CHROMOSOMAL ABNORMALITIES IN SEVERE OLIGOZOOSPERMIC INFERTILE MALES

CHROMOSOMAL ABNORMALITIES IN SEVERE OLIGOZOOSPERMIC INFERTILE MALES

By

Ali Ramadan Rabie¹, Ahmad Kamel Seddeik Abdel-Hameed^1,2, Mahmoud Fawzy Abdel Hamid³, Hesham Fayek Ismail Kayed⁴

and Ahmed Mohamed Maher Abdel Rahman⁵

¹Department of Dermatology, Venereology and Andrology, Al-Azhar University Faculty of Medicine; ²Assisted reproduction unit, the International Islamic Centre for Population Studies and Research (IICPSR), Al-Azhar University; ³Department of Dermatology, Venereology, ⁴Department of Human Cytogenetics, National Research Centre;

⁵Misr University for Science and Technology

ABSTRACT

Background: Genetic abnormalities account for 15-30% of infertility in males.Chromosomal abnormalities alone are responsible for approximately 5% of male infertility.

Objective: Determining the prevalence and type of chromosomal abnormalities in a group of infertile Egyptian males with severe oligozoospermia.

Patients and methods: Karyotyping was performed on peripheral blood lymphocyte samples of 60 infertile Egyptian men with severe oligozoospermia (sperm count ≤ 5×10⁶/ml)during the period between April 2015 and June 2016.

Results: Out of the 60 patients studied, chromosomal abnormalities were identified in 5 (8.33%) patients. All the identified abnormalities were structural autosomal abnormalities.

Conclusion: These results highlighted the importance of genetic screening and counselling for males with severe oligozoospermia before scheduling them for any of the assisted reproduction techniques.

INTRODUCTION

     According to the International Committee for Monitoring Assisted Reproductive Technology (ICMART), and World Health Organization (WHO), infertility is a disease of the reproductive system defined by the failure to achieve a clinical pregnancy after12 months or more of regular unprotected sexual intercourse (Gurunath et al., 2011). It is a global problem affecting about 15% of couples worldwide(Jungwirth et al., 2012). Male factor alone is responsible for 20-30% of infertile couples and contributes to another 30-40% of cases. Overall, genetic abnormalities account for 15-30% of infertility in males. Chromosomal abnormalities alone are responsible for approximately 5% of male infertility (O'Flynn O'Brien et al., 2010). Many reports throughout the world showed increased prevalence of chromosomal abnormalities, structural and numerical, in males with oligozoospermia or azoospermia, and that the prevalence is higher in oligozoospermia compared to azoospermia (Balkan et al., 2008; Kosar et al., 2010; Mafra et al., 2011; Fu et al., 2012; Ghorbel et al., 2012 and Pylyp et al., 2013).

    With the introduction of intracyto-plasmic sperm injection (ICSI), it became possible for men with severe oligozoospermia to father children of their own. However, there is a concern of probable transmission of the chromosomal abnormalities, if found, to the offspring (Dul et al., 2012).

     In spite of the recommendations to do karyotyping in all males with non-obstructive azoospermia or a sperm count less than 5 million per ml, this step may be bypassed for patients with severe oligozoospermia intended for ICSI.

    Previous reports in Egypt (Nazmy, 2008; Mekkawy et al., 2012 and Younan et al, 2015) addressed the problem in both partners (males and females) and in azoospermic as well as oligozoospermic patients. No previous studies in Egypt specifically studied the chromosomal abnormalities in severe oligozoospermic patients which are more likely to bypass the genetic screening before implementa-tion of ICSI.

     The aim of the current study was to determine the prevalence and type of chromosomal abnormalities in a group of infertile Egyptian males with severe oligozoospermia.

PATIENTS AND METHODS

     Sixty Egyptian men suffering from primary infertility with severe oligozo-ospermia (sperm count ≤ 5×10⁶/ml) were enrolled into the current study. Patients were recruited consecutively from the attendants of the andrology clinic, assisted reproduction unit of the International Islamic Centre for Population Studies and Research (IICPSR), Al-Azhar University (Cairo, Egypt) during the period between April 2015 and June 2016. All patients underwent thorough history taking, complete physical examination, semen analysis according to the 2010 laboratory manual of the World Health Organization recommendations(Akgul et al., 2009), hormonal profile assessment including FSH, LH and total testosterone (T) and karyotyping. Patients with any possible cause of poor semen parameters such as varicocele, previous exposure to gonadotoxins or obstruction were excluded from the study. The study protocol was approved by the research ethics committee of the Faculty of medicine, Al-Azhar University. The nature of the study was explained to all participants who gave an informed consent.

    Chromosomal analysis was performed on peripheral lymphocyte cultures using standard methods. At least 50banded metaphase spreads were counted, 25 analysed and 12karyotyped using the imaging system.

Statistical analysis: Descriptive statistics were used to describe patients’ characteristics which were presented as mean ± SD. Student’s t-test was used to compare between patients with normal and abnormal karyotype results.

RESULTS

     Sixty infertile men with severe oligozoospermia (sperm count ≤ 5×10⁶/ml) were studied. Patients aged between 25 and 50 years (mean ± SD = 35.08 ± 7.64 year). Duration of infertility, sperm count and hormonal profile of all patients were summarized in table (1).

     Chromosomal abnormalities were identified in 5 out of the 60 patients (8.33%). All the identified abnormalities were structural autosomal abnormalities including 1 Robertsonian translocation and 4 reciprocal translocations (Table 2 and Fig 1-5).

    There was no statistically-significant difference between patients with normal and abnormal karyotype results regarding age, duration of infertility, and levels of FSH, LH and Testosterone (T). However, there was a statistically-significant difference (P = 0.04) between the two groups regarding sperm count (Table 3).

Table (1): Age, duration of infertility, sperm count and hormonal profile of the study population. Data are presented as range (mean ± SD)..

Table (2): Chromosomal abnormalities in the studied group.

Table (3): Comparison between patients with normal and abnormal karyotype results using student’s t-test. Data are presented as range (mean ± SD).

Figure (1): Karyotyping in patient no. (13) showing 45,XY;der(13;14)(q10;q10).

Figure (2): Karyotyping in patient no. (29) showing 46,XY,t(1;3)(q21;q23).

Figure (3): Karyotyping in patient no. (48) showing 46,XY,der(14)t(4;14)(q10;q10).

Figure (4): Karyotyping in patient no. (52) showing 46,XY,t(5;16)(q31;q24).

Figure (5): Karyotyping in patient no. (59) showing 46,XY,t(9;13)(q34;q14).

DISCUSSION

    Among the diverse causes of poor semen parameters and male infertility, genetic defects play a significant role(Zorrilla and Yatsenko, 2013). Spermatogenesis is controlled by a number of genes located on Y chromosome and autosomes as well as in the mitochondrial DNA. The products of these genes function at different stages of spermatogenesis (Han et al., 2013).

    In the present study, autosomal chromosomal anomalies were detected in 8.33% (5/60) of patients. Reports from different parts of the world showed variable prevalences of chromosomal abnormalities in (severe) oligozoospermia patients ranging from 0% to 18.4%(Balkan et al., 2008; Martinez-Garza et al., 2008; Akgul et al., 2009; Kosar et al., 2010; Han et al., 2013; Pylyp et al., 2013). These variations could be attributed to the different genetic background of the studied populations and the severity of the oligozoospermia.

    In the current study, all the anomalies detected were balanced reciprocal translocations and no sex chromosome anomalies were detected.

    The absence of sex chromosome abnormalities is compatible with previous observations that abnormalities in sex chromosomes are mainly associated with severe spermatogenic failure and azoospermia, while balanced autosomal anomalies usually result in oligozoosper-mia (Kumtepe et al., 2009).

    Balanced autosomal translocations may cause oligozoospermia through inter-ference with normal chromosome pairing and segregation at meiosis I or through dysregulation of potential genes involved in male gametogenesis at chromosome breakpoints (Al-Achkar et al., 2013 and Alhalabi et al., 2013).

    Males with severe oligozoospermia are now able to father children of their own using ICSI but they may pass on the chromosomal abnormalities, if present, to their offspring. It is, therefore, important to do genetic studies for those patients before ICSI procedures. However, the availability of sperms in this group of patients (unlike azoospermic patients) may encourage some to bypass this step and go directly for ICSI.

    In conclusion, the results of the current study showed that chromosomal anomalies are common in severely oligozoospermic patients and they should undergo genetic screening and counselling prior to ICSI procedures.

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