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 Table of Contents 
ORIGINAL ARTICLE
Year : 2019  |  Volume : 8  |  Issue : 10  |  Page : 3356-3361  

Correlation of follicle-stimulating hormone receptor gene Asn 680 Ser (rs6166) polymorphism with female infertility


1 Department of Obstetrics and Gynecology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
2 Department of Anatomy, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
3 Department of Geriatric Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India

Date of Submission24-Aug-2019
Date of Decision30-Aug-2019
Date of Acceptance19-Sep-2019
Date of Web Publication31-Oct-2019

Correspondence Address:
Prof. Royana Singh
Department of Anatomy, Institute of Medical Science, Banaras Hindu University, Varanasi - 221 005, Uttar Pradesh
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/jfmpc.jfmpc_685_19

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  Abstract 


Background and Aims: Female infertility is a complex multifactorial, and polygenic disease associated with genetic factors plays an essential role in its formation and follicle development, oocyte maturation, and steroidogenesis regulation in the ovary. The aim here is too study the genetic association between follicle-stimulating hormone receptor (FSHR) Asn680Ser; (rs6166) gene polymorphism with female Infertility in our population. Methods: In this prospective case-control study, we enrolled 106 infertile and 164 unrelated healthy control individuals. Genomic DNA was extracted from the 5 ml of venous blood using the modified salting-out method. A polymerase chain reaction-amplified exon 10 of FSHR and purified PCR products were sequenced on an ABI 3730XL DNA sequencer. The data were analyzed statistically. Results: We found that the presence of rare allele ”G” and heterozygous and common homozygous genotypes significantly increased the risk of female infertility. No significant change in the FSHR 191756 G >A genotype frequency was observed, regardless of chromosomal integrity. The genotype frequency distribution of locus 680 was consistent with the Hardy–Weinberg Equilibrium (HWE) in both groups (P > 0.05). Conclusion: No significant differences were found in allelic variants frequency and genotype distribution between each category of subjects when analyzing the FSHR SNPs in the exonic region (P value >0.05). FSHR Asn680Ser polymorphisms and female infertility (P > 0.05). Variations in FSHR gene have an essential influence on ovarian function and can account for several defects of female fertility. FSHR Asn680Ser (rs6166) gene polymorphism is associated with female infertility and can be used as a relevant molecular biomarker to identify the risk of infertility in our population. This finding can be important for disease pathogenesis.

Keywords: Follicle-stimulating hormone receptor, gene polymorphisms, infertility, rs6166 polymorphism


How to cite this article:
Rai S, Ashish, Kumari P, Singh A, Singh R. Correlation of follicle-stimulating hormone receptor gene Asn 680 Ser (rs6166) polymorphism with female infertility. J Family Med Prim Care 2019;8:3356-61

How to cite this URL:
Rai S, Ashish, Kumari P, Singh A, Singh R. Correlation of follicle-stimulating hormone receptor gene Asn 680 Ser (rs6166) polymorphism with female infertility. J Family Med Prim Care [serial online] 2019 [cited 2019 Nov 21];8:3356-61. Available from: http://www.jfmpc.com/text.asp?2019/8/10/3356/270021




  Introduction Top


Infertility is an inability to become clinically pregnant after 12 months or more of regular sexual intercourse. Infertility affects up to 15% of reproductive-aged couples worldwide. According to the World Health Organization (WHO) estimate, the overall prevalence of infertility in India is between 3.9 to 16.8%.[1] In Indian states, prevalence of infertility varies from state to state, such as 3.7 percent in Uttar Pradesh.[2] Female infertility is a complex disease which involves both environmental and genetic factors.[3] Genetic causes of infertility can be divided into cytogenetic anomalies and gene defects, aberrances[4] Several genes have been associated with Infertility including FMR1 and Bone Morphogenetic Protein 15 (BMP15).[5] Among autosomal gene mutations often found in women with POF are AR, CDKN1B, CYP19A1, GDF9, FIGLA, FOXL2, FOXO1a, FOXO3a, INHA, LHX8, NOBOX, NANOS3, SALL4 and FSHR.[6] Follicle-stimulating hormone 678 amino acids play a significant role in the development of follicles and regulation of steroidogenesis in the ovary and granulosa cells in the ovary.[7] The lessen of infertility is genetic and may be due to inactivating mutations in the gonadotropin and gonadotropin receptor genes.[8] While mutations affecting the FSHR gene are sporadic, polymorphism of the FSHR gene seems to be a common phenomenon.[9] FSHR inactivating mutations may cause premature ovarian failure, primary or secondary amenorrhea, infertility.[10] The interaction between FSH and its receptor is crucial for follicular development and maturation, which makes it indispensable for female fertility.[11] The FSHR Gene calculated molecular mass of ranges between 75 and 76.5 kDa and belongs to family 1 of G-protein coupled receptors encoded by this protein and consists of 678 amino acids (695 considering the first 17 amino acids that encode a hydrophobic signal peptide), grouped in 7 transmembrane domains.[12] The FSHR gene, which consisted of 10 exons and 9 introns, has been mapped to chromosome 2p21.[13] Most of the extracellular domain encodes 9 exons; the C-terminal part of the extracellular domain, the intracellular domain, and the Transmembrane domain, are encoded by the large exon 10 (1234 bp).[14] Some naturally occurring mutations in the FSH receptor have been reported in subjects with infertility, and until now, there are more than 900 SNPs (Single nucleotide polymorphism).[15] FSHR gene is polymorphic mainly two sites associated in allelic variations, and finally, in an altered amino acid sequence on the receptor protein.[16] More commonly studied in FSHR, position 307 that changes an alanine to threonine (Ala307Thr) and location 680 that switches an asparagine to serine (Asn680Ser).[17] Our study aims to correlation of follicle-stimulating hormone receptor gene Asn 680 Ser (rs6166) polymorphism with female infertility in Indian women.


  Methods Top


Study subjects

In this cross sectional study, we enrolled female patients with infertility (N = 106), controls (N = 164) (30.76 ± 4.53). The control subjects recruited had a regular menstrual cycle, and no history of pregnancy loss or other complications were recruited from the Department of Obstetrics and Gynecology, Sir Sunderlal Hospital, Institute of Medical Sciences, Banaras Hindu University, Varanasi.

A questionnaire was completed by each infertility patient to record the details of their lifestyle, habits, and family history. All subjects were of Indian ethnicity from eastern Uttar Pradesh and Bihar state of northern India. The average age of the infertile female included in the study in age was 18 to 37(mean age [±SD] 26.89 ± 4.01), years. The study was approved by the Institutional Medical Ethical Committee (No. Dean/2014 -15/EC/1489) on 17/10/2015 and all participants provided their consent. The control group consisted of 164 proven fertile, healthy females with a history of regular menstrual cyclicity.

Hormonal and biochemical

Analysis of Hormonal and Biochemical parameters serum; preparation was done immediately using a centrifuge, and stored in −20°C until processing of biochemical parameters. Fasting plasma glucose (enzymatic colorimetric method), serum FSH (Hitachi analyzer), LH, insulin, serum testosterone (free and total), were measured by Enzyme-linked immunosorbent assay (ELISA) in both patients and controls [Table 1]. Among 106 patients, the mean serum FSH concentration was 5.48 ± 1.98 mIU/mL, and the TSH level was 5.97 (2.55-10.4) mIU/mL. The association of serum FSH and TSH with Asn680Ser polymorphism were not statistically significant, P = 0.619; P = 0.963, respectively [Table 2].
Table 1: Main characteristics of study participants

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Table 2: Endocrine profiles* of the patient group (n=106) *Median (min-max)

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Genomic DNA extraction and genotyping

Genomic DNA was extracted from the 5 ml of venous blood using a modified salting-out method.[18] The DNA concentration was determined using a spectrophotometric method by reading absorbance at 260 nm, followed by dilution to 100 ng (working concentration) in TE Buffer. The quality of DNA preparation was assessed on 2% agarose gel electrophoresis. Chromosomal analysis was performed on phytohaemagglutinin (PHA)-stimulated peripheral lymphocyte cultures using standard conventional cytogenetic methods.[19] Primer designing of rs6166/Asn680Ser FSHR Gene was performed using ensemble genome browser and primer3 web primers tools. The primer sequence is F, 5′TTTGTGGTCATCTGTGGCTGC -3′and R, 5′-CAAAGGCAAGACTGAATTATCATT-3′. Each reaction was performed in 20 μL reaction volume, where 100 ng DNA template was added to 1 μL of each primer (10 pmol), 160 mmol/L dNTP, 1 × PCR buffer, and 1 U Taq DNA polymerase (NEB) and ddH2O, under the PCR amplification, was performed by an initial step under the following conditions. 35 cycles of amplification were performed with the use of the applied biosystems PCR System. A denaturation step at 95°C for 5 min, followed by 35 cycles of an at 95°for 45 sec, annealing at 62°C for 45 sec, Extension at 72°C for 45 sec and a final Extension step 72°C for 5 min in a Thermocycler. The final amp icons were of 519 bp respectively. The amplified products were run on 2% agarose gel electrophoresis, stained with ethidium bromide and photographed.

DNA sequencing

To find SNPs demonstrated in infertility patients, with Control to illustrate gene variants, exon 10 of FSHR (519bp) was amplified from genomic DNA using a standard primer. The purified PCR products of the amplified FSHR gene region were sequenced and analyzed on an ABI 3730XL DNA sequencer. (Eurofins Genomics India Pvt. Ltd.). The obtained sequences of these samples were analyzed at National Center for Biotechnology Information (NCBI) website using the Multiple Sequence Alignment by CLUSTALW search tool and examined SNPs presence of using an analysis tools FinchTV 1.4.0 developed by Geospiza, Inc.

Statistical analysis

Case-control study

Hardy-Weinberg equilibrium (HWE) Testing of Biological Ascertainment performed with the use of the Chi-square test with two degrees of freedom to compare the observed alleles and genotype frequencies. Among the subjects with the expected genotype frequencies were compared between Case and controls their respective 95% confidence intervals (95%CIs) were calculated to assess the relative risk (RR) conferred by a particular allele and genotype. All statistical analyses were performed using the Statistical Package for the Social Sciences (SPSS).


  Results Top


Case-control study of FSHR gene polymorphisms in infertile female.

The genotype frequencies in the control group for all of the polymorphisms fitted well in the Hardy-Weinberg equilibrium (P >.05). The results of this study presented no significant differences between the Infertility and Control. There were polymorphisms in the FSHR coding region in infertile women from India [Figure 1]. The results of the statistical analysis of the distribution of FSHR polymorphism genotype and allele frequencies between infertile female and controls are shown in [Table 3]a and 3b. The presence of rare allele “G” and heterozygous and Common homozygous genotypes significantly increased the case compared with the control subjects. Similarly, the frequency of heterozygous and rare homozygous genotypes was significantly higher in the patients compared with the control subjects, indicating its association with infertility [Table 3]a and [Table 3]b. The genotypes of FSHR codons 680 in patients and controls were in Hardy–Weinberg Equilibrium (HWE) and showed a demographic representation. However, there were statistically no significant separate associations between the Asn 680 Ser polymorphisms and Female infertility risk (all P values >0.05) [Figure 2]. The allele and genotype frequencies for 191756 G >A polymorphism in the FSHR gene were compared between the groups [Table 3]b. The frequencies of the FSHR genotypes at position 680 were Asn/Ser had compartavely higher frequency in infertile patients as compared to that of controls. Asn/Asn (AA) genotype in Infertility patients was 10 (09.43%) comparatively Control, 10 (06.10%) odd ratio was O1.60 (0.64-3.99) P value 0.31. The genotype frequency Asn/Ser (AG) was higher in Infertility patients 50 (47.17%) comparatively Control 82 (50.00%) odd ratio was 0.89 (0.54-1.45) P value 0.64. Genotype frequency Ser/Ser (AG) patients was 46 (43.40%) comparatively Control 72 (42.86%) odd ratio was 0.97 (0.59-1.60) P value 0.93 were more frequent in case then in case then in control subjects, however, no significant association was evident (all P values >0.05).
Figure 1: DNA sequencing results for the FSHR gene Asn680Ser polymorphisms. A. Chromatogram shows GG allele in control sample and indicate the presence of heterozygous AG allele in Infertility sample

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Figure 2: DNA sequencing results for the FSHR gene Asn680Ser polymorphisms. A. DNA sequencing of the Asn680Ser polymorphism (AA sequence altered) Homozygous is indicated by the arrow. FSHR: follicle-stimulating hormone receptor

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Analysis of Asn680Ser SNP genotypes and allele frequencies

As shown in [Table 3]a, there was an absence of statistically significant differences in genotype frequencies according to the diagnosed cause of female infertility. The infertile group was compared with the fertile control group for the Asn680Ser SNP. FSHR 191756 G >A polymorphism for A allele frequency in infertility patients was 38.22% while in control subjects were 61.78%, and G allele frequency in infertility patients was 41.77% while in control subjects was 58.23% in the Control group, respectively. Comparison of allele frequencies showed lack of statistically significant difference in allele frequencies of the FSHR 191756 G >A between infertility versus the control group. However, the observed genotype frequencies show non-significant differences in either group (P > 0.05). The allelic frequency distribution of locus 680 was consistent with the Hardy–Weinberg Equilibrium (HWE) in both groups (P > 0.05).


  Discussion Top


Understanding of genetic factors related to infertility will influence the clinical management of Infertility. Further, it will help to ensure that families with or at risk of significant inherited disorders related to infertility can be identified and referred as appropriate for a professional opinion. Furthermore, Primary care is perfectly placed to identify families at highest risk of genetic conditions for infertility. FSH Play an essential role in normal reproductive functions.[20] Due to the crucial parts of FSH on follicular growth and ovarian steroidogenesis in females mutations in the FSH receptor gene could affect reproductive ability, especially in women.[10],[21] The Molecular mechanism of the FSHR genotype for ovarian response in the physiological and therapeutic setting has been demonstrated in several studies.[22] The Genetics mechanism of FSHR variant activity is now the key to understanding follicular selection and dominance in the human and to design novel, patient-tailored therapeutic approaches, not only to ovarian stimulation, but also to infertility and, possibly, fertility preservation.[23] For example, some mutations or polymorphisms in the FSH receptor gene show an altered pattern of receptor expression on the cell surface, a previous study by Kuijper et al., 2010. Frequency distribution of polymorphisms In the FSHr gene in infertility patients of different ethnicity distribution patterns were found a significantly lower prevalence of Ser680Ser FSHR variant (10.4%).

Moreover, a significantly higher incidence of Asn680Asn variant (50.7%) in Asians, compared with Caucasians and Mediterranean.[24] A study by Jun et al. testified that the correlation Frequency of Asn/Ser, Asn/Asn, and Ser/Ser was 45.6%, 41.8%, and 12.5%, respectively.[25] These aspects should be investigated in the future by comparing the effects of the two FSHR variants in human granulosa cells.[26] Unlike other previous studies, where basal FSH and LH levels were measured on cycle day 2 or 3, we measured random levels of FSH and LH during the ovulatory period.[27]

Interestingly, we found that serum FSH and LH levels were significantly higher in anovulatory subjects who carried the Thr307Ala or Asparagine 680 Serine genotypes,[28],[29] which were consistent with the present study result. However, the present study found a critical difference among these genotypes regarding hormone profile, although a slightly higher level of FSH was observed for Asn680Ser groups. Studies reported so far indicate that mutations, polymorphisms and alternatively spliced variants in FSHR have varied effects on receptor function.


  Conclusions Top


This case-control based association study confirmed that there was an absence of a significant association of Asn680Ser polymorphisms and Female infertility risk. Variations in FSHR gene has an essential influence on ovarian function and can account for several defects of female fertility. Furthermore, studies, including prospective studies on the impact of genetic factors and environmental, on women's fertility, are needed. Broadly study the effects of FSHR polymorphisms on various reproductive health traits; the most studied rs6166 SNP should be evaluated. However, it is already clear that the relationship of FSHR Asparagine 680 Serine variant polymorphism to lower fecundity can have clinical relevance; e.g. more conservative infertility management can be suggested for women with unexplained infertility who share this genetic variation.

Acknowledgments

We want to extend our sincere gratitude to all our study participants. They have made this study possible. We also heartily thanks to our colleagues Barkha Singh, Anchal Singh, Kanchan Dubey Cytogenetic Laboratory, for their untiring efforts on this infertility Research.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

This research was sponsored by Multi-Disciplinary Research Units (MRUs) grant by ICMR and Department of Health Research.

Conflict of interest

There is no conflict of interest.



 
  References Top

1.
Zegers-Hochschild F, Adamson GD, De Mouzon J, Ishihara O, Mansour R, Nygren K, et al. The international committee for monitoring assisted reproductive technology (ICMART) and the world health organization (WHO) revised glossary on ART terminology, 2009. Hum Reprod 2009;24:2683-7.  Back to cited text no. 1
    
2.
Zahid AR. Infertility | National Health Portal Of India [Internet]. WHO-ICMART. 2016 [cited 2019 Jun 8]. p. 1-1. Available from: https://www.nhp.gov.in/disease/reproductive-system/infertility.  Back to cited text no. 2
    
3.
Gajbhiye R, Fung JN, Montgomery GW. Complex genetics of female fertility. NPJ Genomic Med 2018;3:29.  Back to cited text no. 3
    
4.
Mallepaly R, Butler PR, Herati AS, Lamb DJ. Genetic basis of male and female infertility. Monogr Hum Genet 2017;21:1-16.  Back to cited text no. 4
    
5.
Badar A, AS A, NK L. An overview on the genetic determinants of infertility. Biomed J Sci Tech Res 2018;10:001–001.  Back to cited text no. 5
    
6.
Zorrilla M, Yatsenko AN. The genetics of infertility: Current status of the field. Curr Genet Med Rep 2013;1. doi: 10.1007/s40142-013-0027-1  Back to cited text no. 6
    
7.
Woodruff TK, Shea LD. The role of the extracellular matrix in ovarian follicle development. Reprod Sci 2007;14 (8 Suppl):6-10.  Back to cited text no. 7
    
8.
Szymańska K, Kałafut J, Rivero-Müller A. The gonadotropin system, lessons from animal models and clinical cases. Minerva Ginecol 2018;70:561-87.  Back to cited text no. 8
    
9.
Zilaitiene B, Dirzauskas M, Verkauskiene R, Ostrauskas R, Gromoll J, Nieschlag E. The impact of FSH receptor polymorphism on time-to-pregnancy: A cross-sectional single-centre study. BMC Pregnancy Childbirth 2018;18:272.  Back to cited text no. 9
    
10.
He W-B, Du J, Yang X-W, Li W, Tang W-L, Dai C, et al. Novel inactivating mutations in the FSH receptor cause premature ovarian insufficiency with resistant ovary syndrome. Reprod Biomed Online 2019;38:397-406.  Back to cited text no. 10
    
11.
Ilgaz NS, Aydos OSE, Karadag A, Taspinar M, Eryilmaz OG, Sunguroglu A. Impact of follicle-stimulating hormone receptor variants in female infertility. J Assist Reprod Genet 2015;32:1659-68.  Back to cited text no. 11
    
12.
Ulloa-Aguirre A, Zariñán T, Jardón-Valadez E, Gutiérrez-Sagal R, Dias JA. Structure-function relationships of the follicle-stimulating hormone receptor. Front Endocrinol (Lausanne) 2018;9:1-17.  Back to cited text no. 12
    
13.
Wu Q, Zhang J, Zhu P, Jiang W, Liu S, Ni M, et al. The susceptibility of FSHB -211G>T and FSHR G-29A, 919A>G, 2039A>G polymorphisms to men infertility: An association study and meta-analysis. BMC Med Genet 2017;18:81. Nieschlag E. The follicle-stimulating hormone receptor : Biochemistry, Molecular Biology, Physiology, and pathophysiology. Endocr Rev 2017;18:739-73.  Back to cited text no. 13
    
14.
Simoni M, Casarini L. Mechanisms in endocrinology: Geneticsof FSH action-A 2014-and-beyond view. Eur J Endocrinol 2014;170:91-107.  Back to cited text no. 14
    
15.
Cordts EB, Christofolini DM, dos Santos AA, Bianco B, Barbosa CP. Genetic aspects of premature ovarian failure: A literature review. Arch Gynecol Obstet 2011;283:635-43.  Back to cited text no. 15
    
16.
Trevisan CM, Peluso C, Cordts EB, de Oliveira R, Christofolini DM, Barbosa CP, et al. Ala307Thr and Asn680Ser polymorphisms of FSHR gene in human reproduction outcomes. Cell Physiol Biochem 2014;34:1527-35.  Back to cited text no. 16
    
17.
Kalousová M, Levová K, Kuběna AA, Jáchymová M, Franková V, Zima T. Comparison of DNA isolation using salting-out procedure and automated isolation (MagNA system). Prep Biochem Biotechnol 2017;47:703-8.  Back to cited text no. 17
    
18.
Howe B, Umrigar A, Tsien F. Chromosome preparation from cultured cells. J Vis Exp 2014;(83):e50203.  Back to cited text no. 18
    
19.
Rama Raju G, Chavan R, Deenadayal M, Govindarajan M, Gunasheela D, Gutgutia R, et al. Luteinizing hormone and follicle stimulating hormone synergy: A review of role in controlled ovarian hyper-stimulation. J Hum Reprod Sci 2013;6:227-34.  Back to cited text no. 19
    
20.
Atabiekov I, Hobeika E, Sheikh U, El Andaloussi A, Al-Hendy A. The role of gene therapy in premature ovarian insufficiency management. Biomedicines 20181;6. doi: 10.3390/biomedicines6040102.  Back to cited text no. 20
    
21.
Stilley JAW, Segaloff DL. FSH actions and pregnancy: Looking beyond ovarian FSH receptors. Endocrinology 2018;159:4033-42.  Back to cited text no. 21
    
22.
O'Brien TJ, Kalmin MM, Harralson AF, Clark AM, Gindoff I, Simmens SJ, et al. Association between the luteinizing hormone/chorionic gonadotropin receptor (LHCGR) rs4073366 polymorphism and ovarian hyperstimulation syndrome during controlled ovarian hyperstimulation. Reprod Biol Endocrinol 2013;11:71.  Back to cited text no. 22
    
23.
Kuijper E, Blankenstein M, Luttikhof L, Roek S, Overbeek A, Hompes P, et al. Frequency distribution of polymorphisms in the FSH receptor gene in infertility patients of different ethnicity. Reprod Biomed Online 2011;22:S60-5.  Back to cited text no. 23
    
24.
Jun JK, Yoon JS, Ku S-Y, Choi YM, Hwang KR, Park SY, et al. Follicle-stimulating hormone receptor gene polymorphism and ovarian responses to controlled ovarian hyperstimulation for IVF-ET. J Hum Genet 2006;51:665-70.  Back to cited text no. 24
    
25.
Ghezelayagh Z, Sc M, Totonchi M, Ph D, Zarei-moradi S, Sc M, et al. The impact of genetic variation and gene expression level of the follicle-stimulating hormone receptor on ovarian reserve. Cell J 2016;19:620-6.  Back to cited text no. 25
    
26.
Prasad S, Gupta T, Divya A. Correlation of the Day 3 FSH/LH Ratio and LH Concentration in predicting IVF outcome. J Reprod Infertil 2013;14:23-8.  Back to cited text no. 26
    
27.
George JW, Dille EA, Heckert LL. Current concepts of follicle-stimulating hormone receptor gene regulation. Biol Reprod 2011;84:7-17.  Back to cited text no. 27
    
28.
Yan Y, Gong Z, Zhang L, Li Y, Li X, Zhu L, et al. Association of follicle-stimulating hormone receptor polymorphisms with ovarian response in Chinese women: A prospective clinical study. PLoS One 2013;8:e78138.  Back to cited text no. 28
    
29.
Laven JSE. Follicle Stimulating Hormone Receptor (FSHR) Polymorphisms and Polycystic Ovary Syndrome (PCOS). Front Endocrinol (Lausanne) 2019;10:23.  Back to cited text no. 29
    


    Figures

  [Figure 1], [Figure 2]
 
 
    Tables

  [Table 1], [Table 2], [Table 3]



 

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