Microsatellite Profiling of AR and RP2 Genes

One μg of genomic DNA isolated from peripheral blood was digested with FastDigest HpaII in a 20 µl reaction volume using 1 µl of restriction enzyme according to standard protocol (Thermo Fisher Scientific, Waltham, MA). Amplification of the androgen receptor (AR) microsatellites was carried out in a 20 µl reaction containing 0.1 mM of dNTP, 250 nM of each primer, 1.25 mM of MgCl₂, 2 µl of buffer, 1 U of Taq polymerase, and 50 ng of DNA or 2 µl of digested DNA, with primers and cycling conditions as previously described^{25 (link)}. Amplification of the retinitis pigmentosa 2 (RP2) gene microsatellites was performed as previously described^{26 (link)} with an input of 50 ng of DNA or 2 µl of digestion product. 5′ primers were marked with (6)-Carboxyfluorescein protein (/56-FAM; Supplementary Table S2). Genotyping was performed through a fragment length analysis (FLA), as described in the Supplemental Data 1, and analyzed with the GeneMapper™ software (Thermo Fisher Scientific, Waltham, MA). Primer sequences are stated in Supplementary Table S2.