Biallelic mutations in PMFBP1 cause acephalic spermatozoa.

The majority of men with defects in spermatogenesis remain undiagnosed. Acephalic spermatozoa is one of the diseases causing primary infertility. However, the causes underlying over half of affected cases remain unclear. Here, we report by whole-exome sequencing the identification of homozygous and compound heterozygous truncating mutations in PMFBP1 of two unrelated individuals with acephalic spermatozoa. PMFBP1 was highly and specifically expressed in human and mouse testis. Furthermore, immunofluorescence staining in sperm from a normal control showed that PMFBP1 localizes to the head-flagella junction region, and the absence of PMFBP1 was confirmed in patients harboring PMFBP1 mutations. In addition, we generated Pmfbp1 knock-out (KO) mice, which we found recapitulate the acephalic sperm phenotype. Label-free quantitative proteomic analysis of testicular sperm from Pmfbp1 KO and control mice showed 124 and 35 proteins, respectively, increased or decreased in sperm from KO mice compared to that found in control mice. Gene ontology analysis indicates that the biological process of Golgi vesicle transport was the most highly enriched in differentially expressed proteins, indicating process defects related to Golgi complex function may disturb formation of the head-neck junction. Collectively, our data indicate that PMFBP1 is necessary for sperm morphology in both humans and mice, and that biallelic truncating mutations in PMFBP1 cause acephalic spermatozoa.

Patients with multiple morphological abnormalities of the sperm flagella harbouring CFAP44 or CFAP43 mutations have a good pregnancy outcome following intracytoplasmic sperm injection.

Multiple morphological abnormalities of the sperm flagella (MMAF) are a rare type of male infertility. Mutations in DNAH1, CFAP43 and CFAP44 are the main aetiology of the disorder. Previously, good intracytoplasmic sperm injection (ICSI) outcomes were reported for MMAF patients with DNAH1 mutations. However, the ICSI prognosis for MMAF patients with CFAP43 or CFAP44 mutations was not known. We designed a retrospective cohort study. Molecular genetic testing identified six MMAF patients with biallelic CFAP44 (CFAP44+ group) or CFAP43 mutations and 12 patients with homozygous or compound heterozygous DNAH1 mutations (DNAH1+ group). A control group consisted of age-matched, non-MMAF men. For MMAF patients carrying CFAP44 mutations, the recorded rates of fertilisation, transferable embryos, pregnancy and delivery after ICSI were 76.47%, 88.46%, 50.0% and 50.0% respectively. The fertilisation rate was significantly higher in the CFAP44+ group than in the DNAH1+ group (76.47% vs. 54.5%, p = 0.0196). There were no statistically significant differences in the rates of transferable embryos, implantation, clinical pregnancy and miscarriage between the CFAP44+ group and either the DNAH1+ group or the age-matched control group. Our results support a good ICSI prognosis for MMAF patients carrying CFAP44 or CFAP43 mutations.

[Familial fragile X syndrome: A pedigree analysis].

OBJECTIVE: To investigate the clinical (including reproductive) manifestations and genetic characteristics of familial fragile X syndrome (FXS). METHODS: We collected the clinical data about a case of familial FXS by inquiry, testicular ultrasonography, semen analysis, determination of sex hormone levels, and examinations of the peripheral blood karyotype and Y chromosome microdeletions. Using Southern blot hybridization, we measured the size of the CGG triple repeat sequence of the fragile X mental retardation-1 (FMR1) gene and determined its mutation type of the pedigree members with a genetic map of the FXS pedigree. RESULTS: Among the 34 members of 4 generations in the pedigree, 3 males and 1 female (11.76%) carried full mutation and 9 females (26.47%) premutation of the FMR1 gene. Two of the males with full FMR1 mutation, including the proband showed a larger testis volume (>30 ml) and a higher sperm concentration (>250 ×106/ml), with a mean sperm motility of 50.5%, a mean morphologically normal sperm rate of 17.5%, an average sperm nuclear DNA fragmentation index (DFI) of 18.5%, a low level of testosterone, normal karyotype in the peripheral blood, and integrity of the azoospermia factor (AZF) region in the Y chromosome. One of the second-generation females carrying FMR1 premutation was diagnosed with premature ovarian failure and another 3 with uterine myoma. CONCLUSIONS: Some of the FXS males in the pedigree may present macroorchidism and polyzoospermia but with normal semen parameters. In the intergenerational transmission, premutation might extend to full mutation, with even higher risks of transmission and extension of mutation in males, especially in those with >80 CGG triple repeat sequences. Therefore, it is recommended that the couples wishing for childbearing receive genetic testing, clinical guidance, and genetic counseling before pregnancy and, if necessary, prenatal diagnosis and preimplantation genetic diagnosis.

Non-chimerism and chimerism pseudo dicentric Y chromosome: two case reports about azoospermia and cytogenetic/molecular genetic analysis in the Chinese population.

OBJECTIVE: To report the cytogenetic and molecular genetic analysis of the first two cases of non-chimerism and chimerism karyotype in Chinese male patients who suffer from azoospermia, which may be caused by pseudo dicentric Y chromosomes. DESIGN: Case study. SETTING: Academic reproductive medicine center. PATIENTS: Two male patients with azoospermia, carrying pseudo dicentric Y chromosome. INTERVENTIONS: Review the records of inquiry, testicular biopsy, pathological examination, semen routine examination, endocrine evaluation, cytogenetic chromosomal analysis, and FISH detection of peripheral blood to evaluate Y chromosome deletion. MAIN OUTCOME MEASURES: To investigate the possible association among pseudo dicentric Y, chimeric status and azoospermia. RESULTS: Two patients were both diagnosed with azoospermia by a variety of andrology inspections. Further chromosomal analysis and FISH indicated their pseudo dicentric Y chromosome and different chimerism status. PCR confirmed simultaneous deletions of AZFb and AZFc regions in the Y chromosome of both patients. CONCLUSIONS: Pseudodicentric Y chromosome affecting the long arm may lead to a male phenotype by duplicating the sex-determining region of Y chromosome (SRY) fragment and chimeric status may further impact patient's hormone levels, which obstruct spermatogenesis. However, the deletion of the azoospermia factor (AZF) is likely the key factor that causes azoospermia.

[Current progress in cryopreservation of small numbers of sperm].

Human sperm cryopreservation is an increasingly mature technique in assisted reproduction. However, conventional sperm cryopreservation is not suitable for the cryopreservation of small numbers of sperm. The solution to the cryopreservation of small numbers of sperm may contribute a lot to the clinical treatment of asthenospermia, oligospermia and azoospermatism. Recently, many researchers focus on searching for appropriate carriers for the cryopreservation of small numbers of sperm. This article outlines the effects of current cryopreservation methods including empty zona pellucida, microdrops, other mocrocarriers, testicular tissue cryopreservation and testicular sperm and epididymal sperm refrigeration.

[Sperm selection in assisted reproductive technology: an update].

Sperm selection plays an important role in assisted reproductive technology. In recent years, sperm evaluation is not limited to the assessment of sperm motility and morphology, but involves more other sperm characteristics such as sperm ultrastructure, DNA integrity, apoptosis and membrane. Assessment based on these characteristics is becoming the aim of sperm selection. This article gives an overview on several newly developed techniques for sperm selection according to different technical principles, such as electrophoretic separation, zeta potential, HA binding, Annexin V binding, intracytoplasmic morphologically selected sperm injection (IMSI) and microfluidic sperm sorter, which have all been applied to IVF or ICSI with the exception of microfluidic sperm sorter. It also introduces the advantages, disadvantages and application effects of these techniques.

[Ring 22 chromosome syndrome induced azoospermia: a case report and literature review].

OBJECTIVE: To investigate the clinical phenotype and genetic characteristics of an azoospermia patient with ring 22 chromosome syndrome. METHODS: We analyzed the clinical data of an azoospermia patient with ring 22 chromosome syndrome and reviewed relevant literature. RESULTS: The patient was a short 29-year-old male, with bilateral testes small in size and soft in texture. Seminal examination indicated azoospermia. Chromosome analysis showed the karyotype of the patient to be 46, XY, r (22) (p11, q25). The level of testosterone was low, and the testicular tissue was brittle and easy to break. Pathological microscopy revealed reduced number of Sertoli cells and germ cells in the seminiferous tubules and thinner layers of cells. All the germ cells were spermatogonia. Neither spermatocytes nor sperm cells were found, which suggested complete spermatogenic failure. Mild interstitial fibrosis was visible in part of the seminiferous tubule walls. CONCLUSION: Patients with ring 22 chromosome syndrome usually represent normal clinical phenotypes. However, this kind of genetic abnormality often induces severe testicular damage and spermatogenic arrest, which may result in azoospermia.

[Multiplex ligation-dependent probe amplification for detecting AZF microdeletions on the Y chromosome in infertile men with azoospermia or severe oligozoospermia].

OBJECTIVE: To investigate the possibility of applying multiplex ligation-dependent probe amplification (MLPA) to the detection of azoospermia factor (AZF) microdeletion on the Y chromosome in infertile men with azoospermia or severe oligozoospermia. METHODS: DNA samples were obtained from 147 azoospermia or severe oligozoospermia patients and 154 normal controls. After denatured at 95 degrees C, the samples were hybridized to the specific probes designed for the AZF region. With the ligase, the hybrid products were amplified by a pair of universal primers labeled with FAM fluorescence, and then separated by capillary electrophoresis for data analysis. Meanwhile all the samples were subjected to multiplex-PCR (mPCR) analysis for sequence-tagged sites (STS) in the AZF region. RESULTS: STS deletion was detected in 22 (15.0%) of the 147 patients but not in the normal controls. By MLPA, 40 (27.2%) of the patients were found with specific probe omission in the AZF region, as compared with 20 cases in the control group. CONCLUSION: Compared with mPCR, MLPA has a better sensitivity in detecting AZF microdeletions, and it provides more precise genetic information on the AZF regions, which may contribute to in-depth exploration into the etiological mechanism of impaired spermatogenesis.

Biallelic mutations in spermatogenesis and centriole-associated 1 like (SPATC1L) cause acephalic spermatozoa syndrome and male infertility.

Acephalic spermatozoa syndrome is a rare type of teratozoospermia that severely impairs the reproductive ability of male patients, and genetic defects have been recognized as the main cause of acephalic spermatozoa syndrome. Spermatogenesis and centriole-associated 1 like (SPATC1L) is indispensable for maintaining the integrity of sperm head-to-tail connections in mice, but its roles in human sperm and early embryonic development remain largely unknown. Herein, we conducted whole-exome sequencing (WES) of 22 infertile men with acephalic spermatozoa syndrome. An in silico analysis of the candidate variants was conducted, and WES data analysis was performed using another cohort consisting of 34 patients with acephalic spermatozoa syndrome and 25 control subjects with proven fertility. We identified biallelic mutations in SPATC1L (c.910C>T:p.Arg304Cys and c.994G>T:p.Glu332X) from a patient whose sperm displayed complete acephalia. Both SPATC1L variants are rare and deleterious. SPATC1L is mainly expressed at the head-tail junction of elongating spermatids. Plasmids containing pathogenic variants decreased the level of SPATC1L in vitro. Moreover, none of the patient's four attempts at intracytoplasmic sperm injection (ICSI) resulted in a transplantable embryo, which suggests that SPATC1L defects might affect early embryonic development. In conclusion, this study provides the first identification of SPATC1L as a novel gene for human acephalic spermatozoa syndrome. Furthermore, WES might be applied for patients with acephalic spermatozoa syndrome who exhibit reiterative ICSI failures.

[Globozoospermia syndrome: an update].

Globozoospermia syndrome is a rare teratozoospermia, with an incidence of less than 0.1%. It is characterized by round sperm head, absence of acrosome, and messy sperm body and tail, but without other special clinical features. The absence of acrosome could reduce the activation ability of oocytes, and consequently decrease their fertilization ability. The assisted reproductive technique remains the only means for such patients to produce offspring. The pathogenesis of globozoospermia syndrome is not yet clear, though it is found to be related with 4 genes in the mouse and 1 on the human autosome. This article gives an overview on the clinical features, pathogenesis and genetics of globozoospermia syndrome, as well as the fertilizability and reproductivity of such patients.

[Congenital adrenal hyperplasia complicated by testicular adrenal rest tumors: one-case clinical analysis].

OBJECTIVE: To investigate the early diagnosis and treatment of congenital adrenal hyperplasia (CAH) complicated by testicular adrenal rest tumors (TART). METHODS: We retrospectively analyzed the clinical data of 1 case of late-onset CAH complicated by TART diagnosed and treated in Xiamen Women and Children Health Care Hospital. RESULTS: The patient was a 15 years old boy, short statured and dark skinned, with skin pigmentation in the gum and external genital, secondary sex characteristics of the adult and irregular tubercles palpable in the bilateral testes. Laboratory examinations showed obviously increased levels of ACTH, 17-KS, DHEA-S and progesterone and evidently decreased levels of FSH, LH and CO. The low-dose dexamethasone suppression test reduced ACTH and DHEA-S to normal. Imaging examinations revealed soft tissue density in the bilateral adrenal glands, especially on the right, and irregularly increased volume of the bilateral testes, particularly on the left, with heterogeneous signals and septas and surrounded by the fluid signals. Histopathological examinations showed the eosinophilic cytoplasm to be polygon- or round-shaped, interstitium-like cells arranged in line, and lipopigment in the endochylema. Immunohistochemical results were negative for testicular interstitial cell tumor. The clinical signs of the patient were improved after 3 months of dexamethasone treatment, the hyperplastic nodules in the left testis decreased obviously and those in the right testis disappeared after 6 months, and the hyperplastic nodules in the adrenal glands vanished after 9 months. CONCLUSION: Based on the clinical manifestations and the results of auxiliary examinations, this case was diagnosed as late-onset CAH complicated by TART, which was attributed to the continued surge of ACTH induced by corticoadrenal insufficiency. Sufficient dexamethasone treatment could make the TART decrease or disappear and the CAH vanish; it could also improve the clinical symptoms and bring the laboratory results to normal.

[Evolution and mutation of human Y chromosome and their relationship with male infertility].

The Y chromosome evolves from euchromosome and accumulates a variety of male-specific genes, including SRY and many others that are related with spermatogenesis. The Y chromosome is distinguished from euchromosome by its characteristics of multiple copies of gene, multiple DNA sequences and high polymorphism. A lot of gene rearrangements occur during its evolution due to the specific gene structure in the Y chromosome. It has been discovered that one subset of such gene rearrangements induces Y-chromosome microdeletions that are involved in male infertility. Spermatogenesis is actually controlled by a network of genes, which may be located on the Y chromosome, euchromosomes or even the X chromosome. Further studies on the genomics and genes in the Y chromosome between sex chromosomes and/or between sex chromosome and euchromosomes will helps us to gain deeper insights into the molecular mechanism of male infertility.

Novel IFT140 variants cause spermatogenic dysfunction in humans.

BACKGROUND: The intraflagellar transport protein 140 homolog (IFT140) is involved in the process of intraflagellar transport (IFT), a process that is essential for the formation and maintenance of most eukaryotic cilia and flagella. Variants IFT140 have been reported to account for ciliopathy but association with male fertility has never been described in humans. Here we report the identification of two novel variants of IFT140 which caused spermatogenic dysfunction and male infertility. METHODS: Whole-exome sequencing was performed in a 27-year-old infertile man presented with severe oligozoospermia, asthenozoospermia, and teratozoospermia (OAT) without other physical abnormality. Sanger sequencing was used to verify gene variants in the patient, his healthy brother, and their parents. Morphology and protein expression in the patient's sperm were examined by transmission electron microscopy (TEM) and immunofluorescence staining. Function of gene variants was predicted by online databases. RESULTS: Compound heterozygous variants of IFT140: exon16: c.1837G > A: p.Asp613Asn and exon31: c.4247G > A: p.Ser1416Asn were identified in the patient, both of which showed autosomal recessive inheritance in his family, and had extremely low allele frequency in the population. Morphological abnormalities of the head, nucleus, and tails and the absence of IFT140 from the neck and mid-piece of the patient's spermatozoa were observed. Mutation Taster database predicted a high probability of damage-causing by both variations. CONCLUSION: This study for the first time reported IFT140 variants that cause infertility in humans.

Novel Mutations in CFAP44 and CFAP43 Cause Multiple Morphological Abnormalities of the Sperm Flagella (MMAF).

Multiple morphological abnormalities of the sperm flagella (MMAF) is a rare disease that causes primary infertility. However, the genetic causes for approximately half of MMAF cases are unknown. Whole exome sequencing analysis of the 27 patients with MMAF identified several CFAP44 mutations (3 homozygous: c.2935_2944del: p.D979*, c.T1769A: p.L590Q, c.2005_2006del: p.M669Vfs*13; and putative compound heterozygous: c.G3262A: p.G1088S and c.C1718A: p.P573H.) and CFAP43 acceptor splice-site deletion (c.3661-2A>-) mutations in 5 and 1 patients, respectively. Real-time quantitative polymerase chain reaction assays also demonstrated that CFAP44 expression was very weak in patient (P)1 and P3, and CFAP43 expression was lower in P6 than in the control. Immunofluorescence analysis of CFAP43 showed lower CFAP43 protein expression levels in P6 than in the normal control. This study demonstrated that biallelic mutations in CFAP44 and CFAP43 cause MMAF. These results provide researchers with a new insight to understand the genetic etiology of MMAF and to identify new loci for genetic counselling of MMAF.

Genetic contribution of SUN5 mutations to acephalic spermatozoa in Fujian China.

Acephalic spermatozoa is an extremely rare disease associated with primary infertility. A recent study showed that genetic alterations in the SUN5 gene lead to this disease, and SUN5 mutations could explain the disease in about half of the patients. Therefore, in the present study, to re-visit the genetic contribution of SUN5 mutations to acephalic spermatozoa, we recruited 15 unrelated affected individuals and screened the SUN5 gene for mutations by whole-exome sequencing (WES) and Sanger sequencing. Five of the 15 (33.33%) subjects were found to carry the same homozygous mutation in the SUN5 gene c.381delA (p.V128Sfs*7). Neither homozygous nor compound heterozygous mutations in SUN5 were found in the other 10 patients. The c.381delA mutation resulted in the truncation of the SUN5 protein and decreased the expression and altered the distribution of the outer dense fiber 1 (ODF1) protein. Thus, in our study SUN5 mutations accounted for only one-third of the patients in our cohort, which is lower than the percentage reported previously. Thus, our study suggests that the contribution of SUN5 mutations to acephalic spermatozoa might not be as high as described previously. These results will help in the genetic counseling of patients with acephalic spermatozoa.

Sperm-egg fusion disorder in a Chinese male patient was associated with a rare ADAM20 variant.

We report here a 28-year-old male with infertility. No abnormality was found in his semen examination. The couple achieved a successful pregnancy under the help of intracytoplasmic sperm injection during which we found that sperm could enter the zona pellucida, but could not fuse with the egg within the short insemination period. We then performed whole-exome sequencing technology on this patient and found a rare variant (c.641A>C:p.D214A) in ADAM20, which encoded a disintegrin and metalloprotease 20 protein. To further verify the pathogenicity of this variant, we analyzed ADAM20 protein expression in spermatozoa by immunostaining analysis, which showed a mis-localization of ADAM20 in the patient's spermatozoa. Therefore, we concluded that mutation in ADAM20 may be associated with sperm-egg fusion disorder in this patient.

A novel mutation in HAUS7 results in severe oligozoospermia in two brothers.

Severe oligozoospermia (SO) is a common disease resulting in male infertility; however, its pathophysiology remains unclear. Here, we report two brothers with SO. Whole-exome sequencing (WES) identified a hemizygous variant in HAUS7 (c.G386T:p.G129V), an X-linked gene. HAUS7 has been reported to play a role in the meiotic maturation and chromosome alignment of germ cells. The two patients inherited this variant from their mother, and this variant was considered to be a highly pathogenic mutation by in silico analysis. Moreover, in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) was carried out in both the proband's wife and the brother's wife, but they failed to become pregnant after the embryo transfers. Therefore, this novel mutation in HAUS7 gene may be associated with severe oligozoospermia.

Two cases of complex balanced autosomal translocations associated with severe oligozoospermia.

Complex balanced autosomal translocation is rare and can lead to impaired spermatogenesis in males; however, its effects on oligozoospermia have rarely been reported. We report here two cases of rare complex balanced translocation in men with infertility. The karyotype of the first case was 46,XY,der(1)t(1;12)(p22;p11.2)ins(9;1)(p24;q25q23),der(9)ins(9;1),der(12)t(1;12)·ish der(1)t(1;12)(RP11-636B1+;RP11-659D23+)ins(9;1)(RP11-118P13+),der(9)ins(9;1),der(12)t(1;12). And the patient showed severe oligozoospermia with adult schizophrenia without other abnormalities. The karyotype of the second patient was 46,XY,der(5)t(5;11)(q14;p11.2),der(11)t(11;18)(p11.2;q11.2),der(18)t(5,18)(q14;p11.3)add(18)(q11.2?)·ish der(5)t(5;11)(RP11-846K3+,RP11-89B9+),der(11)t(11;18)(RP11-89B9-,RP11-170L12+,RP11-469N6+),der(18)t(5;18)(RP11-125L2+,RP11-29M13+)add(18)(q11.2?), and the patient displayed severe oligozoospermia without other abnormalities. The two cases were verified by fluorescent in situ hybridization, and no abnormalities were found by genome-wide copy number variation analysis. To our knowledge, these two cases of complex autosomal karyotypes have not been reported previously. Although rare, these cases suggest that complex balanced translocations may be important causes of oligozoospermia. We speculate that the balanced translocation hinders germ cell meiosis and causes impaired spermatogenesis. Accordingly, the two reported patients have very low probabilities of giving birth to a normal child; therefore, we suggest choosing donor semen or adopting a child.

Identification of a novel mutation in FGFR1 gene in patients with Kallmann syndrome by high throughput sequencing.

Kallmann syndrome (KS) is a rare clinical and genetic heterogeneity disease, which is familial or sporadic. KS is known to have three patterns of inheritance: X linked recessive inheritance, autosomal dominant inheritance and rare autosomal recessive inheritance. Here, we report a sibling pedigree with autosomal dominant inheritance of KS, and we identified a novel heterozygous frameshift mutation c.299_300insCCGCAGACTCCGGCCTCTATGC (p.C101Rfs*17) in FGFR1 gene using whole-exome sequencing (WES). The mutation and affection status were cosegregated. The mutation is not present in the dbSNP, 1000 Genome, ExAC, and gnomAD databases. The discovery of this new mutation in the FGFR1 gene enriches the spectrum of FGFR1 mutations in patients with KS. ABBREVIATIONS: FGFR1: fibroblast growth factor receptor 1; HH: hypogonadotropic hypogonadism; KS: Kallmann syndrome; MRI: magnetic resonance imaging; WES: whole-exome sequencing.

TDRD6 is associated with oligoasthenoteratozoospermia by sequencing the patient from a consanguineous family.

Oligoasthenoteratozoospermia (OAT) is characterized as low sperm count, decreased sperm motility and structural abnormalities of the sperm head in the same patient. However, very few studies reported the genetic alterations associated with OAT. Here we report a 38-year-old patient with OAT from a consanguineous family, with 2-6 million/mL sperm density, 2.1-3.8% normal sperm morphology and immotile sperm. Whole-exome sequencing (WES) identified homozygous variant c.1259A>G:p.Y420C in the TDRD6 gene. TDRD6 is a testis-specific expressed protein that was localized to the chromatoid bodies in germ cells and played an important role in the nonsense-mediated decay pathway. This rare variant co-segregated with the OAT phenotype in this family. Bioinformatic analysis also suggested the variant a pathogenic mutation. Two intracytoplasmic sperm injection (ICSI) cycles were carried out in the patient's wife, but she did not become pregnant after embryo transfer. So the mutations in TDRD6 may be associated with human male infertility and early embryonic lethality.