Testosterone (T) is a central androgenic hormone, and sex hormone-binding globulin (SHBG) is the major determinant of its bioactivity. There are no acknowledged genetic variants with clear-cut clinica Show more
Testosterone (T) is a central androgenic hormone, and sex hormone-binding globulin (SHBG) is the major determinant of its bioactivity. There are no acknowledged genetic variants with clear-cut clinical implications, modulating T levels in men. To confirm genetic associations of top loci ( Groups differing in general and reproductive parameters: young men (n = 540; 19.3 ± 1.8 years), severe idiopathic male infertility patients (n = 641; 31.6 ± 6.0 years), and male partners of pregnant women (n = 324; 31.9 ± 6.6 years). All patients were recruited at the Andrology Centre, Tartu University Hospital, Estonia. Genetic associations with reproductive hormones, testicular and sperm parameters (linear regression, additive model); intergroup allele/genotype distribution comparisons. Associations with serum SHBG levels were robust for Claims were replicated and additional associations were detected for four of seven tested GWAS top loci. Perspective clinical investigations of these variants are hypotestosteronemia among aging men and pharmacogenetics of hormone replacement therapy. Show less