm retrieval and ICSI.


Neurology ◽  
2018 ◽  
Vol 91 (18) ◽  
pp. e1690-e1694 ◽  
Author(s):  
Ulrich A. Schatz ◽  
Simone Weiss ◽  
Stephan Wenninger ◽  
Benedikt Schoser ◽  
Wolfgang H. Muss ◽  
...  

ObjectiveTo expand the clinical and genetic spectrum of nemaline myopathy 10 by a series of Austrian and German patients with a milder disease course and missense mutations in LMOD3.MethodsWe characterized the clinical features and the genetic status of 4 unrelated adolescent or adult patients with nemaline myopathy.ResultsThe 4 patients showed a relatively mild disease course. They all have survived into adulthood, 3 of 4 have remained ambulatory, and all showed marked facial weakness. Muscle biopsy specimens gave evidence of nemaline bodies. All patients were unrelated but originated from Austria (Tyrol and Upper Austria) and Southern Germany (Bavaria). All patients carried the missense variant c.1648C>T, p.(Leu550Phe) in the LMOD3 gene, either on both alleles or in trans with another missense variant (c.1004A>G, p.Gln335Arg). Both variants were not reported previously.ConclusionsIn 2014, a severe form of congenital nemaline myopathy caused by disrupting mutations in LMOD3 was identified and denoted as NEM10. Unlike the previously reported patients, who had a severe clinical picture with a substantial risk of early death, our patients showed a relatively mild disease course. As the missense variant c.1648C>T is located further downstream compared to all previously published LMOD3 mutations, it might be associated with higher protein expression compared to the reported loss-of-function mutations. The apparent clusters of 2 mild mutations in Germany and Austria in 4 unrelated families may be explained by a founder effect.


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