Ron (male) and Hermione (female) are in a committed, stable, mutually respectful relationship and now are trying to have a baby. Though Ron and Hermione are able to have intercourse (sex) and the volume of semen produced by Ron seems appropriate, after trying for more than 1 year, they are still not able to successfully conceive a child. Both Ron and Hermione begin fertility testing.

For Ron & Hermione, using the information above, before any testing has been done, which of the following would potentially explain why Ron (male) might be infertile but there were no external symptoms?

His seminal vesicles are not able to make certain proteins and substrates

His hypothalamus is not able to produce any GnRH

His testes did not descend through the inguinal canal

His interstitial cells were incapable of producing testosterone

His hypothalamus is not able to produce any GnRH.

Explanation:

Gonadotrophin-releasing hormone (GnRH) is a hypothalamis hormone which when released by the hypothalamus is released into small blood vessels and transported to the pituitary gland. Here, it stimulates the production of two more hormones; follicle stimulating hormone and luteinising hormone. These hormones act on the testes to trigger and maintain reproductive functions. Follicle stimulating hormone and luteinising hormone are important in controlling the production of sperm in men as well as the production of testosterone.

When these hormones fail to be released, there is an absence of viable sperm cells that can fertilize an egg to make a baby in the semen. Semen could be produced however, it will consist majorly of prostatic fluid and fluid from other accessory organs such as the bulbourethral gland.

A lack of production of GnRH which occurs in childhood or adolescence prevents the boy child from attaining puberty. However, when this defect occurs in a grown man, it could be due to a number of reasons such as trauma.