CAG repeat length in androgen receptor gene and male infertility in Egyptian patients

Abstract

The CAG repeat and its association with infertility has been debatable. Therefore, this study was planned to assess the distribution of CAG repeat expansion in Egyptian patients and to investigate its association with male infertility. Forty-five infertile men were eligible for the study in addition to 20 aged-matched fertile males as control. Semen analysis, scrotal sonography, assay of serum testosterone, follicle-stimulating hormone (FSH) and luteinising hormone (LH), and determination of the CAG repeat number within exon 1 of the androgen receptor (AR) gene were carried out. Statistically significant difference was found between infertile and control groups regarding sperm count, sperm motility, serum FSH level and CAG repeats (P < 0.05); statistically insignificant difference for the CAG repeats (P = 1.0) was found between oligozoospermic and asthenospermic groups; negative correlation was found between CAG repeat length and sperm count, and a positive correlation was found between CAG repeat length and serum FSH (P < 0.05). Our results validate the concept that long stretches of CAG repeat may be associated with lower AR function with derangement of sperm production, and this may contribute to male infertility in Egyptian men.

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.…”

“…Data of azoospermic group were provided by 19 reports. 12–24,27,28,33,37,42,45 Six reports 13,17,25,32,61,62 provided data of oligospermic group without further stratification. Some reports 12,14–16,18-21,23,24 classify oligospermic group according to sperm concentration.…”

Revisiting the relationships of 2D:4D with androgen receptor (AR) gene and current testosterone levels: Replication study and meta‐analyses

“…Relationship between the length of AR (CAG)n and current testosterone levels is somewhat inconsistent referring to the previous studies in males: The four studies indicate that the length is positively correlated with the levels (De Naeyer et al, ; Ma et al, ; Manuck et al, ; Stanworth, Kapoor, Channer, & Jones, ); another study, however, demonstrates a significant negative correlation between them (Mosaad, Shahin, Elkholy, Mosbah, & Badawy, ); and another 15 studies report there is no a significant correlation between them at all (Aluja et al, ; Durdiaková et al, ; Durdiaková et al, ; Eisenegger, Kumsta, Naef, Gromoll, & Heinrichs, ; Gettler et al, ; Goutou, Sakka, Stakias, Stefanidis, & Koukoulis, ; Hampson & Sankar, ; Kubranska et al, ; Lapauw, Goemaere, Crabbe, Kaufman, & Ruige, ; Nowak, Diamond, Land, & Moffat, ; Ryan et al, ; Sankar & Hampson, ; Schneider et al, ; Schneider, Zitzmann, Gromoll, Ladwig, & Berger, ; Stiger et al, ). Regarding the same relationship analyzed by previous studies for females, two studies indicate the length is positively correlated with the levels (Peng et al, ; Skrgatic, Baldani, Cerne, Ferk, & Gersak, ); such relationship, however, is significantly negative (Brum et al, ; Jaaskelainen et al, ); or not significant (Durdiaková et al, ; Jaaskelainen, Korhonen, Voutilainen, Hippelainen, & Heinonen, ; Nowak et al, ).…”

Male reproductive health and prostate cancer risk

“…The authors reported a negative correlation between CAG repeat length and sperm count thereby validating the concept that long stretches of CAG repeat may be associated with derangement of sperm production, presumably via decreased AR function. [43–47] Data associating androgen receptor CAG repeats with prostate cancer have been inconsistent but several studies have linked variation in CAG repeat length to clinically aggressive CaP. [48–52]…”