In male infertility evaluation for severe oligo-/azoospermia, which tests are commonly considered?

• A. Y-chromosome microdeletion testing and karyotype; CFTR testing if congenital bilateral absence of the vas deferens is suspected
• B. Only Y-chromosome microdeletion testing
• C. CFTR testing for all infertile men
• D. Karyotype alone

Answer: (A)

In evaluating severe oligo- or azoospermia, you’re looking for genetic causes that explain failing sperm production and that also affect counseling and management. Y-chromosome microdeletions, especially in the AZF regions, are a common genetic cause of spermatogenic failure and can influence the likelihood of retrieving sperm with procedures like TESE, as well as long-term reproductive planning. A karyotype is important to detect sex chromosome abnormalities (such as Klinefelter syndrome) or other structural changes that underlie infertility and carry implications for offspring risk.

CFTR mutations are specifically tested when there is suspicion of congenital bilateral absence of the vas deferens, since CBAVD is often linked to CFTR mutations and carries implications for genetic counseling and CF screening in offspring. This is not routinely needed in all infertile men, but is added if CBAVD is suspected.

So, the best approach typically includes Y-chromosome microdeletion testing and karyotype for all cases, with CFTR testing added if CBAVD is suspected.