An image of a man deep in thought, representing the challenges and genetic factors linked to male infertility.

Disclaimer: This article is for informational purposes only and is not intended to diagnose any conditions. LifeDNA does not provide diagnostic services for any conditions mentioned in this or any other article.

Male infertility is more common than many realize. In one third of the cases the cause of male infertility is unknown, but  in addition to physiological factors, both the lifestyle and genetics play a role.  Male infertility is a condition that affects many couples trying to conceive. It occurs when a man has difficulty conceiving a child due to problems with sperm production, or function.  While various factors contribute to infertility, genetics has an important role in sperm production and function.

Research suggests that rare genetic disorders are responsible for approximately 2% to 8% of male infertility cases. Understanding these and other genetic factors may help guide diagnosis, treatment, and reproductive options.

How Do Genetics Influence Male Fertility?

Our body functions like a well-coordinated system, with every part playing a specific role, including the reproductive system. Just as our gene variants determine traits like height, eye color, and hair type, they also control how a man’s reproductive system develops and functions. Genes regulate everything from hormone production to testicular growth and the complex process of making sperm, known as spermatogenesis. When these genetic instructions are correct, the body produces plenty of healthy sperm that can successfully fertilize an egg.

However, when there are genetic mutations or other abnormalities, this natural process may be disrupted, leading to infertility. Common genetic variations and rare genetic conditions may affect fertility in two main ways:

Disrupting Sperm Production – Some conditions interfere with spermatogenesis, leading to low sperm count, poor sperm quality, or even a complete lack of sperm.

Causing Structural Issues – Certain genetic mutations result in missing or malformed reproductive structures, preventing sperm from reaching the egg.

Conditions that may Impact Male Fertility 

Here are some common conditions that can  impact male fertility and may have a genetic basis :

Azoospermia

Azoospermia is a condition in which a man has no measurable sperm in his semen, making natural conception difficult. This can happen for two main reasons:

  1. Obstructive Azoospermia – A blockage in the reproductive tract prevents sperm from mixing with semen during ejaculation. This can be caused by infections, prior surgeries, or genetic conditions like cystic fibrosis.
  2. Non-Obstructive Azoospermia – The testes fail to produce sperm, often due to hormonal imbalances, genetic disorders, or testicular damage.

Because azoospermia can sometimes be linked to genetic abnormalities, genetic testing is an important part of the diagnosis. While this condition significantly reduces fertility, treatments like sperm retrieval procedures, in vitro fertilization (IVF), and intracytoplasmic sperm injection (ICSI) offer some men the chance to conceive biological children. Consulting a fertility specialist may help determine the best options for treatment.

Oligospermia

Oligospermia is a condition where a man has a lower-than-normal sperm count in his semen. In mild cases, natural conception may still be possible, but more severe cases can make pregnancy difficult without medical assistance. This condition can be caused by various factors, including genetic causes, infections, or hormonal imbalances. 

Malformed Sperm

Malformed sperm are sperm cells with abnormal shapes or structures that reduce their ability to fertilize an egg. Common abnormalities include multiple tails, misshapen heads, or poor movement, all of which make it harder for sperm to reach and penetrate the egg. When a man has a high percentage of malformed sperm, natural conception becomes difficult. In such cases, assisted reproductive techniques like intracytoplasmic sperm injection (ICSI) can help by selecting a healthy sperm and injecting it directly into the egg, increasing the chances of successful fertilization.

What Are the Major Genetic Causes of Male Infertility?

Several rare genetic conditions contribute to male infertility. The most common among those are listed below:

Y Chromosome Microdeletions

The Y chromosome carries essential genes for sperm production, and microdeletions in certain regions can remove important genetic material, leading to infertility. One key area affected is the Azoospermia Factor (AZF) region, where deletions can significantly reduce sperm count and quality. 

Since these deletions are passed from father to son, genetic counseling is recommended for affected men. While there is no cure, assisted reproductive technologies (ART) like intracytoplasmic sperm injection (ICSI) may help these men conceive biological children.

Klinefelter Syndrome 

Klinefelter syndrome is a condition where a boy is born with an extra X chromosome, so he has two X chromosomes and one Y chromosome instead of just one X and one Y. This happens in about 1 out of 1,000 boys and can make it hard for them to have children when they grow up. Boys with Klinefelter syndrome might have smaller testicles, not enough hair on their face or body, and sometimes they have trouble with things like talking or learning. While it’s hard for them to have kids in the usual way, doctors can sometimes help by taking sperm directly from the testicles and using special treatments to help them become fathers.

Cystic Fibrosis Gene Mutation & Congenital Absence of the Vas Deferens (CBAVD)

Cystic fibrosis (CF) is a serious condition that mainly affects the lungs and stomach, but it can also cause problems with having children. In men with CF, a gene called CFTR is changed, which can cause them to be born without the tubes that carry sperm (called the vas deferens). This means sperm can’t travel the normal way. 

Most men with CF have this problem, and some who carry the CF gene might have other issues that can lower their sperm count or stop sperm from being able to leave their body. Even though sperm can’t travel the normal way, special methods like sperm extraction with IVF and ICSI may help men with CF have children.

Chromosomal Translocations

A chromosomal translocation happens when the genetic material from one chromosome gets rearranged or moved to another chromosome. There are two main types:

  1. Reciprocal translocation – This is when parts of two chromosomes swap places.
  2. Robertsonian translocation – This occurs when two chromosomes fuse together, which reduces the total number of chromosomes in the cell.

Both types of translocations can sometimes lead to fertility problems, as they can affect the way sperm is made.

Studies on infertile men in Qatar revealed that chromosomal abnormalities were found in 9.59% of cases. The study reported that 10.8% of men with azoospermia and 7.5% of men with oligozoospermia had chromosomal abnormalities. Furthermore, men with chromosomal abnormalities had significantly lower sperm retrieval rates and lower ICSI success rates compared to men with idiopathic infertility. Genetic counseling can help assess reproductive risks, and ART may provide a solution for affected individuals.

Noonan Syndrome

Noonan syndrome is a rare genetic disorder caused by mutations in multiple genes, affecting physical and reproductive development. The condition is often diagnosed at birth and is associated with:

  • Distinctive facial features and skeletal abnormalities.
  • Congenital heart defects.
  • Intellectual disabilities.
  • Blood disorders.

Infertility in men with Noonan syndrome is linked to cryptorchidism (undescended testicles), which occurs in 60%-75% of affected males. If left untreated, undescended testicles may impair sperm development, leading to infertility. Some men with Noonan syndrome who did not experience cryptorchidism may still have reduced fertility.

How Is Genetic Male Infertility Diagnosed?

Genetic male infertility is diagnosed through a series of steps:

  • Semen Analysis: This test looks at the sperm count, movement (motility), and shape (morphology). Abnormalities in any of these can indicate fertility problems.
  • Physical Examination: A doctor checks for signs like small testicles, enlarged breast tissue (gynecomastia), or missing vas deferens, which can suggest a genetic issue.
  • Genetic Testing: If the semen analysis or physical exam shows potential problems, genetic tests are done. These tests check for mutations, chromosomal abnormalities, Y chromosome microdeletions which are linked to infertility.

Can Genetic Male Infertility Be Treated?

Genetic male infertility cannot be cured, but assisted reproductive technologies (ART) may provide alternatives for fatherhood. Here are some treatment options for male infertility:

  • Intracytoplasmic Sperm Injection (ICSI): This technique involves injecting a single sperm directly into an egg during in vitro fertilization (IVF). It’s typically used when sperm count is low, sperm movement is impaired, or other sperm-related issues are present.
  • Testicular Sperm Extraction (TESE): If sperm is not found in the ejaculate, sperm can be retrieved directly from the testicles. This procedure is often used when there is a blockage in the sperm ducts or when there’s no sperm production in the semen.
  • Sperm Donation: In cases where a man’s sperm is not viable or available, sperm from a donor can be used for fertilization. This option is used when biological reproduction is not possible due to severe infertility or other factors.

Are There Ways to Prevent Genetic Male Infertility?

While genetic infertility can’t be entirely prevented, early diagnosis, healthy lifestyle and interventions may improve reproductive options. Steps that may help include:

 

  • Maintain a Healthy Weight: Being either underweight or overweight can affect hormone levels and sperm production. A balanced diet and regular exercise can help maintain a healthy weight.
  • Manage Stress: Chronic stress can affect hormone levels and sperm production. Finding ways to manage stress, such as through relaxation techniques or exercise, can benefit fertility.
  • Regular Check-Ups: Early detection of any underlying health conditions, such as varicocele or infections, can help prevent fertility problems. Regular visits to a healthcare provider can help identify and address issues early.
  • Seek Early Treatment for Health Conditions: Conditions like diabetes, hypertension, or sexually transmitted infections (STIs) can impact fertility. Managing these health issues with medical guidance can help preserve fertility.

Genetic disorders are a common but often overlooked cause of male infertility. While the  conditions listed above can’t be cured, genetic testing, fertility treatments, and counseling may help men become fathers. 

References

  1. https://fertility.womenandinfants.org/services/male-infertility/genetic-disorders-infertility-in-men#
  2. https://fertility.womenandinfants.org/services/male-infertility/genetic-disorders-infertility-in-men#
  3. https://pmc.ncbi.nlm.nih.gov/articles/PMC5922002/