Analiza mikrodelecija Y hromozoma i mutacija CFTR gena kao genetskih markera infertiliteta kod muškaraca u Srbiji

Abstract

Uvod/Cilj. Poremećena plodnost muškog partnera je glavni uzrok infertiliteta kod polovine neplodnih parova. Na genetskom nivou infertilitet kod muškaraca mogu uzrokovati hromozomske aberacije ili genske mutacije. U ovoj studiji analizirano je prisustvo i tip mikrodelecija Y hromozoma i mutacija u genu za regulator transmembranske provodljivosti u cističnoj fibrozi (CFTR) kao genetska osnova infertiliteta kod muškaraca u Srbiji. Cilj studije je bio da se analiziraju mutacije u CFTR genu i mikrodelecije Y hromozoma, kao potencijalni uzroci infertiliteta kod muškaraca u Srbiji, kao i da se testira hipoteza da su CFTR mutacije kod infertilnih muškaraca predominantno locirane u nekoliko poslednjih egzona. Metode. Studija je obuhvatila 33 muškarca sa oligo ili azospermijom. Detekcija mikrodelecija Y hromozoma u regionu faktora azospermije (AZF) vršena je pomoću multipleks PCR metode. Pretraživanje CFTR gena vršeno je metodom elektroforeze u gelu sa gradijentom denaturišućeg agensa (DGGE). Rezultati. Delecije Y hromozoma su detektovane kod četiri bolesnika, predominantno u AZFc regionu (četiri od ukupno šest). Mutacije u CFTR genu su detektovane na osam od 66 analizovanih hromozoma infertilnih muškaraca. Najčešće detektovana CFTR mutacija je F508del (šest od osam). Zaključak. Ova studija je potvrdila da mikrodelecije Y hromozoma i mutacije u CFTR genu igraju važnu ulogu u etiologiji infertiliteta kod muškaraca u Srbiji. Genetsko testiranje koje obuhvata detekciju mikrodelecija Y hromozoma i mutacija u CFTR genu uvedeno je u rutinsku dijagnostičku praksu i ponuđeno je parovima koji pristupaju asistiranoj reprodukciji. S obzirom da tip mikrodelecija Y hromozoma i tip mutacija u CFTR genu imaju prognostički značaj, preporuka je da se genotipizacija AZF regiona i CFTR gena ne vrši samo kod bolesnika sa umanjenim kvalitetom sperme pre pristupanja asistiranoj reprodukciji, već i u svrhe preimplantacione i prenatalne dijagnostike kod parova kod kojih je uspešno izvršena in vitro fertilizacija.

Background/Aim. Impaired fertility of a male partner is the main cause of infertility in up to one half of all infertile couples. At the genetic level, male infertility can be caused by chromosome aberrations or gene mutations. The presence and types of Y chromosome microdeletions and cystic fybrosis transmembrane conductance regulator (CFTR) gene mutations as genetic cause of male infertility was tested in Serbian men. The aim of this study was to analyze CFTR gene mutations and Y chromosome microdelations as potential causes of male infertility in Serbian patients, as well as to test the hypothesis that CFTR mutations in infertile men are predominantly located in the several last exons of the gene. Methods. This study has encompassed 33 men with oligo- or azoospermia. The screening for Y chromosome microdeletions in the azoospermia factor (AZF) region was performed by multiplex PCR analysis. The screening of the CFTR gene was performed by denaturing gradient gel electrophoresis (DGGE) method. Results. Deletions on Y chromosome were detected in four patients, predominantly in AZFc region (four of total six deletions). Mutations in the CFTR gene were detected on eight out of 66 analyzed chromosomes of infertile men. The most common mutation was F508del (six of total eight mutations). Conclusion. This study confirmed that both Y chromosome microdeletions and CFTR gene mutations played important role in etiology of male infertility in Serbian infertile men. Genetic testing for Y chromosome microdeletions and CFTR gene mutations has been introduced in routine diagnostics and offered to couples undergoing assisted reproduction techniques. Considering that both the type of Y chromosome microdeletion and the type of CFTR mutation have a prognostic value, it is recommended that AZF and CFTR genotyping should not only be performed in patients with reduced sperm quality before undergoing assisted reproduction, but also for the purpose of preimplantation and prenatal diagnostics in couples in which in vitro fertilization has been performed successfully.