The World Health Organization (WHO) estimates that 10.0-15.0% of couples in the Western World develop issues regarding fertility. In addition, we can estimate that nearly 50.0% of couples with infertility have an underlying genetic abnormality [1].
Mutation in the
Although we cannot establish the phenotype only from the genetic profile, there are certain associations between the two. Patients with a detected mutation in the
Reduced fertility in female patients with CAH is often associated with excessive androgen levels. Adrenal androgens directly inhibit aromatase activity in granulosa cells of the ovary, thus indirectly hindering foliculogenesis. The high androgen levels result in gonadotropin-releasing hormone (GnRH), inhibition, leading to anovulation [10,11].
Thankfully, with glucocorticoid replacement therapy of patients with classical CAH, females mature into adults, so the focus has shifted to infertility treatment [2]. These patients suffer not only from salt wasting, they also have concomitant excessive androgens, excessive progesterone, post-reconstructive surgery states, PCOS, ovarian adrenal rest tumors and various psychosexual factors [1,5,11-14].
In our study, we presumed that the mutations c.290-13A/C>G, p.I172N, p.P30L and p.V281L in the
Our study was a retrospective study and included 838 probands representing two different groups: couples with UFP and HCs. Couples with UFP (
All samples were from individuals of Caucasian origin who were residents of different geographical areas of Slovenia. Informed consent was obtained from all participating individuals and ethical approval was granted prior to conducting the study.
For female probands, the following clinical and biochemical parameters were determined: the concentration of prolactin in serum (nmol/L), the concentration of dihydroepiandrosterone in serum (nmol/L), the concentration of free testosterone in serum (nmol/L), the concentration of testosterone in serum (nmol/L), concentration of Anti-Muller hormone levels in serum (nmol/L), body mass index (BMI), the presence of a thyroid disease, the presence of an autoimmune disease, the presence of PCOS.
The follicular phase of the menstrual cycle was determined: the concentration of follicle-stimulating hormone in serum (nmol/L), the concentration of luteinizing hormone in serum (nmol/L), the concentration of 1,2-estradiol in the serum (nmol/L). In the luteal phase of the menstrual cycle, the concentration of progesterone in the serum (nmol/L) was determined. Basic laboratory parameters of female probands are given in Table 1.
Ages, mean ages and age ranges of the male and female probands.
Total | Males | Females | |
---|---|---|---|
638 | 319 | 319 | |
Mean age | 32.9 | 33.8 | 32.0 |
Age range (years) | 21-44 | 23-44 | 21-44 |
Peripheral venous blood was collected in standard collection vacutainers containing EDTA as anticoagulant. Genomic DNA was extracted from blood leukocytes with a simple salting-out method [15]. All DNA samples were screened for the four most common mutations (p.P30L in exon 1, c.290-13A/ C>G in intron 2, p.I172N in exon 4 and p.V281L in exon 7) in the
For statistical analysis, the Statistical Package for the Social Science (SPSS), version 21 software program (IBM Corporation, Armonk, NY, USA), was used. Comparison between the means was done by non parametric tests. The results were expressed as an arithmetic mean ± standard deviation (SD). The relations between variables were analyzed by the analysis of variance (ANOVA) test. The distribution of the mutations was compared using the χ2 test;
We analyzed 319 couples, a total of 638 individuals (average age 32.9 years, median age 33 years), 319 females (average and median age 32 years, range 21-44 years) and 319 males (average age 33.8 years, median age 34 years, range 23-44 years). The control group included 200 healthy blood donors (average and median age 43 years), 100 females (average and median age 42 years, range 27-66 years) and 100 males (average and median age 44 years, range 21-71 years) (Table 1).
For female probands, significant clinical parameters, biochemical parameters and the simultaneous presence of: a thyroid disease, increased BMI, an autoimmune disease, PCOS, conditions related to the concentration of sex hormones and conditions related to the concentration of progesterone, were determined. Number and proportions of female probands with the deviation of laboratory parameters from the reference value and the presence of the clinical indicators are presented in Table 2.
Number and percentage of female probands with the deviation of laboratory parameters from the reference value and the presence of the clinical indicators.
Parameters/Clinical Indicator | % | |
---|---|---|
A thyroid disease | 19 | 6.1 |
Hor | 40 | 12.5 |
Est | 22 | 6.9 |
Prog | 3 | 0.9 |
An autoimmune disease | 6 | 1.9 |
PCOS | 18 | 5.6 |
BMI | 44 | 13.8 |
Hor: deviation of estrogens and/or 17-OHP and/or testosterone in serum; Est: deviation of estrogens in serum; Prog: deviation of 17-OHP in serum. Autoimune disease: celiac disease; Chron’s disease; psoriasis; rheumatoid arthritis; lupus and ulcerative colitis. PCOS: polycystic ovary syndrome; BMI: body mass index.
From Table 2, we can see that in the study group the proportion of females with the irregularities within the concentration of hormones (12.5%) stand out. At the same time, the smallest proportion belongs to the females with the deviation of 17-OHP in serum (0.9%). The c.290-13A/ C>G, p.I172N, p.P30L and p.V281L mutation frequencies were compared between probands and controls. There were no significant differences in mutation frequencies for all four mutations (χ2 = 2.167,
The c.290-13A/C>G, p.I172N, p.P30L and p.V281L mutation frequencies in couples with unexplained fertility problems and controls.
Mutations | Probands ( | Controls ( | χ2 | |
---|---|---|---|---|
c.290-13A/C>G | 4 (0.6) | 1 (0.5) | 0.043 | 0.836 |
p.I172N | 4 (0.6) | 3 (1.5) | 1.389 | 0.239 |
p.P30L | 0 (0.0) | 1 (0.5) | 3.183 | 0.074 |
p.V281L | 1 (0.2) | 1 (0.5) | 0.749 | 0.387 |
Total | 9 (1.4) | 6 (3.0) | 2.167 | 0.141 |
Additionally, the c.290-13A/C>G, p.I172N, p.P30L and p.V281L mutation frequencies were compared between male and female probands. There were no significant differences in mutation frequencies for all four mutations (χ2 = 2.254,
Number and percentage of mutations discovered in the male and females probands.
Males | Females | χ2 | ||||
---|---|---|---|---|---|---|
Mutations | % | % | ||||
c.290-13A/C>G | 2 | 0.6 | 2 | 0.6 | 0.043 | 0.979 |
p.I172N | 2 | 0.6 | 2 | 0.6 | 1.389 | 0.499 |
p.P30L | 0 | 0.0 | 0 | 0.0 | 0.000 | |
p.V281L | 1 | 0.3 | 0 | 0.0 | 1.405 | 0.495 |
Total | 5 | 1.6 | 4 | 1.3 | 2.254 | 0.324 |
The possible impact of most common mutations in the
Comparison of clinical parameters of the entire group of female probands with the c.290-13A/C>G, p.I172N, p.P30L and p.V281L mutations and female probands without the c.290-13A/C>G, p.I172N, p.P30L and p.V281L mutations.
Clinical Parameters | c.290-13A/C>G (χ2; | p.I172N (χ2; | p.P30L (χ2; | p.V281L (χ2; |
---|---|---|---|---|
A thyroid disease | 0.257; 0.613 | 0.257; 0.613 | ‒; | 0.064; 0.801 |
Hor | 0.581; 0.446 | 0.581; 0.446 | ‒; | 6.997; 0.008 |
Est | 0.300; 0.584 | 0.300; 0.584 | ‒; | 0.074; 0.785 |
Prog | 0.038; 0.845 | 0.038; 0.845 | ‒; | 0.010; 0.922 |
An autoimmune disease | 0.078; 0.781 | 0.078; 0.781 | ‒; | 0.019; 0.890 |
PCOS | 0.242; 0.623 | 0.242; 0.623 | ‒; | 16.775; 0.000 |
BMI | 0.648; 0.421 | 0.648; 0.421 | ‒; | 0.161; 0.689 |
Hor: deviation of estrogens and/or 17-OHP and/or testosterone in serum; Est: deviation of estrogens in serum; Prog: deviation of 17-OHP progesterone in serum. Autoimune diseases: celiac disease; Chron’s disease; psoriasis; rheumatoid arthritis; lupus and ulcerative colitis. PCOS: polycystic ovary syndrome; BMI: body mass index.
We found a statistically significant association between clinical indicator for irregularities within the concentration of hormones and the p.V281L mutation (χ2 = 6.997,
In our research, we determined the frequency of the c.290-13A/C>G, p.I172N, p.P30L and p.V281 mutations in couples with conceiving problems comparing them with a healthy control group. We did not observe any statistical differences between frequency of heterozygous carriers in infertile couples and HCs. Although we did not find any statistically important association, we cannot exclude the importance of the aforementioned mutations in infertility. We attribute it to an insufficient number of test subjects and controls. Also, we cannot draw an indefinite conclusion, as the presence of mutations in the
In female test subjects, we examined the hormonal profiles during stages of the menstrual cycle and determined concomitant diagnosed illnesses from available medical documentation. We did not find any statistically significant association between hormonal deviations, concomitant illnesses and mutation frequency. However, we can conclude that the presence of a single mutation in the
In general, fertility in people with CAH ranges from normal to severely impaired, as Reichman
Çakir
We also studied the association between mutations in CAH and most frequently found concomitant illnesses. We did not find any association between female test subjects and the frequency of associated illnesses. Deckx
The
Thyroid disorders are closely associated with infertility. They not only affect female fertility but also hinder most of the human organs [27,28]. Sinha
On the other hand, we found an association between the p.V281L mutation in the
Surprisingly, we did not find a firm association between mutations and deviance in hormonal profiles. Of course, our results do not disprove that the c.290-13A/ C>G, p.I172N, p.P30L and p.V281L mutations in the
Whether it is necessary to enroll all couples diagnosed with infertility in genetic counseling, is still debatable. Many studies confirm the necessity of such a protocol, as there is a confirmed higher incidence of gene mutations among these couples [32]. Conversely, Papanikolaou
In conclusion, does an early diagnosis of CAH essentially reduce the consequence of CAH? Moreover, should we be actively screening the population for mutations in the
The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.