Developmental differences in cell-specific AR expression in LE/orl fetal gubernacula may contribute to the dysmorphism and aberrant function that underlies cryptorchidism susceptibility in this strain.
The aim of this meta-analysis was to analyse the potential effects of AR CAG and/or GGN repeat polymorphism on CO. Studies were independently appraised by two investigators on PubMed, Web of Science, EBSCO databases and Foreign Medical Retrieval System.
The presence of AR in the epithelial cells of AT in patients with retractile testicle and its absence in patients with congenital undescended testis can be a possible cause of the effectiveness of hormonal treatment in retractile testis and its inefficacy in patients with congenital undescended testis.
Androgens are essential for testicular descent, and functional genetic polymorphisms in the androgen receptor gene (AR) are postulated to influence cryptorchidism risk.
For example, among endocrine-related-diseases, the PolyGln size has been proposed to be associated to prostate cancer susceptibility, hirsutism, male infertility, cryptorchidism (in conjunction with polyglycine stretches polymorphism), etc.; the molecular mechanisms of these alterations are thought to involve a modulation of AR transcriptional competence, which inversely correlates with the PolyGln length.
Mutations in the gene for insulin-like factor 3 and its receptor and in the androgen receptor gene have been recognized as causes of cryptorchidism in some cases, but some chromosomal alterations, above all the Klinefelter syndrome, are also frequently involved.
Androgen receptor mRNA transcript levels were approximately 10 times lower in cremaster muscles of boys with descended testis compared with those in boys with undescended testis.
Although further studies are needed to elucidate the possible role of specific CAG/GGC combinations as a causative factor, these data suggest a possible association between androgen receptor gene polymorphisms and cryptorchidism.
Although sufficient androgen receptor (AR) function is crucial for normal male sexual differentiation, single-point mutations in the AR gene are infrequent in the two most common male congenital malformations, hypospadias and cryptorchidism.
Mutations of the androgen receptor gene in the hormone and DNA binding domains of the protein appear to be an unlikely cause of isolated cryptorchidism.