CAG repeat length in an infertile male population of Irish origin

Abstract

The androgen receptor (AR) gene, located on the X chromosome, is an important regulator of human spermatogenesis. In the past decade, the link between the CAG polyglutamine tract, situated on exon one of the AR gene, and reduced spermatogenesis has become a controversial one. Alterations in the length of the CAG polyglutamine tract have been associated with prostate cancer at a reduced intrinsic length and neuromuscular diseases at a CAG repeat length of > or = 40. Minimal intermediate increases have been linked with depressed spermatogenesis in infertile males. Asian and Australian groups have published an association between increased CAG repeat length and reduced spermatogenesis while many European studies have found no such association. The aim of this study was to document the association between increased CAG repeat length and reduced spermatogenesis in a group of Irish infertile males and controls known to have fathered at least one child. The study employed the ABI 377 DNA sequencer to size the CAG repeat region of exon one of the AR gene in each group. Statistical analysis revealed no actual link between the length of the CAG tract and a reduction of spermatogenesis in a cohort of infertile patients (n = 66) of Irish ethnic origin when compared to a fertile control group (n = 77) (p = 0.599).

Genetic Association Between Androgen Receptor Gene CAG Repeat Length Polymorphism and Male Infertility

“…Eventually, 41 English and 3 Chinese reports meet all criteria of inclusion. 1,12–28,31–37,39,40,42–49,51–53,56–58,61,62,64 The characteristics of the selected studies are shown in Table 1. One report 25 included studies on 2 different ethnic groups, so we consider it as 2 separate studies.…”

Androgen receptor-CAG repeats in infertile Egyptian men

“…In Sweden, Ruhayel et al (2004) reported that the distributions of CAG did not differ significantly between patients and controls. In Ireland, Lavery et al (2005) reported no actual link between the length of CAG and reduced spermatogenesis in infertile men compared with fertile controls. In Turkey, Tufan et al (2005) reported nonsignificant relation between CAG repeats and idiopathic impaired sperm production.…”

Impact of CAG repeat length in the androgen receptor gene on male infertility – a meta-analysis

“…One hundred and forty-five publications were excluded because they were not associated with male infertility or CAG repeat, were repeat articles, or were meta-analyses without case controls. Finally, 39 publications (Asatiani et al, 2003;Badran et al, 2009;Canale et al, 2005;Casella et al, 2001;Cram et al, 2000;Dadze et al, 2000;Dakouane-Giudicelli et al, 2006;Dhillon and Husain, 2003;Erasmuson et al, 2003;Ferlin et al, 2004;Hadjkacem et al, 2004;Han et al, 2013;Hiort et al, 2000;Katagiri et al, 2006;Khatami et al, 2015;Lavery et al, 2005;Lu et al, 2006;Lund et al, 2003;Madgar et al, 2002;Martinez-Garza et al, 2008;Mengual et al, 2003;Mifsud et al, 2001a;Milatiner et al, 2004;Mosaad et al, 2012;Mostafa et al, 2012;Pan et al, 2002;Patrizio et al, 2001;Peterlin et al, 2007;Rajpert-De Meyts et al, 2002;Ruhayel et al, 2004;Saare et al, 2008;Sasagawa et al, 2001;Thangaraj et al, 2002;Tse et al, 2003;Tufan et al, 2005;von Eckardstein et al, 2001;Van Golde et al, 2002;Wallerand et al, 2001;…”

“…Three additional studies (Akinloye et al, 2009;Castro-Nallar et al, 2010;Delli Muti et al, 2014) were included to calculate OR. Twenty-eight publications (Akinloye et al, 2009;Asatiani et al, 2003;Canale et al, 2005;Castro-Nallar et al, 2010;Dadze et al, 2000;Delli Muti et al, 2014;Ferlin et al, 2004;Hadjkacem et al, 2004;Han et al, 2013;Katagiri et al, 2006;Khatami et al, 2015;Lavery et al, 2005;Lu et al, 2006;Lund et al, 2003;Martinez-Garza et al, 2008;Mengual et al, 2003;Pan et al, 2002;Peterlin et al, 2007;Rajpert-De Meyts et al, 2002;Ruhayel et al, 2004;Saare et al, 2008;Sasagawa et al, 2001;Thangaraj et al, 2002;Tse et al, 2003;Tufan et al, 2005;von Eckardstein et al, 2001;Van Golde et al, 2002;Xie et al, 2014) with 29 case-control studies and one publication (Mifsud et al, 2001b) with two case-control studies were included for further analysis. Supplementary Table S1 shows studies used for subgroup analysis.…”