An image of siblings smiling while holding each other.

Can Cord Blood Be Used for Siblings?

In New Zealand, families are participating in a study that will use one of their son’s cord blood stem cells to research treatment for another son’s cystic fibrosis. In Chicago, people are using their sibling’s stem cells to successfully treat sickle cell disease. And countless other families have banked their second child’s cord blood after their first child was diagnosed with leukemia. Many of those children are alive and well today thanks to their sibling’s stem cells. Since the first successful cord blood stem cell transplant on a sibling in 1988, over 30,000 cord blood transplants have been performed worldwide.

By banking your newborn’s cord blood, you could be storing a treatment not just for them, but for their siblings.

Younger Brother’s Cord Blood Stem Cells Successfully Treats Older Brother’s Sickle Cell

In 2021, 10-year-old Eli Cola-Achille received an FDA-approved transfusion of his younger brother Gus’ cord blood and bone marrow stem cells under the care of doctors at the Dana-Farber Cancer Institute in Boston, Massachusetts. The transfusion has helped to reduce the frequency of painful crises caused by his disease. This type of therapy has been shown to drastically improve the quality of life for patients suffering from sickle cell disease.

The family’s doctors deemed the treatment an overall success, with Eli now able to live a much more comfortable and normal life. He is able to attend school and engage in activities that were once difficult due to the frequency of his crises. This story highlights the power and importance of cord blood banking, as it provides a valuable resource for treatments such as this one. For the full story, check it out here.

How Do Stem Cells Match by Siblings and Genetics?

We are genetically closest to our siblings. That’s because we inherit half of our DNA from our mother and half from our father, so the genes we inherit are based on a chance combination of our parents. Our siblings are the only other people inheriting the same DNA.

When a child develops a condition that can be treated with stem cells, they undergo a transplant. A doctor infuses stem cells from cord blood or bone marrow into the patient’s bloodstream, where they will turn into cells that fight the disease and repair damaged cells—essentially, they replace and rejuvenate the existing immune system.

Like most transplants, the stem cells must be a genetic match with the patients to be accepted by the body’s immune system. It goes without saying that a patient’s own cord blood will be a 100% match. The second highest chance of a genetic match comes from siblings.

If siblings are a genetic match, a cord blood transplant is a simple procedure that is FDA-approved to treat over 80 serious conditions. However, there are a few considerations you should make before deciding to only bank one of your children’s blood:

What Are the Advantages of Using Cord Blood Stem Cells From a Sibling?

  • Siblings’ cord blood offers a higher potential for a genetic match.
  • If you choose to bank privately, your child’s cord blood will be available on-demand.

What Are the Disadvantages of Cord Blood Stem Cells From a Sibling?

  • While the chances of a sibling being a genetic match are higher, the only 100% certain match will be the child’s own cord blood (autologous).
  • The children must be whole siblings for the match to have substantial potential; half-siblings likely will not be a match.
Siblings having a consultation with a doctor.

When Can Siblings Use Cord Blood?

Stem cells from cord blood can be used for the newborn, their siblings, and potentially other relatives. Patients with genetic disorders like cystic fibrosis, cannot use their own cord blood and will need stem cells from a sibling’s cord blood. In the case of leukemia or other blood disorders, a child can use either their own cord blood or their sibling’s for treatment.

Here’s a quick guide to which conditions can usually be treated with a sibling’s cord blood (allogenic), and which can be treated using a child’s own cord blood (autologous):


Leukemias - Allogeneic

Myelodysplastic syndromes - Allogeneic

Lymphoma - Allogeneic

Aplastic anemia- Both

Inherited immune system disorders - Allogeneic

Phagocyte disorders - Allogeneic

Bone marrow cancers - Both

Neuroblastoma - Autologous

Clinical trial stages

Autism - Autologous

Cerebral Palsy - Both

Hearing loss - Autologous

MS - Autologous

Lupus - Both

In the future, scientists believe that cord blood has the potential to treat Alzheimer’s, ALS, muscular dystrophy, diabetes, arthritis, and many more.

Can Cord Blood Be Used To Treat a Parent or Grandparent?

Generally not, but there is a chance. The reason siblings are more likely to match is that they get half of their HLA markers from each parent. Based on the way parents pass on genes, there is a 25 percent chance that two siblings will be a whole match, a 50 percent chance they will be a half match and a 25 percent chance that they will not be a match at all. It is very rare for a parent to be a match with their own child, and even more rare for a grandparent to be a match.

Call to action guiding readers to download the Americord info guide to prepare for their family's healthy future.

If I Banked Privately for One Child, Do I Need To Do It for Additional Children?

You certainly should, especially if you have a family history of any conditions that could be treated with cord blood stem cells. As there is no guarantee of a suitable match, we recommend banking the cord blood of each individual child. We understand that can be a costly proposition, which is one of the reasons we offer competitively priced and flexible payment options. You can also compare several cord blood banks now to find the perfect fit for your family. 

If a sibling of a child whose cord blood you banked needs a transplant, then your chances of a match will be far higher than turning to the public. However, the safest bet is to bank the cord blood of all your children, safeguarding them against a number of conditions and doing your best to ensure a genetic match if necessary.


The views, statements, and pricing expressed are deemed reliable as of the published date. Articles may not reflect current pricing, offerings, or recent innovations.