BRD2 and Sertoli Cell-Only Syndrome: Significantly higher frequencies of microdeletions have been reported in the setting of histologically-confirmed Sertoli cell only syndrome (SCOS), Klinefilter syndrome, and among patients with chromosomal abnormalities, variocele and cryptorchidism, and idiopathic azoospermia accompanied by elevated serum follicle-stimulating hormone (FSH) levels [23,44,47,51,56,57].