Genetic Diseases That Cause Infertility: How PGT Helps in Early Detection

Infertility is often explained in terms of hormonal imbalance, lifestyle factors, or structural problems in the reproductive system. However, for a significant number of couples, the underlying cause lies deeper within their genetic makeup.

Genetic Diseases That Cause Infertility are increasingly recognized as an important but under-discussed factor in reproductive health. Advances in reproductive genetics, particularly PGT (Preimplantation Genetic Testing), have transformed how these conditions are identified early and managed effectively.

This article provides an evidence-based, educational overview of how genetic disorders contribute to infertility and how PGT supports early detection, with context relevant to Nepal, where in-house PGT capability is now available.

Understanding Infertility Beyond Hormones and Anatomy

Infertility is medically defined as the inability to conceive after 12 months of regular, unprotected intercourse. Globally, infertility affects an estimated 10–15% of couples, and genetic factors are believed to contribute to up to 15–30% of unexplained infertility cases.

While hormonal and anatomical evaluations are often the first step, they do not always reveal the root cause especially when embryos repeatedly fail to implant or result in early pregnancy loss.

This is where genetic evaluation becomes critical.

 

What Are Genetic Diseases That Cause Infertility?

Genetic diseases that cause infertility are conditions where abnormalities in chromosomes or genes interfere with:

• Gamete (egg or sperm) development
• Fertilization
• Embryo development
• Implantation
• Early pregnancy maintenance

These genetic issues may be inherited, spontaneous, or age-related.

Importantly, many individuals carrying genetic abnormalities do not show outward symptoms, making diagnosis difficult without specialized testing.

 

Common Genetic Conditions Linked to Infertility

1. Chromosomal Aneuploidy

Aneuploidy refers to an abnormal number of chromosomes.

Examples include:

• Missing chromosomes
• Extra chromosomes

These abnormalities are a leading cause of:

• Failed implantation
• Recurrent IVF failure
• Early miscarriage

The risk of aneuploid embryos increases significantly with maternal age.

 

2. Balanced Chromosomal Translocations

Some individuals carry chromosomal rearrangements that do not affect their health but can disrupt embryo development.

Effects include:

• Recurrent pregnancy loss
• Infertility despite normal sperm and egg counts

These conditions are often detected only after repeated reproductive failure.

 

3. Single-Gene Disorders

Certain inherited disorders directly or indirectly affect fertility or embryo viability.

Examples include:

• Cystic fibrosis gene mutations (often linked to male infertility)
• Thalassemia carrier status
• Spinal muscular atrophy (carrier state)

When both partners carry the same mutation, the risk of affected embryos increases.

 

4. Y-Chromosome Microdeletions

In men, small deletions on the Y chromosome can impair sperm production.

This can result in:

• Low sperm count
• Poor sperm quality
• Complete absence of sperm (azoospermia)

Genetic testing is essential in such cases before assisted reproduction.

 

Why Genetic Causes Often Go Undetected

Traditional fertility testing focuses on:

• Hormone levels
• Ultrasound findings
• Semen analysis

While important, these tests do not evaluate genetic integrity of embryos.

As a result:

• Embryos may look normal but carry genetic abnormalities
• Implantation may fail repeatedly
• Pregnancies may end early without explanation

This gap in diagnosis has historically limited treatment success.

 

What Is PGT (Preimplantation Genetic Testing)?

PGT is an advanced laboratory technique used during IVF to analyze the genetic material of embryos before implantation.

It allows clinicians to:

• Identify embryos with normal chromosome numbers
• Detect specific genetic mutations
• Select embryos with the highest chance of healthy development

PGT does not modify embryos; it only evaluates them.

 

Types of PGT and Their Purpose

Type of PGT	Purpose
PGT-A	Detects chromosomal aneuploidy
PGT-M	Screens for specific inherited genetic diseases
PGT-SR	Identifies structural chromosomal rearrangements

Each type is used based on individual medical and family history.

 

How PGT Helps in Early Detection of Genetic Infertility

PGT plays a preventive role by identifying problems before pregnancy begins.

Key benefits include:

• Reduced risk of miscarriage
• Improved implantation rates
• Lower likelihood of genetic disease transmission
• More informed decision-making

For couples with unexplained infertility or recurrent pregnancy loss, PGT often provides long-awaited answers.

 

PGT and IVF: How the Process Works

The process typically involves:

1. IVF to create embryos
2. Embryo culture to the blastocyst stage
3. Biopsy of a few cells from each embryo
4. Genetic analysis in a specialized laboratory
5. Selection of genetically suitable embryos for transfer

This integrated approach improves the efficiency and safety of assisted reproduction.

 

Availability of PGT in Nepal

Until recently, genetic testing of embryos required sending samples abroad, increasing:

• Cost
• Turnaround time
• Risk of sample handling issues

Today, Slavica I.V.F. and Research Center Pvt. Ltd. offers the only in-house PGT facility in Nepal, marking a significant advancement in reproductive genetics within the country.

Having PGT in Nepal allows for:

• Faster results
• Greater laboratory control
• Improved coordination between IVF and genetics teams

This development represents an important step forward in fertility care standards.

 

Genetic Diseases That Cause Infertility: Who Should Consider PGT?

PGT may be considered in cases such as:

• Recurrent IVF failure
• Recurrent pregnancy loss
• Known genetic disorders in one or both partners
• Advanced maternal age
• Severe male factor infertility

Evaluation is individualized and guided by reproductive specialists and genetic counselors.

 

Evidence Supporting the Use of PGT

Clinical studies have shown that:

• Aneuploid embryos account for over 50% of failed implantations in women over 38
• PGT-A can reduce miscarriage rates in selected patient groups
• PGT-M effectively prevents transmission of known genetic disorders

While PGT is not required for all IVF cases, evidence supports its role in specific indications.

 

Ethical and Clinical Considerations

PGT is regulated by strict laboratory and ethical standards.

Important points include:

• Testing is limited to medical indications
• Embryo selection is based on health, not traits
• Counseling is essential before and after testing

Transparent communication ensures ethical and informed use of technology.

 

Role of Genetic Counseling

Genetic counseling helps couples:

• Understand test results
• Assess risks accurately
• Make informed reproductive decisions

Counseling is especially important when dealing with inherited genetic conditions.

 

Limitations of PGT

While powerful, PGT has limitations:

• It cannot detect all genetic conditions
• Mosaic embryos may require complex interpretation
• It does not guarantee pregnancy

PGT should be viewed as a risk-reduction tool, not a guarantee.

 

Impact on Infertility Outcomes

By addressing genetic causes directly, PGT can:

• Shorten time to successful pregnancy
• Reduce emotional and physical burden
• Improve overall IVF efficiency

For many couples, this translates into more predictable and informed treatment pathways.

 

Medical Review & Professional Disclaimer

This article is intended for educational and awareness purposes only. Decisions regarding IVF, PGT, and genetic testing should be made in consultation with qualified fertility specialists and genetic professionals.

 

Frequently Asked Questions (FAQ)

What are genetic diseases that cause infertility?

They are inherited or acquired genetic abnormalities that interfere with reproduction or embryo development.

What is PGT used for?

PGT screens embryos for chromosomal or genetic abnormalities before implantation.

Is PGT available in Nepal?

Yes. Slavica IVF offers the only in-house PGT facility in Nepal.

Does PGT guarantee pregnancy?

No, but it improves the likelihood of healthy implantation in selected cases.

Who benefits most from PGT?

Couples with recurrent pregnancy loss, IVF failure, or known genetic risks.

 

Final Perspective

Genetic Diseases That Cause Infertility represent a complex but increasingly manageable challenge in reproductive medicine. With the integration of PGT into IVF care and the availability of in-house genetic testing at Slavica IVF early detection and informed decision-making are now more accessible in Nepal.

Understanding genetics empowers couples and clinicians to move beyond trial-and-error and toward precision-based fertility care.