The impact of androgen receptor polymorphism and parental ethnicity on semen quality in young men from Latvia

Abstract

Recent studies on young men from the general population have demonstrated geographic and ethnic differences in semen quality. The aim of this study was to investigate whether reported ethnic differences in semen quality might be associated with the maternally derived CAG and GGN polymorphisms in the androgen receptor gene or paternal ethnicity. In total 114 military conscripts from Latvia were included in the study. Information on maternal and parental ethnicity was collected by questionnaires. CAG and GGN repeats were analysed by direct sequencing of leukocyte DNA. Men with Latvian mothers (n = 83) had marginally shorter CAG repeat length (21.6 +/- 2.9) as compared with those with non-Latvian mothers (22.9 +/- 3.2, n = 31), not reaching statistical significance (p = 0.053). Sperm concentration did not differ significantly between these two groups (76 +/- 59 and 70 +/- 52, p = 0.9 respectively). In contrast, significantly higher sperm concentration and total sperm count were found in men with Latvian fathers (n = 77) as compared with men with non-Latvian fathers (n = 37) (80 +/- 61 vs. 62 +/- 48, p = 0.035, for sperm concentration and 225.7 +/- 209 vs. 158.4 +/- 134.4, p = 0.002, for total sperm count respectively). CAG repeat length did not correlate with any semen parameters in the whole population. However, GGN repeat length correlated with semen volume: men with GGN > 23 presented with higher semen volume (3.2 +/- 2.1) as compared with men with GGN = 23 (2.6 +/- 1.3, p = 0.04) or GGN < 23 (2.0 +/- 1.2, p = 0.006). We conclude that GGN repeat length has an impact on semen volume, whereas differences in sperm numbers are associated with the paternal ethnicity.

No Correlation between Androgen Receptor CAG and GGN Repeat Length and the Degree of Genital Virilization in Females with 21-Hydroxylase Deficiency

“…In males, a GGn repeat length greater than 24 was reported to be associated with poor semen quality (27). In contrast, other studies found a decreased sperm volume in males with an nGGn less than 23 but no influence of the GGn repeat length on sperm count (28,29). Moreover, a large investigation on Indian males (n ϭ 595) found no difference of GGn length between fertile and infertile subjects (30); however, a significant difference of GGn repeat length in patients with penile hypospadias and cryptorchidism was reported (31).…”

Sperm Quality Decline Among Men Below 60 Years of Age Undergoing IVF or ICSI Treatment

“…This could not be explained by differences in age, BMI, smoking, and alcohol use between the groups, suggesting that these migrant men may have adapted to the Dutch lifestyle. It is possible that several unmeasured lifestyle factors, such as diet, occupational hazards, exercise, psychosocial stress, genetic factors, and overall health may also play a role (Erenpreiss et al, 2008). It has been reported that an adequate intake of unsaturated fatty acids present in fish improves sperm quality.…”

“…Besides aging and lifestyle factors, genetic variations also affect spermatogenesis (Giwercman et al, 2006; Erenpreiss et al, 2008). This is supported by the reported ethnic as well as geographic differences in sperm quality.…”

“…This is supported by the reported ethnic as well as geographic differences in sperm quality. Genetic variations in the Y chromosome, CAG repeats of the androgen receptor, and endocrine and metabolic pathways also contribute to differences in susceptibility to adverse environmental exposures and as such influence sperm quality (Giwercman et al, 2006; Erenpreiss et al, 2008). The effects of genetic influences become particularly clear from the studies performed in the Baltic countries, in which despite a similar lifestyle a higher sperm concentration was reported in Finland, Estonia, Lithuania, and Latvia than in Denmark and Norway (Jorgensen et al, 2002; Tsarev et al, 2005).…”

Idiopathic Infertility as a Feature of Genome Instability

“…A variable MSI-related region is found in the androgen receptor ( AR ) gene [ 42 , 43 ]. The AR is a hormonal transcription factor mediating the physiologic and pathophysiologic effects of androgens, such as sexual differentiation and prostate development.…”