Fig. 1

Flow chart for the study.design. Ultrasound Evaluation of the Male Reproductive System includes scrotal ultrasound and transrectal ultrasound. PE:Physical Examination.CBAVD: Congenital Bilateral Aplasia of the Vas Deferens;ICSI: Intracytoplasmic Sperm Injection; OA:obstructive azoospermia.CFTR: Cystic fibrosis transmembrane conductance regulator;ADGRG2: adhesion G protein-coupled receptor G2