In 1% of men with infertility, obstructive azoospermia (OA) may occur in congenital absence of the vas (CAVD) or idiopathic obstructive azoospermia . Many studies have shown that the pathogenic genes of OA are CFTR and ADGRG2 genes, and the inheritance mode is autosomal recessive. Although the conventional assisted reproductive technology(PESA/TESA) can help these patients have children, male patients who carry mutations of the disease-causing genes (CFTR and ADGRG2) will also pass on their mutations to the next generation, which will increase the risk of male offspring infertility. Therefore, genetic detection of CFTR and ADGRG2 genes is very necessary for CAVD patients before assisted reproduction. Genetic diagnosis plays a key role in preventing the disease to the offspring.

Inclusion Criteria:

• No sperm was found after centrifugation for 15min for two or more semen tests, and the interval between two tests was at least 2 weeks.
• Blood FSH is normal;
• Hematostatin b is normal;
• Chromosome karyotype is normal or polymorphic;
• Y chromosome microdeletion did not show the deletion:(main locus);
• Biochemical fructose of seminal plasma : less than the normal value;
• PH of semen <7.2;
• Transscrotal or transrectal ultrasound: normal testicular size(as measured by B ultrasound), presence or dysplasia of vas deferens and epididymis;

Exclusion Criteria:

• B ultrasound of urinary system suggested abnormal development;
• Transscrotal or Transrectal ultrasound indicated absence of vas deferens or epididymis or seminal vesicle;
• Physical examination showed the following abnormalities: cryptorchidism, tenderness of testis and epididymis;
• The following medical history: genitourinary tract trauma or surgical history; orchitis; epididymitis; Seminal vesicle disease; mumps;
• Laboratory examination: red and white blood cell elevation of semen routine

This is a non-interventional multicenter study. The cases were mainly male outpatients from the Reproductive Center of our Hospital, Shenzhen Hospital of the University of Hong Kong and Shenzhen Hospital of Traditional Chinese Medicine. A total of 300 cases were planned to be enrolled. Through inclusion criteria and exclusion criteria, appropriate patients were selected for genetic testing, including sequence of known pathogenic genes (CFTR and ADGRG2) and whole- exome sequence. If patients were found to carry mutations in CFTR, ADGRG2 or other genes, verification of family members' blood samples was required to determine the pathogenicity of mutations.