Congenital bilateral absence of vas deferens is genetically related to
**Core Concept**
Congenital bilateral absence of vas deferens (CBAVD) is a condition where both vas deferens are absent, leading to infertility in males. This condition is closely linked to cystic fibrosis (CF), a genetic disorder that affects the respiratory, digestive, and reproductive systems.
**Why the Correct Answer is Right**
CBAVD is associated with mutations in the CFTR gene, which codes for the cystic fibrosis transmembrane conductance regulator protein. This protein is responsible for regulating the transport of chloride ions across epithelial cell membranes. Mutations in the CFTR gene disrupt this function, leading to the production of thick, sticky mucus that can clog the reproductive tract and cause CBAVD. The absence of vas deferens in CBAVD is thought to be due to the failure of the vas deferens to develop properly during embryogenesis.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because CBAVD is not primarily associated with mutations in the FSHR gene, which codes for the follicle-stimulating hormone receptor.
**Option B:** This option is incorrect because CBAVD is not primarily associated with mutations in the GnRH gene, which codes for the gonadotropin-releasing hormone.
**Option C:** This option is incorrect because CBAVD is not primarily associated with mutations in the P53 gene, which is a tumor suppressor gene involved in cancer.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that CBAVD is a common cause of infertility in men, and a diagnosis of CBAVD should prompt further investigation for cystic fibrosis or other genetic disorders.
**Correct Answer:** C. Cystic fibrosis (CF)