Will I Pass Glanzmann Thrombasthenia to My Baby?

If you have Glanzmann Thrombasthenia (GT), it is completely understandable to wonder if your future children will inherit the condition. For the vast majority of people with GT, the short answer is: it depends almost entirely on your partner’s genetics. Because the standard form of GT follows a specific genetic pattern, if your partner does not carry a GT gene mutation, none of your children will have the bleeding disorder. However, if your partner is a carrier, there is a 50% chance that each child will be born with GT.

How Glanzmann Thrombasthenia is Inherited

The most common form of Glanzmann Thrombasthenia is an autosomal recessive genetic disorder ^[1][2]. This means that for a person to have the condition, they must inherit two mutated copies of a specific gene (typically either the ITGA2B or ITGB3 gene)—one copy from each parent ^[3].

Because you have GT, you already have two mutated copies of the gene ^[1]. You will automatically pass one mutated copy to every child you have ^[2]. Whether or not your child develops GT depends entirely on the single gene copy they inherit from your partner.

Your Chances of Passing Down GT

Your risk of having a child with GT falls into one of two main scenarios:

Scenario 1: Your Partner is Not a Carrier

Because GT is an ultra-rare condition, it is highly unlikely that a random partner is a carrier unless they are a blood relative (such as a cousin) or come from a community where GT is more common ^[4]. If your partner does not have GT and does not carry a mutated GT gene, they will pass on a healthy, functioning gene to your children ^[2].

• The Result: 100% of your children will be carriers of GT ^[2].
• What this means for them: Carriers have one mutated gene and one normal gene ^[1]. They generally do not have bleeding symptoms and will live a normal life without the disease ^[5]. However, when they grow up and decide to have children, they will need to consider their own carrier status.

Scenario 2: Your Partner is a Carrier

A carrier is someone who has one normal gene and one mutated gene, but does not have the disease themselves ^[5]. If your partner happens to be a carrier, they have a 50% chance of passing their mutated gene to your child.

• The Result: With each pregnancy, there is a 50% chance your child will inherit two mutated genes (one from you, one from your partner) and have Glanzmann Thrombasthenia ^[1][2]. There is also a 50% chance they will inherit the healthy gene from your partner and only be a carrier ^[2].

Note: In exceptionally rare cases, GT can be inherited in an “autosomal dominant” pattern, meaning only one mutated gene from either parent is needed to cause the disease ^[6]. If you have this rare variant, your children would have a 50% chance of inheriting the disease regardless of your partner’s genetics. Your doctor can confirm which form you have.

Next Steps for Family Planning

Because the risk to your children depends heavily on your partner’s genetics, it is highly recommended to seek genetic counseling before starting a family ^[7]. A genetic counselor can help you navigate this process in several key ways:

• Partner Testing: Your partner can undergo carrier screening to determine if they have a mutated GT gene ^[8]. This is the most crucial step in understanding your specific risks.
• Exploring Your Options: If your partner is a carrier, a counselor can explain family planning options. This may include Preimplantation Genetic Testing (PGT), which is an IVF procedure that screens embryos for the GT mutation before pregnancy ^[9][10]. Prenatal testing during pregnancy is also an option ^[4].
• Pregnancy Management: Even if your child will not have GT, being pregnant when you have a bleeding disorder requires specialized care ^[9]. You will need a multidisciplinary medical team to manage the risks of severe bleeding during childbirth. They will also monitor you for the development of alloantibodies ^[11]. These are immune proteins that can sometimes develop after blood or platelet transfusions; they can cross the placenta to affect the baby’s platelets or make future transfusions more complicated for you ^[11].

Having a bleeding disorder does not prevent you from having a healthy family, but it does require careful planning, open conversations with your partner, and proactive guidance from a knowledgeable medical team.