Comparative Functional Analysis in vitro of 2 COL4A5 Splicing Mutations at the Same Site in 2 Unrelated Alport Syndrome Chinese Families.

X-linked Alport syndrome (XLAS) is a common hereditary nephropathy caused by COL4A5 gene mutations. To date, many splice site mutations have been described but few have been functionally analyzed to verify the exact splicing effects that contribute to disease pathogenesis. Here, we accidentally discovered 2 COL4A5 gene splicing mutations affecting the same residue (c.2917+1G>A and c.2917+1G>C) in 2 unrelated Chinese families. In vitro minigene assays showed that the 2 mutations produced 3 transcripts in H293T cells: one with a 96-bp deletion in exon 33, one with exon 33 skipping, and one with exon 33-34 skipping. However, fragment analysis results showed that the main splicing effects of the 2 mutations were different, the c.2917+1G>A mutation mainly activated a cryptic donor splice site in exon 33 and resulted in the deletion of 96 bp in exon 33, while the c.2917+1G>C mutation mainly caused exon 33 skipping. Our findings indicate that different nucleotide substitutions at the same residue can cause different splicing effects, which may contribute to the variable phenotype of Alport syndrome.

The COL4A3 and COL4A4 Digenic Mutations in cis Result in Benign Familial Hematuria in a Large Chinese Family.

Mutations in the COL4A5 gene result in X-linked Alport syndrome, homozygous or compound heterozygous mutations in COL4A3 or COL4A4 are responsible for autosomal recessive Alport syndrome, and heterozygous mutations in COL4A3 or COL4A4 cause autosomal dominant Alport syndrome or benign familial hematuria. Recently, the existence of a digenic inheritance in Alport syndrome has been demonstrated. We here report heterozygous COL4A3 and COL4A4 digenic mutations in cis responsible for benign familial hematuria. Using bioinformatics analyses and pedigree verification, we showed that COL4A4 c.1471C>T and COL4A3 c.3418 + 1G>T variants in cis are pathogenic and co-segregate with the benign familial hematuria. This result suggests that COL4A3 and COL4A4 digenic mutations in cis mimicking an autosomal dominant inheritance should be considered as a novel inheritance pattern of benign familial hematuria, although the disease-causing mechanism remains unknown.

Three Novel Heterozygous COL4A4 Mutations Result in Three Different Collagen Type IV Kidney Disease Phenotypes.

Thin basement membrane nephropathy (TBMN), autosomal dominant Alport syndrome (ADAS), and focal segmental glomerulosclerosis (FSGS) are kidney diseases that differ in clinical diagnosis, treatment, and prognosis. Nevertheless, they may result from the same causative genes. Here, we report 3 COL4A4 heterozygous mutations (p.Gly208Arg, p.Ser513Glufs*2, and p.Met1617Cysfs*39) that lead to 3 different collagen type IV kidney disease phenotypes, manifesting as TBMN, ADAS, and FSGS. Using bioinformatics analyses and pedigree verification, we show that these novel variants are pathogenetic and cosegregate with TBMN, ADAS, and FSGS. Furthermore, we found that the collagen type IV-associated kidney disease phenotypes are heterogeneous, with overlapping pathology and genetic mutations. We propose that COL4A4-associated TBMN, ADAS, and FSGS should be considered as collagen type IV kidney disease subtypes that represent different phases of disease progression.

A novel COL4A1 gene mutation results in autosomal dominant non-syndromic congenital cataract in a Chinese family.

BACKGROUND: Almost one-third of congenital cataracts are primarily autosomal dominant disorders, which are also called autosomal dominant congenital cataract, resulting in blindness and clouding of the lens. The purpose of this study was to identify the disease-causing mutation in a Chinese family affected by bilateral, autosomal dominant congenital cataract. METHODS: The detection of candidate gene mutation and the linkage analysis of microsatellite markers were performed for the known candidate genes. Molecular mapping and cloning of candidate genes were used in all affected family members to screen for potential genetic mutations and the mutation was confirmed by single enzyme digestion. RESULTS: The proband was diagnosed with isolated, congenital cataract without the typical clinical manifestations of cataract, which include diabetes, porencephaly, sporadic intracerebral hemorrhage, and glomerulopathy. A novel mutation, c.2345 G > C (Gly782Ala), in exon 31 of the collagen type IV αlpha1 (COL4A1) gene, which encodes the collagen alpha-1(IV) chain, was found to be associated with autosomal dominant congenital cataract in a Chinese family. This mutation was not found in unaffected family members or in 200 unrelated controls. Sequence analysis confirmed that the Gly782 amino acid residue is highly conserved. CONCLUSIONS: The novel mutation (c.2345 G > C) of the COL4A1 gene is the first report of a non-syndromic, autosomal dominant congenital cataract, thereby highlighting the important role of type IV collagen in the physiological and optical properties of the lens.

Polymorphisms in estrogen receptors predict the risk of male infertility: a meta-analysis.

BACKGROUND: Estrogen receptors play an important role in mediating estrogen action on target tissues, and the estrogen is relevant to male infertility. Single nucleotide polymorphisms (SNPs) in estrogen receptors may be associated with the risk of male infertility. A variety of case control studies have been published evaluating this association. However, the accumulated studies have shown inconsistent conclusions. METHODS: To further determine the potential association between the four common SNPs (rs2234693, rs9340799, rs1256049 and rs4986938) in estrogen receptors gene and male infertility, this meta-analysis was performed according to the 10 published case control studies. The odds ratio (OR) and 95% confidence interval (CI) were used to evaluate the strength of the associations. RESULTS: It was revealed that the sub-group analysis by the ethnicity, for the rs2234693, a significant association in the comparison of CC vs. TT (OR = 0.61, 95% CI: 0.40-0.93), CT vs. TT (OR = 0.67, 95% CI: 0.49-0.93) and CC + CT vs. TT (OR = 0.66, 95% CI: 0.49-0.89) in the Asian population with male infertility. For rs9340799 polymorphism, increased risks were observed for the comparison of AA vs. GG (OR = 1.75, 95% CI: 1.15-2.68) and AA vs. GA + GG (OR = 1.38, 95% CI: 1.02-1.88). For rs1256049 polymorphism, the comparison of the GA vs. GG (OR = 1.52, 95% CI: 1.00-2.31) and AA + GA vs. GG (OR = 1.74, 95% CI: 1.03-2.94), also increased risks present in Asian and Caucasian population, respectively. CONCLUSIONS: The rs2234693C allele was associated with the decreased risk for male infertility; however, the rs9340799AA genotype and the rs1256049GA genotype were associated with an increased risk for male infertility.

Clinical, molecular and cytogenetic analysis of 46, XX testicular disorder of sex development with SRY-positive.

BACKGROUND: To review the possible mechanisms proposed to explain the etiology of 46, XX sex reversal by investigating the clinical characteristics and their relationships with chromosomal karyotype and the SRY(sex-determining region Y)gene. METHODS: Five untreated 46, XX patients with SRY-positive were referred for infertility. Clinical data were collected, and Karyotype analysis of G-banding in lymphocytes and Fluorescence in situ hybridization (FISH) were performed. Genomic DNA from peripheral blood of the patients using QIAamp DNA Blood Kits was extracted. The three discrete regions, AZFa, AZFb and AZFc, located on the long arm of the Y chromosome, were performed by multiplex PCRs(Polymerase Chain Reaction) amplification. The set of PCR primers for the diagnosis of microdeletion of the AZFa, AZFb and AZFc region included: sY84, sY86, sY127, sY134, sY254, sY255, SRY and ZFX/ZFY. RESULTS: Our five patients had a lower body height. Physical examination revealed that their testes were small in volume, soft in texture and normal penis. Semen analyses showed azoospermia. All patients had a higher follicle-stimulating hormone(FSH), Luteinizing Hormone(LH) level, lower free testosterone, testosterone level and normal Estradiol, Prolactin level. Karyotype analysis of all patients confirmed 46, XX karyotype, and FISH analysis showed that SRY gene were positive and translocated to Xp. Molecular analysis revealed that the SRY gene were present, and the AZFa, AZFb and AZFc region were absent. CONCLUSIONS: This study adds cases on the five new 46, XX male individuals with SRY-positive and further verifies the view that the presence of SRY gene and the absence of major regions in Y chromosome should lead to the expectance of a completely masculinised phenotype, abnormal hormone levels and infertility.

46,XX testicular disorder of sexual development with SRY-negative caused by some unidentified mechanisms: a case report and review of the literature.

BACKGROUND: 46,XX testicular disorder of sex development is a rare genetic syndrome, characterized by a complete or partial mismatch between genetic sex and phenotypic sex, which results in infertility because of the absence of the azoospermia factor region in the long arm of Y chromosome. CASE PRESENTATION: We report a case of a 14-year-old male with microorchidism and mild bilateral gynecomastia who referred to our hospital because of abnormal gender characteristics. The patient was treated for congenital scrotal type hypospadias at the age of 4 years. Semen analysis indicated azoospermia by centrifugation of ejaculate. Levels of follicle-stimulating hormone and luteinizing hormone were elevated, while that of testosterone was low and those of estradiol and prolactin were normal. The results of gonadal biopsy showed hyalinization of the seminiferous tubules, but there was no evidence of spermatogenic cells. Karyotype analysis of the patient confirmed 46,XX karyotype and fluorescent in situ hybridization analysis of the sex-determining region Y (SRY) gene was negative. Molecular analysis revealed that the SRY gene and the AZFa, AZFb and AZFc regions were absent. No mutation was detected in the coding region and exon/intron boundaries of the RSPO1, DAX1, SOX9, SOX3, SOX10, ROCK1, and DMRT genes, and no copy number variation in the whole genome sequence was found. CONCLUSION: This study adds a new case of SRY-negative 46,XX testicular disorder of sex development and further verifies the view that the absence of major regions from the Y chromosome leads to an incomplete masculine phenotype, abnormal hormone levels and infertility. To date, the mechanisms for induction of testicular tissue in 46,XX SRY-negative patients remain unknown, although other genetic or environmental factors play a significant role in the regulation of sex determination and differentiation.

A novel P20R mutation in the alpha-B crystallin gene causes autosomal dominant congenital posterior polar cataracts in a Chinese family.

BACKGROUND: To identify the genetic defects and investigate the possible mechanism of cataract genesis in a five-generation family with autosomal dominant congenital posterior polar cataracts. METHODS: Clinical data were collected, and the lens phenotypes of the affected members in this family were recorded by slit lamp photography. Genomic DNA was isolated from peripheral blood using QIAamp DNA Blood Mini Kits. Twenty-three mutational hot spots associated with autosomal dominant congenital posterior polar cataracts were screened by PCR-based DNA sequencing. Properties and structural models of wild-type and mutant alpha-B (αB)-crystallin (CRYAB) were generated and analyzed using SWISS-MODEL. RESULTS: All affected individuals in this family started to exhibit poor vision at the age of 8-10 years. The lens opacity consisted of a single, well-defined plaque, 0.5-3 mm in diameter, which was confined to the posterior pole of the lens. DNA sequencing analysis of the affected members showed a novel, heterozygous missense mutation c.59C > G (P20R) in exon 1 of the CRYAB gene. This mutation was not found in 10 unaffected family members, or in 200 unaffected and unrelated individuals, thereby excluding the possibility that it is a rare polymorphism. Data generated using the ProtScale and PyMOL programs revealed that the mutation altered the stability and solubility of the αB-crystallin protein. CONCLUSIONS: This study reported a novel c.59C > G (P20R) missense mutation in CRYAB in a five-generation Chinese family with posterior polar cataract.

[Detection of DPY19L2 gene mutation in a globozoospermia patient].

OBJECTIVE: Globozoospermia is mostly associated with homozygous deletion of the DPY19L2 gene. This study aimed to investigate the DPY19L2 gene mutation in a globozoospermia patient. METHODS: We observed the sperm histomorphology of a patient with globozoospermia using Wright-Giemsa's staining and transmission electron microscopy, detected the mutation of the DPY19L2 gene by PCR amplification and DNA sequencing, and compared the findings with the sequences issued in the Genbank. RESULTS: Wright-Giemsa's staining showed that all the spermatozoa were round-headed and lacked the acrosome, with the head nucleus darkly, fully and densely stained. Transmission electron microscopy revealed larger round sperm heads, with an even layer of unit membrane surrounding the nuclei and dispersed cytoplasmic vacuoles but no acrosomal structure. No DPY19L2 gene mutation was found by PCR amplification and DNA sequencing. CONCLUSION: No homozygous mutation of the DPY19L2 gene was found in the globozoospermia patient, and therefore some other disease-causing genes might be involved.

A mouse model for X-linked Alport syndrome induced by Del-ATGG in the Col4a5 gene.

Alport syndrome (AS) is an inherited glomerular basement membrane (GBM) disease leading to end-stage renal disease (ESRD). X-linked AS (XLAS) is caused by pathogenic variants in the COL4A5 gene. Many pathogenic variants causing AS have been detected, but the genetic modifications and pathological alterations leading to ESRD have not been fully characterized. In this study, a novel frameshift variant c.980_983del ATGG in the exon 17 of the COL4A5 gene detected in a patient with XLAS was introduced into a mouse model in by CRISPR/Cas9 system. Through biochemical urinalysis, histopathology, immunofluorescence, and transmission electron microscopy (TEM) detection, the clinical manifestations and pathological alterations of Del-ATGG mice were characterized. From 16 weeks of age, obvious proteinuria was observed and TEM showed typical alterations of XLAS. The pathological changes included glomerular atrophy, increased monocytes in renal interstitial, and the absence of type IV collagen α5. The expression of Col4a5 was significantly decreased in Del-ATGG mouse model. Transcriptomic analysis showed that differentially expressed genes (DEGs) accounted for 17.45% (4,188/24003) of all genes. GO terms indicated that the functions of identified DEGs were associated with cell adhesion, migration, and proliferation, while KEGG terms found enhanced the degradation of ECM, amino acid metabolism, helper T-cell differentiation, various receptor interactions, and several important pathways such as chemokine signaling pathway, NF-kappa B signaling pathway, JAK-STAT signaling pathway. In conclusion, a mouse model with a frameshift variant in the Col4a5 gene has been generated to demonstrate the biochemical, histological, and pathogenic alterations related to AS. Further gene expression profiling and transcriptomic analysis revealed DEGs and enriched pathways potentially related to the disease progression of AS. This Del-ATGG mouse model could be used to further define the genetic modifiers and potential therapeutic targets for XLAS treatment.

[Cigarette smoking affects sperm plasma membrane integrity].

OBJECTIVE: To detect sperm plasma membrane integrity (PMI) of cigarette smoking infertile males using SYBR-14/ PI fluorescent staining and flow cytometry and investigate its clinical significance. METHODS: We collected semen samples from 132 cigarette smoking infertile men and 70 normal fertile controls, the former divided into a heavy-smoker group (> 20 cigarettes a day, n = 68) and a light-smoker group (< or = 20 cigarettes a day, n = 64). We performed computer-assisted semen analysis of the semen samples, and determined sperm PMI by flow cytometry after rinsing with PBS and staining by SYBR-14/PI, the sperm with normal PMI indicated as the percentage of those emitting green fluorescence (SYBR-14+/PI- %), dead sperm as the percentage of those emitting red (SYBR-14-/PI+), and moribund sperm as the percentage of those emitting both green and red (SYBR-14+/PI+). RESULTS: Both the heavy- and light-smoker groups showed significant differences in SYBR-14-/PI+ % and SYBR-14+/PI- % from the normal controls (P < 0.01 or P < 0.05). SYBR-14+/PI- % was remarkably lower, while SYBR-14-/PI+ % markedly higher in the heavy-smoker than in the light-smoker group (P < 0.05). There was a significant correlation between SYBR-14+/PI- % and sperm motility (r = 0.938, P = 0.000). CONCLUSION: SYBR-14/PI fluorescent staining and flow cytometry analysis could quickly and exactly detect sperm PMI. Cigarette smoking reduces sperm PMI and consequently sperm motility, which might be an important factor of male infertility.

[Protective effect of L-carnitine combined with sildenafil on the reproductive endocrine function of diabetic male rats].

OBJECTIVE: To investigate the protective effect of L-carnitine (LC) combined with sildenafil on the reproductive endocrine function of male rats with diabetes mellitus (DM). METHODS: A total of 40 male SD rats were randomly divided into five groups, group A taken as normal controls, and groups B, C, D and E made into DM models by injection of streptozotocin at 65 mg/kg. Then the rats in groups A and B were treated with normal saline, C with sildenafil at 5 mg per kg per d, D with LC at 300 mg per kg per d, and E with sildenafil at 5 mg per kg per d plus LC at 300 mg per kg per d, all via gastric gavage for 6 weeks, followed by determination of the levels of testosterone (T), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in the serum of the rats. RESULTS: After 6 weeks of treatment, the T, FSH and LH levels were (25.25 +/- 2.67) nmol/L, (5.78 +/- 0.61) IU/L and (625.21 +/- 43.45) ng/L in group A, (9.63 +/- 1.71) nmol/L, (1.98 +/- 0.42) IU/L and (479.89 +/- 27.62) ng/L in group B, (18.98 +/- 3.07) nmol/L, (5.08 +/- 0.33) IU/L and (586.57 +/- 31.72) ng/L in group C, (16.18 +/- 2.65) nmol/L, (4.63 +/- 0.30) IU/L and (540.78 +/- 25.52) ng/L in group D, and (23.65 +/- 2.66) nmol/L, (5.59 +/- 0.48) IU/L and (621.53 +/- 36. 40) ng/L in group E. The three parameters were significantly lower in B than in the other four groups (P < 0.01), and so were they in C and D than in A and E (P < 0.05), but showed no significant differences either between C and D (P > 0. 05) or between A and E (P > 0.05). CONCLUSION: Six-week medication of either sildenafil or LC alone could increase the levels of T, FSH and LH in the serum of DM rats, but the combination of the two had an even more obvious increasing effect, which indicates a still better protective effect on the reproductive endocrine function of diabetic male rats.

[Meiotic analysis of spermatogenic cells in severe oligoasthenoteratozoospermia with chromosome 13 rearrangement].

OBJECTIVE: To explore the possible mechanisms of spermatogenic arrest in severe oligoasthenoteratozoospermia induced by supernumerary, ring-neocentric 13q12.3 --> 13q22 chromosome and reciprocal deletion. METHODS: We performed a genomic-wide high-density oaCGH analysis for a case of oligoasthenoteratozoospermia with abnormal chromosome 13 to characterize the breakpoints of the chromosome involved or the gene deletion caused by the rearrangement. We also conducted a fluorescence in situ hybridization analysis on the germ cells using probes of 13q14/13qter to observe the pairing condition of homologous chromosome 13. RESULTS: We identified by oaCGH analysis a microdeletion of 4 consecutive probes (A_16_P19757882, A_16_P02744617, A_14_ P108858 and A_16_P02744687 at chr13q12.3: 27979261 --> 28039191) with 59.93 kb between the FLT1 and POMP genes, with no annotated genes in the deleted region. The signals of 13q14 and 13qter were separated from each other in 90% of all the primary spermatocytes examined, indicating the unpairing of homologous chromosome 13 or synapse failure. CONCLUSION: Chromosomal rearrangement-induced spermatogenesis failure is caused by the unpairing of the homologous chromosomes involved in the first meiotic division of germ cells.

[Effect of annexin 5 on StAR and testosterone synthesis related enzyme in rat Leydig cells].

OBJECTIVE: To investigate the effect of annexin 5 on the expressions at mRNA levels and protein levels of StAR, P450scc, 3ß-HSD, 17α-hydroxylase and 17ß-HSD in rat Leydig cells. METHODS: The primary rat Leydig cells were cultured for 24 h and then stimulated with 10(-9) mol/L annexin 5 for 12 h and 24 h respectively. Cellular total RNA and total protein were extracted respectively. The expressions of StAR, P450scc, 3ß-HSD, and 17α-hydroxylase and 17ß-HSD(10) mRNA were detected by reverse transcription-polymerase chain reaction (RT-PCR)and the protein levels were detected by Western blotting. RESULTS: Compared with the control group, at the mRNA level, after being treated with annexin 5 for 12 h, only 17ß-HSD(10) expression had a 26% increase (P<0.05) while the others had no significant difference. The expressions of StAR, P450scc and 3ß-HSD elevated 55%, 69% and 59%(P<0.05) respectively, and 17ß-HSD(10) increased 104%(P<0.01) while 17α-hydroxylase had no significant difference after being treated with annexin 5 for 24 h. At the protein level, after being treated with annexin 5 for 12 h, 17ß-HSD expression had a 39% increase (P<0.05). After 24 h, P450scc, 3ß-HSD and 17ß-HSD elevated 35%, 88% (P<0.05) and 47% (P<0.01) respectively while StAR had no significant difference. CONCLUSION: Annexin 5 regulates testosterone synthesis by affecting the expressions of P450scc, 3ß-HSD and 17ß-HSD at gene and protein levels.

[Application of Online Mendelian Inheritance in Man to medical genetics].

Online Mendelian Inheritance in Man (OMIM, http://omim. org/) is a comprehensive, authoritative, practical and timely knowledgebase of human genes and genetic disorders. OMIM, as a genetic encyclopedia, provides an easy and straightforward access to information on human genetics to students, researchers and clinicians. This article presents an overview on the contents of OMIM and its application to medical genetics.

[Ureaplasma urealyticum infection affects sperm plasma membrane integrity in infertile men].

OBJECTIVE: To determine the impact of Ureaplasma urealyticum (Uu) infection on the integrity of sperm plasma membrane in infertile males. METHODS: Sixty-three semen samples were divided into a Uu infection group (n = 32) and a normal control group (n = 31). Conventional semen analyses were performed by computer-assisted semen analysis (CASA) and Uu detected by the culture method. The semen samples were washed with PBS and dyed by SYBR-14/PI double fluorescent staining, followed by detection of the integrity of sperm plasma membrane by flow cytometry. The percentage of the sperm with intact plasma membrane was indicated as the percentage of sperm emitting green fluorescence (SYBR-14+/PI-%). RESULTS: The Uu infection group showed a significantly decreased integrity of sperm plasma membrane ([45.14 +/- 10.69]%) and reduced percentage of grade a + b sperm ([23.29 +/- 8.81]%) as compared with the normal control group ([72.68 +/- 9.91]% and [46.32 +/- 9.54]%) (P < 0.01). But there were no significant differences in the semen volume, pH value, and sperm concentration between the two groups (P > 0.05). CONCLUSION: Uu infection decreases the integrity of sperm plasma membrane, which might be an important factor of male infertility.

[Mutation analysis of NF2 gene and clinical investigation in a Chinese family with neurofibromatosis type II].

OBJECTIVE: To report a heterozygous RNA-splicing mutation (IVS3+ 3A to C) of NF2 gene in a Chinese family with autosomal dominant neurofibromatosis type II and investigate the relationship between the genotype and phenotype. METHODS: The proband with bilateral vestibular schwannomas underwent gamma knife radiosurgery two years earlier. DNA of blood samples from all affected individuals, suspected individuals and unaffected relatives of the family was extracted and amplified to detect the polymorphisms at loci D22S1150 and D22S268 that are linked with the NF2 gene. Two-point LOD score was calculated. The promoter region, 17 exons and exon/intron boundaries of NF2 gene were amplified and sequenced for the proband. The exon 3/intron 3 boundaries of NF2 gene was amplified and sequenced for the other 3 patients, 1 suspected individual, 9 unaffected members of the family and 150 unrelated controls. RESULTS: The result of two-point linkage analysis suggested that NF2 gene was a candidate gene (Zmax= 2.109, θ = 0.00, locus D22S1150). DNA sequencing revealed a heterozygous splicing mutation in intron 3 (IVS3+ 3A to C) for the proband. Identical mutation was also observed in the other 3 patients and 1 suspected individual. No mutation was found in the 9 normal family members and 150 unrelated controls, which was consistent with the clinical diagnosis. CONCLUSION: This is the first report of familial neurofibromatosis type II with a splicing mutation of IVS3+ 3A to C of the NF2 gene. The mutation might be responsible for the neurofibromatosis type II in the family.

[Advances in rapid prenatal detection of fetal chromosome abnormalities].

Rapid prenatal detection methods, including molecular cytogenetic analysis and ultrasonographic markers, are very important for prenatal diagnosis. The use of molecular cytogenetic techniques has significantly improved the rapid detection of aneuploidy and identification of small structural abnormalities of fetal chromosomes. At present, commonly used molecular cytogenetic techniques include fluorescence in situ hybridization (FISH), quantitative fluorescence PCR (QF-PCR), multiplex ligation-dependent probe amplification (MLPA) and microarray-based comparative genomic hybridization (array CGH). There is extensive evidence that major chromosomal abnormalities can be effectively detected by ultrasonography in the first and second trimesters of pregnancy. So we can combine molecular cytogenetic techniques with ultrasonographic markers to improve the identification of aneuploidies for chromosomes and the accuracy of prenatal diagnosis, and to reduce birth defects in newborns.

[Mutation of the USP26 gene in spermatogenesis dysfunction].

The ubiquitin specific protease 26 (USP26) gene is located at Xq26.2 and present as a single exon on the X chromosome encoding for a protein of 913 amino acids. It belongs to a large family of deubiquitinating enzymes, and is exclusively expressed in the testis. There are conflicting reports on whether mutations in USP26 are associated with male infertility. This article updates the researches on the USP26 gene, its complicated relationship with male spermatogenesis dysfunction, the role of its mutation in male infertility, its geographical or ethnic distribution, and its evolution.

[Effects of semen analysis on human sperm movement parameters at different times after semen collection].

OBJECTIVE: To investigate the effects of the computer-assisted semen analysis (CASA) on human sperm movement parameters at different times after semen collection. METHODS: Ninety-two semen samples with sperm density > or = 20 x 10(6)/ml and sperm liquefaction time < 20 min were placed in a incubation box at the temperature of 37 degrees C. Then the seminal parameters were analyzed with the computer-assisted semen analysis (CASA) system at 20, 30, 60 and 90 min after semen collection. RESULTS: The percentages of grade a and b sperm were significantly lower at 30, 60 and 90 min than at 20 min (P < 0.05), so were the percentages of grade c sperm at 60 and 90 min than at 20 and 30 min (P < 0.05), but there were no significant differences in the percentage of grade c sperm between the 20-min and 30-min groups (P > 0.05). The percentages of grade a + b and a + b + c sperm were also significantly lower at 30, 60 and 90 min than at 20 min (P < 0.05). The beat cross frequency (BCF) was significantly higher at 30 min than at 20 min (P < 0.05), while the lateral head amplitude (ALH) significantly lower at 90 min than at 30 min (P < 0.05). The sperm wobbliness (WOB) was significantly higher while the curvilinear velocity (VCL) significantly lower at 90 min than at 20 and 30 min (P < 0.05). Straightness (STR) at 30, 60 and 90 min, and average path velocity (VAP) and straight line velocity (VSL) at 90 min were significantly lower than at 20 min (P < 0.05). There were no significant differences in sperm density, average motion degree (MAD) and linearity (LIN) among the four groups (P > 0.05). CONCLUSION: The interval between semen collection and sperm routine analysis needs to be standardized. The results of this study suggest that sperm movement parameters of normal liquefied semen samples are relatively constant at 30 -60 min after semen collection.