Browsing by Author "Erenpreiss, Juris"

Now showing 1 - 10 of 10
  • No Thumbnail Available
    Item
    Case of Inherited Partial AZFa Deletion without Impact on Male Fertility
    (2019-10-31) Alksere, Baiba; Berzina, Dace; Dudorova, Alesja; Conka, Una; Andersone, Santa; Pimane, Evija; Krasucka, Sandra; Blumberga, Arita; Dzalbs, Aigars; Grinfelde, Ieva; Vedmedovska, Natalija; Fodina, Violeta; Erenpreiss, Juris; Rīga Stradiņš University
    Male factor infertility accounts for 40–50% of all infertility cases. Deletions of one or more AZF region parts in chromosome Y are one of the most common genetic causes of male infertility. Usually full or partial AZF deletions, including genes involved in spermatogenesis, are associated with spermatogenic failure. Here we report a case of a Caucasian man with partial AZFa region deletion from a couple with secondary infertility. Partial AZFa deletion, involving part of USP9Y gene appears to be benign, as we proved transmission from father to son. According to our results, it is recommended to revise guidelines on markers selected for testing of AZFa region deletion, to be more selective against DDX3Y gene and exclude probably benign microdeletions involving only USP9Y gene.
  • No Thumbnail Available
    Item
    Genetically determined dosage of Follicle-Stimulating Hormone (FSH) affects male reproductive parameters
    (2011-09) Grigorova, Marina; Punab, Margus; Ẑilaitiene, Birute; Erenpreiss, Juris; Ausmees, Kristo; Matuleviĉius, Valentinas; Tsarev, Igor; Jørgensen, Niels; Laan, Maris; Rīga Stradiņš University
    Context: The detailed role of FSH in contributing to male testicular function and fertility has been debated. We have previously identified the association between the T-allele of the FSHB promoter polymorphism (rs10835638; G/T, -211 bp from the mRNA start) and significantly reduced male serum FSH. Objective: In the current study, the T-allele carriers of the FSHB -211 G/T single nucleotide polymorphism represented a natural model for documenting downstream phenotypic consequences of insufficient FSH action. Design and Subjects: We genotyped rs10835638 in the population-based Baltic cohort of young men (n=1054; GG carriers, n=796; GT carriers, n=244; TT carriers, n=14) recruited by Andrology Centres in Tartu, Estonia; Riga, Latvia; and Kaunas, Lithuania. Marker-trait association testing was performed using linear regression (additive, recessive models) adjusted by age, body mass index, smoking, and recruitment center. Results: Serum hormones directly correlated with the T-allele dosage of rs10835638 included FSH (additive model, P=1.11×10 -6; T-allele effect, -0.41 IU/liter), inhibin-B (P=2.16×10 -3; T-allele effect, -14.67 pg/ml), and total testosterone (P = 9.30 × 10 -3; T-allele effect, -1.46 nmol/liter). Parameters altered only among TT homozygotes were reduced testicular volume (recessive model, P = 1.19 × 10 -4; TT genotype effect, -9.47 ml) and increased serum LH (P = 2.25 × 10 -2; TT genotype effect, 1.07 IU/liter). The carrier status of rs10835638 alternative genotypes did not affect sperm motility and morphology, calculated free testosterone, serum SHBG, and estradiol concentrations. Conclusion: We showed for the first time that genetically determined low FSH may have wider downstream effects on the male reproductive system, including impaired testes development, altered testicular hormone levels (inhibin-B, total testosterone, LH), and affected male reproductive potential.
  • No Thumbnail Available
    Item
    Idiopathic infertility as a feature of genome instability
    (2021-06-29) Puzuka, Agrita; Alksere, Baiba; Gailite, Linda; Erenpreiss, Juris; Scientific Laboratory of Molecular Genetics; Department of Biology and Microbiology
    Genome instability may play a role in severe cases of male infertility, with disrupted spermatogenesis being just one manifestation of decreased general health and increased morbidity. Here, we review the data on the association of male infertility with genetic, epigenetic, and environmental alterations, the causes and consequences, and the methods for assessment of genome instability. Male infertility research has provided evidence that spermatogenic defects are often not limited to testicular dysfunction. An increased incidence of urogenital disorders and several types of cancer, as well as overall reduced health (manifested by decreased life expectancy and increased morbidity) have been reported in infertile men. The pathophysiological link between decreased life expectancy and male infertility supports the notion of male infertility being a systemic rather than an isolated condition. It is driven by the accumulation of DNA strand breaks and premature cellular senescence. We have presented extensive data supporting the notion that genome instability can lead to severe male infertility termed “idiopathic oligo-astheno-teratozoospermia.” We have detailed that genome instability in men with oligo-astheno-teratozoospermia (OAT) might depend on several genetic and epigenetic factors such as chromosomal heterogeneity, aneuploidy, micronucleation, dynamic mutations, RT, PIWI/piRNA regulatory pathway, pathogenic allelic variants in repair system genes, DNA methylation, environmental aspects, and lifestyle factors.
  • No Thumbnail Available
    Item
    Late-onset hypogonadism : Review of the problem
    (2010-01-01) Požarskis, Anatolijs; Erenpreiss, Juris; Rīga Stradiņš University
    The study investigates late-onset hypogonadism (LOH), its influence on male joint system, build, cardiovascular system, haematopoesis, cognitive functions, and sexual function. LOH is a clinical and biochemical syndrome, which is related to aging and characterised by typical symptoms and a decreased serum testosterone level. It causes a worsened life quality, and the functions of various organs are badly affected. LOH is diagnosed when the testosterone level is below 8 nmol/l (230 ng/dl) or it is at the border-line (from 8 and 12 nmol/l) and there are LOH clinical symptoms such as a decreased libido, erectile dysfunction, reduced muscular mass and strength, increased obesity, reduced bone mineral density, osteoporosis, and depression. All patients with LOH are indicated testosterone replacement therapy (TRT). TRT is contra-indicated to patients suffering from prostate or thoracic gland carcinoma. In case of erythrocytosis (haematocrit > 52%), severe heart failure, marked prostate benign hyperplasia with the obstruction of urine pathways, and obstructive sleep apnoe syndrome, TRT is relatively contra-indicated and should not be started unless these dysfunctions are cured. The treatment of LOH requires thorough patient monitoring, which includes digital rectal examination and Prostate Specific Antigen conducted after 3-6 months and 12 months in the first treatment year. It is necessary to determine the total blood count after 3-4 and 12 months in the first treatment year and afterwards once a year.
  • No Thumbnail Available
    Item
    A novel EDA variant causing X-linked hypohidrotic ectodermal dysplasia : Case report
    (2021-12) Alksere, Baiba; Kornejeva, Liene; Grinfelde, Ieva; Dzalbs, Aigars; Enkure, Dace; Conka, Una; Andersone, Santa; Blumberga, Arita; Nikitina-Zake, Liene; Kangare, Liga; Radovica-Spalvina, Ilze; Vasiljeva, Inta; Gailite, Linda; Erenpreiss, Juris; Fodina, Violeta; Rīga Stradiņš University
    Hereditary ectodermal dysplasias are a complex group of inherited disorders characterised by abnormalities in two or more ectodermal derivatives (skin, nails, sweat glands, etc.). There are two main types of these disorders – hidrotic and hypohidrotic/anhidrotic ectodermal dysplasias. Hypohidrotic ectodermal dysplasia (HED) or Christ-Siemens-Touraine syndrome (OMIM: 305100) occurs in 1 out of 5000–10,000 births [19] and has an X-linked recessive inheritance pattern (X-linked hypohydrotic ectodermal dysplasia – XLHED) [2]. The main cause of XLHED is a broad range of pathogenic variants in the EDA gene (HGNC:3157, Xq12-13) which encodes the transmembrane protein ectodysplasin-A [4]. We report here the case of a patient with a novel inherited allelic variant in the EDA gene – NM_001399.5:c.337C>T (p.Gln113*) – in the heterozygous state. Targeted family member screening was conducted and other carriers of this EDA gene pathogenic variant were identified and phenotypically characterised. The patient subsequently underwent in vitro fertilisation with preimplantation genetic testing for monogenic diseases (PGT-M).
  • No Thumbnail Available
    Item
    Reproductive physiology in young men is cumulatively affected by FSH-action modulating genetic variants : FSHR -29G/A and c.2039 A/G, FSHB -211G/T
    (2014-04-09) Grigorova, Marina; Punab, Margus; Punab, Anna Maria; Poolamets, Olev; Vihljajev, Vladimir; Žilaitiene, Birute; Erenpreiss, Juris; Matulevičius, Valentinas; Laan, Maris; Scientific Laboratory of Molecular Genetics
    Follicle-Stimulating Hormone Receptor (FSHR) -29G/A polymorphism (rs1394205) was reported to modulate gene expression and reproductive parameters in women, but data in men is limited. We aimed to bring evidence to the effect of FSHR -29G/A variants in men. In Baltic young male cohort (n = 982; Estonians, Latvians, Lithuanians; aged -0.2±2.0 years), the FSHR -29 A-allele was significantly associated with higher serum FSH (linear regression: effect 0.27 IU/L; P = 0.0019, resistant to Bonferroni correction for multiple testing) and showed a non-significant trend for association with higher LH (0.19 IU/L) and total testosterone (0.93 nmol/L), but reduced Inhibin B (-7.84 pg/mL) and total testes volume (effect -1.00 mL). Next, we extended the study and tested the effect of FSHR gene haplotypes determined by the allelic combination of FSHR -29G/A and a well-studied variant c.2039 A/G (Asn680Ser, exon 10). Among the FSHR -29A/2039G haplotype carriers (A-Ser; haplotype-based linear regression), this genetic effect was enhanced for FSH (effect 0.40 IU/L), Inhibin B (-16.57 pg/mL) and total testes volume (-2.34 mL). Finally, we estimated the total contribution of three known FSH-action modulating SNPs ( FSHB -211G/T; FSHR -29G/A, c.2039 A/G) to phenotypic variance in reproductive parameters among young men. The major FSH-action modulating SNPs explained together 2.3%, 1.4%, 1.0 and 1.1% of the measured variance in serum FSH, Inhibin B, testosterone and total testes volume, respectively. In contrast to the young male cohort, neither FSHR -29G/A nor FSHR haplotypes appeared to systematically modulate the reproductive physiology of oligozoospermic idiopathic infertile patients (n = 641, Estonians; aged 31.5±6.0 years). In summary, this is the first study showing the significant effect of FSHR -29G/A on male serum FSH level. To account for the genetic effect of known common polymorphisms modulating FSH-action, we suggest haplotype-based analysis of FSHR SNPs (FSHR -29G/A, c.2039 A/G) in combination with FSHB -211G/T testing.
  • No Thumbnail Available
    Item
    Sperm concentration in Latvian military conscripts as compared with other countries in the Nordic-Baltic area
    (2005-08) Tsarev, Igor; Gagonin, Valerij; Giwercman, Aleksander; Erenpreiss, Juris
    Recent studies of semen quality in men from the general population gave rise to the hypothesis of an East-West gradient in semen quality in the Nordic-Baltic area, with the highest sperm counts in Estonia, Lithuania and Finland, and the lowest in Denmark (30% difference in mean concentration). Genetic, lifestyle-related and environmental factors - alone or in combination - were suggested to be responsible for these differences. The aim of this study was to assess sperm concentration in men from the general population in Latvia and to investigate the impact of ethnic and lifestyle-related factors on this marker of male reproductive health. A total of 133 military conscripts from Latvia were investigated. We found that sperm counts among Latvian adolescents were at the same level (mean 74, median 63 × 106/mL) as those previously reported from Estonia, Lithuania and Finland. Sperm concentration was somewhat higher than in Sweden without reaching the level of statistical significance (mean difference 3 × 106/mL; 95% CI: -10, 16 × 106/mL), and statistically significantly higher that in Denmark (mean difference: 17 × 106/mL; 95% CI: 5, 2 × 106/mL). The study also revealed an impact of ethnic factors on sperm numbers. Sperm concentration was significantly higher in men with both parents born in Latvia (77 ± 60 × 106/mL), compared with men with both parents born outside Latvia (55 ± 45 × 106/mL, p = 0.03).
  • No Thumbnail Available
    Item
    Sperm DNA damage in men from infertile couples
    (2008-09) Erenpreiss, Juris; Elzanaty, Saad; Giwercman, Aleksander; Scientific Laboratory of Molecular Genetics
  • No Thumbnail Available
    Item
    Toluidine Blue Test for Sperm DNA Integrity and Elaboration of Image Cytometry Algorithm
    (2003-03) Erenpreisa, Jekaterina; Erenpreiss, Juris; Freivalds, Talivaldis; Slaidina, Maija; Krampe, Rasma; Butikova, Jelena; Ivanov, Andrey; Pjanova, Dace
    Background: Sperm DNA integrity is of paramount importance in the prognosis of fertility. We applied image cytometry to a toluidine blue (TB) test we recently proposed. Methods: Sperm samples from 33 men were assayed for standard sperm parameters and classified as normal or abnormal. Sperm smears were subjected to the TB test, DNA denaturation testing with acridine orange (AO), and terminal deoxyuridine triphosphate biotin nick end labeling (TUNEL). In CCD image analysis, TB-stained sperm cell heads were microscopically assigned to one of four color groups (dark, blue, light violet, and light blue). The optical densities of 6,600 cells in green and red CCD images were used to elaborate an algorithm for discrimination of these groups. Results: The proportions of sperm in TB color groups, as estimated with the developed image cytometry algorithm, correlated with microscopic features. The number of TB dark cells correlated with the number of AO-red and TUNEL+ cells. The proportion of TB dark cells in normal samples did not exceed 35%. Light-blue sperm cell heads prevailed in normal samples, whereas dark and blue sperm cell heads dominated in abnormal samples. Conclusions: The TB test was suitable for the assessment of sperm cell DNA integrity. The elaborated image cytometry algorithm can be used for this purpose and for finer determination of sperm nucleus status.
  • No Thumbnail Available
    Item
    When Three Isn't a Crowd : A Digyny Concept for Treatment-Resistant, Near-Triploid Human Cancers
    (2019-07) Salmina, Kristine; Gerashchenko, Bogdan, I; Hausmann, Michael; Vainshelbaum, Ninel M.; Zayakin, Pawel; Erenpreiss, Juris; Freivalds, Talivaldis; Cragg, Mark S.; Erenpreisa, Jekaterina; Rīga Stradiņš University