Pathogenic Variants and Genotypes of the CFTR Gene in Russian Men with Cystic Fibrosis and CBAVD Syndrome.

Pathogenic CFTR variants cause cystic fibrosis (CF), and CF-related disorders (CF-RD), including bilateral aplasia of the vas deferens (CBAVD). The spectrum of clinical manifestations depends on the CFTR genotype. The frequency and spectrum of the CFTR variants vary between populations and clinical groups. CFTR variants and genotypes were analyzed in Russian men with CF (n = 546) and CBAVD syndrome (n = 125). Pathogenic variants were detected in 93.95% and 39.2% of the CF and CBAVD alleles, respectively. The most frequent c.1521_1523del (F508del; p.Phe508del) variant was found in 541 (49.5%) CF alleles. A total of 162 CFTR genotypes were revealed in CF patients, including 152 homozygous and 394 compound-heterozygous. The most common CF-genotype was F508del/F508del (24.9%). Other frequent CF-genotypes were F508del/3849+10kbC>T, F508del/CFTRdele2,3, and F508del/E92K. CF-causing variants and/or 5T allele were found in 88% of CBAVD patients: 5T/CFTRmut (48.0%), CFTRmut/N (17.6%), CFTRmut/CFTRmut (6.4%), 5T/5T (10.4%), 5T/N (5.6%) and N/N (12.0%), with the most common CBAVD-genotype being F508del/5T (29.6%). The allele frequencies of F508del, CFTRdele2,3 394delTT, and 3849+10kbC>T were significantly higher in CF patients. L138ins/L138ins, 2184insA/E92K, and L138ins/N genotypes were found in CBAVD, but not in CF patients. The results indicate certain differences in the frequency of some CFTR variants and genotypes in Russian CF and CBAVD patients.

Detection and evaluation of different morphological forms of Mycoplasma hominis in human semen.

Recently discovered microcolonial forms of Mycoplasma hominis (M. hominis) and their impact on human spermatogenesis are studied. The spermatozoa of 125 fertile men (sperm donors; from Reprobank [Reproductive Tissue Bank, Moscow, Russia]) and of 93 patients with fertility problems (from the Federal State Budgetary Institution "Research Centre for Medical Genetics [RCMG]", Moscow, Russia) were used. Classical colonies of M. hominis and microcolonies were detected by molecular biological methods, culture of bacteria, and transmission electron microscopy. The unique structure of microcolonial cells, in which the cytoplasmic cylinder is surrounded by concentric electron-dense and electron-light layers with a periodicity of 12-14 nm, and the ability of microcolonial cells to attach to spermatozoa are shown. In patients with lower sperm quality, microcolonies of M. hominis were detected 2.5 times more frequently than classical colonies. The detection of microcolonies in the ejaculate and the frequent isolation of microcolonies from sperm samples of patients with fertility problems suggest that microcolonial cells may be one cause of infertility.

L138ins Variant of the CFTR Gene in Russian Infertile Men.

(1) Introduction: Pathogenic variants in the CFTR (Cystic Fibrosis Transmembrane conductance Regulator, OMIM: 602421) gene cause Cystic Fibrosis (CF, OMIM: 219700) and CF-related disorders (CF-RD), often accompanied by obstructive azoospermia due to congenital bilateral aplasia of vas deferens (CBAVD, OMIM: 277180) in male patients. The L138ins (c.413_415dup; p. (Leu138dup)) is a mild variant in the CFTR gene that is relatively common among CF-patients in Slavic populations. The frequency of this variant in Russian infertile men has not been sufficiently studied; (2) Materials and Methods: The sample consisted of 6033 Russian infertile men. The patients were tested for 22 common in Russian populations pathogenic variants of the CFTR gene and the IVS9Tn-polymorphic locus of the intron 9. Molecular-genetic studies were performed using amplified fragment length polymorphism (AFLP-PCR), multiplex ligation-dependent probe amplification (MLPA), and nested PCR (for analysis of the IVS9Tn-polymorphic locus); (3) Results: Pathogenic variants in the CFTR were detected in 3.9% of patients. The most frequent variants were F508del and CFTRdele2.3(21kb), accounted for 61.0% and 7.1% of detected variants, respectively. The L138ins variant was detected in 17 (0.28%) individuals: one of them was homozygous, 10 patients were heterozygous, and 6 patients were compound-heterozygous (F508del/L138ins, n = 4; L138ins/N1303K, n = 1; L138ins/5T, n = 1). Two pathogenic CF-causing variants in the CFTR gene were detected in 8 patients, including 7 compound heterozygous (F508del/L138ins, n = 4; F508del/N1303K, n = 1; 2184insA/E92K, n = 1; 3849+10kbC>T/E92K, n = 1) and one homozygous (L138ins/L138ins). The L138ins variant was found in 7 out of 16 (43.75%) chromosomes in six of these patients. The most common pathogenic variant, F508del, was identified in five out of them, in 5 of 16 (31.25%) chromosomes. The allele frequency (AF) of the L138ins variant in the sample has been found to be 0.0014.; (4) Conclusions: The L138ins variant of the CFTR gene is the third most common variant after F508del and CFTRdele2.3(kb) among Russian infertile men.

Comprehensive semen examination in patients with pancreatic-sufficient and pancreatic-insufficient cystic fibrosis.

We examined a cohort of 93 cystic fibrosis (CF) male patients who were pancreatic-sufficient (PS-CF; n=40) or pancreatic-insufficient (PI-CF; n = 53). Complex semen examination was performed, including standard semen analysis, quantitative karyological analysis (QKA) of immature germ cells (IGCs), transmission electronic microscopy (TEM), biochemical analysis, and sperm DNA fragmentation by terminal deoxynucleotidyl transferase-mediated dUTP nickend labeling (TUNEL) assay. Azoospermia was diagnosed in 83 (89.2%) patients. The other 10 (10.8%) patients were found to be nonazoospermic and showed various spermatological diagnoses (asthenozoospermia, n = 2; asthenoteratozoospermia, n = 3; oligoasthenozoospermia, n = 1; oligoasthenoteratozoospermia, n = 3; and normozoospermia, n = 1) with no specific morphological abnormalities. Oligospermia was detected in 89.2% azoospermic and 30.0% nonazoospermic patients. Low seminal pH (<7.0) was found in 74 (89.2%) of 83 azoospermic patients. Moderate leukocytospermia (2.0 × 10 6 -2.2 × 10 6 ml -1 ) was revealed in 2.4% azoospermic and 40.0% nonazoospermic semen samples. The signs of partial meiotic arrest at prophase I were found in 4 of 6 nonazoospermic patients examined by QKA of IGCs. The content of fructose and citrate was low in oligospermic and normal in nonoligospermic semen samples. An increased percentage (>30%) of spermatozoa with noncondensed ("immature") chromatin was revealed in 2 of 6 nonazoospermic semen samples analyzed by TEM.

Russian Regional Differences in Allele Frequencies of CFTR Gene Variants: Genetic Monitoring of Infertile Couples.

A male factor, commonly associated with poor semen quality, is revealed in about 50% of infertile couples. CFTR gene (Cystic Fibrosis Transmembrane Conduction Regulator) variants are one of the common genetic causes of azoospermia-related male infertility. Notably, the spectrum and frequency of pathogenic CFTR variants vary between populations and geographical regions. In this work, we made an attempt to evaluate the allele frequency (AF) of 12 common CFTR variants in infertile Russian men and healthy individuals from different districts of Russia. Because of the limited number of population-based studies on Russian individuals, we characterized the population AFs based on data from the Registry of Russian cystic fibrosis (CF) patients. In addition to the CF patient registry, we estimated the local frequencies of the same set of variants based on the results of genotyping of CF patients in local biocollections (from St. Petersburg and Yugra regions). AFs of common CFTR variants calculated based on registry and biocollection data showed good concordance with directly measured population AFs. The estimated region-specific frequencies of CFTR variants allowed us to uncover statistically significant regional differences in the frequencies of the F508del (c.1521_1523del; p.Phe508del) and CFTRdele2,3(21kb) (c.54-5940_273+10250del21kb; p.Ser18ArgfsX) variants. The data from population-based studies confirmed previous observations that F508del, CFTRdele2,3(21kb), and L138ins (c.413_415dup; p.Leu138dup)variants are the most abundant among infertile patients, and their frequencies are significantly lower in healthy individuals and should be taken into account during genetic monitoring of the reproductive health of Russian individuals.

Genetics of Oocyte Maturation Defects and Early Embryo Development Arrest.

Various pathogenic factors can lead to oogenesis failure and seriously affect both female reproductive health and fertility. Genetic factors play an important role in folliculogenesis and oocyte maturation but still need to be clarified. Oocyte maturation is a well-organized complex process, regulated by a large number of genes. Pathogenic variants in these genes as well as aneuploidy, defects in mitochondrial genome, and other genetic and epigenetic factors can result in unexplained infertility, early pregnancy loss, and recurrent failures of IVF/ICSI programs due to poor ovarian response to stimulation, oocyte maturation arrest, poor gamete quality, fertilization failure, or early embryonic developmental arrest. In this paper, we review the main genes, as well as provide a description of the defects in the mitochondrial genome, associated with female infertility.

The effect of Robertsonian translocations on the intranuclear positioning of NORs (nucleolar organizing regions) in human sperm cells.

Only a few studies have described sperm chromosome intranuclear positioning changes in men with reproductive failure and an incorrect somatic karyotype. We studied the influence of Robertsonian translocations on the acrocentric chromosome positioning in human sperm cells. The basis of the analysis was the localization of NORs (nucleolar organizing regions) in sperm nuclei from three Robertsonian translocation carriers, namely, rob(13;22), rob(13;15) and rob(13;14), with a known meiotic segregation pattern. All three carriers presented with a similar percentage of genetically normal sperm cells (i.e., approximately 40%). To visualize NORs, we performed 2D-FISH with directly labelled probes. We used the linear and radial topologies of the nucleus to analyse the NORs distribution. We found an affected positioning of NORs in each case of the Robertsonian translocations. Moreover, the NORs tended to group, most often in two clusters. Both in Robertsonian carriers and control sperm cells, NORs mostly colocalized in the medial areas of the nuclei. In the case of the Roberstonian carriers, NORs were mostly concentrated in the peripheral part of the medial area, in contrast to control sperm cells in which the distribution was more dispersed towards the internal area.

Genes associated with testicular germ cell tumors and testicular dysgenesis in patients with testicular microlithiasis.

Testicular microlithiasis (TM) is one of the symptoms of testicular dysgenesis syndrome (TDS). TM is particularly interesting as an informative marker of testicular germ cell tumors (TGCTs). KIT ligand gene (KITLG), BCL2 antagonist/killer 1 (BAK1), and sprouty RTK signaling antagonist 4 (SPRY4) genes are associated with a high risk of TGCTs, whereas bone morphogenetic protein 7 gene (BMP7), transforming growth factor beta receptor 3 gene (TGFBR3), and homeobox D cluster genes (HOXD) are related to TDS. Using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis, we investigated allele and genotype frequencies for KITLG (rs995030, rs1508595), SPRY4 (rs4624820, rs6897876), BAK1 (rs210138), BMP7 (rs388286), TGFBR3 (rs12082710), and HOXD (rs17198432) in 142 TGCT patients, 137 TM patients, and 153 fertile men (control group). We found significant differences in the KITLG GG_rs995030 genotype in TM (P = 0.01) and TGCT patients (P = 0.0005) compared with the control. We also revealed strong associations between KITLG_rs1508595 and TM (G allele, P = 0.003; GG genotype, P = 0.01) and between KITLG_rs1508595 and TGCTs (G allele, P = 0.0001; GG genotype, P = 0.0007). Moreover, there was a significant difference in BMP7_rs388286 between the TGCT group and the control (T allele, P = 0.00004; TT genotype, P = 0.00006) and between the TM group and the control (T allele, P = 0.04). HOXD also demonstrated a strong association with TGCTs (rs17198432 A allele, P = 0.0001; AA genotype, P = 0.001). Furthermore, significant differences were found between the TGCT group and the control in the BAK1_rs210138 G allele (P = 0.03) and the GG genotype (P = 0.01). KITLG and BMP7 genes, associated with the development of TGCTs, may also be related to TM. In summary, the KITLG GG_rs995030, GG_rs1508595, BMP7 TT_rs388286, HOXD AA_rs17198432, and BAK1 GG_rs210138 genotypes were associated with a high risk of TGCT development.

Global methylation status of sperm DNA in carriers of chromosome structural aberrations.

Male infertility might be clearly associated with aberrant DNA methylation patterns in human spermatozoa. An association between oxidative stress and the global methylation status of the sperm genome has also been suggested. The aim of the present study was to determine whether the global sperm DNA methylation status was affected in the spermatozoa of carriers of chromosome structural aberrations. The relationships between the 5-methylcytosine (m 5 C) levels in spermatozoa and chromatin integrity status were evaluated. The study patients comprised male carriers of chromosome structural aberrations with reproductive failure (n = 24), and the controls comprised normozoospermic sperm volunteers (n = 23). The global m 5 C level was measured using thin-layer chromatography (TLC) and immunofluorescence (IF) techniques. The sperm chromatin integrity was assessed using aniline blue (AB) staining and TUNEL assay. The mean m 5 C levels were similar between the investigated chromosome structural aberrations carriers (P) and controls (K). However, sperm chromatin integrity tests revealed significantly higher values in chromosomal rearrangement carriers than in controls (P < 0.05). Although the potential relationship between sperm chromatin integrity status and sperm DNA fragmentation and the m 5 C level juxtaposed in both analyzed groups (P vs K) was represented in a clearly opposite manner, the low chromatin integrity might be associated with the high hypomethylation status of the sperm DNA observed in carriers of chromosome structural aberrations.

A 3-year-old boy with ovotestes: gender reassignment and surgical management.

OBJECTIVE: We report a male patient with ovotesticular disorder of sex development (OTDSD), resulting from structurally abnormal Y chromosome. CASE REPORT: A 3-year-old boy was admitted to the Surgical Pediatric Department for masculinizing reconstruction. He had a clitorophallus, bifid scrotum, perineal hypospadias and bilateral impalpable gonads. Pelvic ultrasound and laparoscopy showed a uterus and two gonads with primary ovarian follicles. Chromosome analysis detected a mos 47,XX,mar/46,XX karyotype. Complex genetic evaluation revealed that the marker was Yp isochromosome. Surgical care included a feminizing genitoplasty and separation of the gonads with total excision of testicular tissue. CONCLUSIONS: The presented case emphasizes the importance of a systematic approach to the investigation and management of the patients with ovotesticular DSD. It also raises the important issue about gender reassignment in intersex individuals in mid-childhood.