The diagnosis of congenital athymia can be overwhelming. Here you will find answers to common questions families have at the time of diagnosis.

What is congenital athymia?

Congenital athymia is an ultra-rare condition in which a child is born without a thymus.

How is congenital athymia diagnosed?

Congenital athymia is usually first detected in newborn screening for Severe Combined Immunodeficiency (SCID), which is required in all 50 states. Congenital athymia is not SCID, but the test for SCID will show if there is a low number of T-cells, which is seen in congenital athymia. Based on the results of this newborn screening, your healthcare provider will determine what additional testing may be needed. After a positive newborn SCID screening result, a laboratory technique called flow cytometry is used to verify low naive T-cells and strengthens the diagnosis of congenital athymia.

What is a thymus and why is it important?

The thymus is an organ that sits on top of the heart and plays an important role in how the immune system works. The immune system is made of organs, cells and proteins that work together throughout the body to fight infections. The thymus helps the body produce T-cells, which are white blood cells that fight off viruses, bacteria, fungi, and parasites. These cells also help the body remember the invaders it fights, which is how the body builds immunity to illnesses.

What happens when the thymus is missing?

Children with congenital athymia can face repeated infections because they do not have enough working T-cells to fight the invaders off. Without working T-cells, children can also be affected by autoimmune conditions, which is when the body’s immune system attacks and destroys healthy body tissue by mistake. These infections and autoimmune conditions can be fatal.

What causes congenital athymia?

Congenital athymia usually occurs in babies who have certain genetic problems but for some there is no known cause. Here are conditions that have been associated with congenital athymia:

DiGeorge syndrome

This syndrome results when a part of chromosome 22 is missing.

CHARGE syndrome

This syndrome consists of medical and physical conditions that differ child to child. The CHARGE acronym comes from the first letter of some of the more common features seen in children:

  • CColoboma or defects in the way the eye looks
  • HHeart defects
  • AAtresia of the choanae or blocked nasal breathing passages
  • RRetardation of growth and development
  • GGenital underdevelopment
  • EEar abnormalities

FOXN1 deficiency

This condition affects the production of critical proteins which results in a severely compromised immune system and problems with the growth of hair and nails.

"Mitch was diagnosed with congenital athymia after birth, within about a week. We were fortunate to have an early diagnosis."

Lacee, Mitch’s mom

Mitch

Patient with congenital athymia

Congenital Athymia Care

Upon diagnosis of congenital athymia, isolation measures are important for your child to avoid contact with germs that can cause infection. Here are recommendations on what to do to minimize risk of infection.

How do I minimize the chance of infection?

Always talk to your healthcare provider to create a plan for what is right for you and your family. Here are some things that your healthcare provider may recommend:

  • Restrict visitors in the home
  • Encourage frequent handwashing in the home
  • Wipe down any items coming into the home
  • Remind family members that they should shower and change clothes upon re-entry to the home from work or school
  • Homeschool other children in the family and work from home, if possible – if siblings must attend school, ask the school to notify you of any outbreaks or illnesses that siblings might bring home
  • Work with healthcare provider to prevent exposure to sick children at medical appointments
How do I minimize infection risk outside our home?

Talk to your healthcare provider on recommended practices but here are a few to consider:

  • Should anyone in your household get sick, have a plan in place for that family member to stay outside of the home, such as with a friend/family member until they are well enough to come home
  • Talk to those around you, family, friends, teachers, about what congenital athymia is and what it means for your family

Supporting the Treatment Journey

Enzyvant CONNECT is here to provide education, resources and support throughout your child’s treatment journey.

Visit EnzyvantConnect.com
Indication and Important Safety Information
IMPORTANT SAFETY INFORMATION

Infection Control: Immune reconstitution sufficient to protect from infection is unlikely to develop prior to 6-12 months after treatment with RETHYMIC. Immune reconstitution is needed for the body to produce cells in the immune system to fight infection. Your child’s healthcare provider should advise you of infection control measures which should be followed immediately after treatment and until the immune system starts working at a sufficient level. Monitor your child closely for signs of infection, including fever. Your child should be maintained on immunoglobulin replacement and prophylactic antimicrobials until certain criteria are met as determined by your healthcare provider.

Graft versus Host Disease (GVHD): RETHYMIC may cause or make pre-existing GVHD worse. Your child will be monitored for GVHD and treated if needed. Symptoms of GVHD may include fever, rash, enlarged lymph nodes, inflammation of the gastrointestinal system and/or diarrhea.

Autoimmune Disorders: Autoimmune-related adverse events occurred in patients treated with RETHYMIC. These events included: low platelets, low white blood cells, protein in urine, low red blood cells, hair loss, poor thyroid function, inflammation of liver, inflammation of the joints, inflammation of the spinal cord, loss of pigment in the skin, eyes and hair, overactive thyroid function, and loss of function of the ovaries. Your healthcare provider will monitor your child regularly including performing blood tests.

Kidney Disease: Treatment with RETHYMIC is a risk factor for death in patients with pre-existing kidney disease. Cytomegalovirus (CMV) Infection: In clinical studies with RETHYMIC, 3 out of 4 patients with pre-existing CMV infection prior to the implantation with RETHYMIC died. Talk to your healthcare provider about the benefits/risks of treatment if your child has pre-existing CMV infection.

Cancer: Due to your child’s weakened immune system, there is increased risk of developing certain cancers. Your child’s healthcare provider will monitor your child through testing for Epstein-Barr virus (EBV) and cytomegalovirus (CMV), which are two viruses that can cause cancer.

Transmission of Serious Infections: Because RETHYMIC is made from human tissue, and animal products are used in the manufacturing process, transmission of infectious diseases may occur. Vaccinations: Your child should not receive any vaccinations until he or she has met certain requirements set by your healthcare provider. Talk to your child’s healthcare provider prior to any vaccinations.

Anti-HLA Antibodies: Prior to receiving RETHYMIC your child will be tested for HLA antibodies, which are proteins that may be present in your child’s blood. If your child has these antibodies, he/she will need to receive RETHYMIC from a donor that does not express those HLA proteins.

HLA Typing: If your child has received a hematopoietic cell transplantation (HCT) or a solid organ transplant, they will have a test to look for specific antibodies that could interfere with the effect of RETHYMIC. If they are present, then it will be necessary to receive RETHYMIC from a certain group of donors that do not have these proteins.

Deaths: 105 children participated in the clinical studies of RETHYMIC. 29 of the patients died, including 23 in the first year after implantation of RETHYMIC.

What are the most common side effects with RETHYMIC?

The most common side effects with RETHYMIC are hypertension (high blood pressure), cytokine release syndrome, rash, hypomagnesemia (low magnesium), renal impairment / failure (decrease of kidney function), thrombocytopenia (low platelets), and graft versus host disease.

These are not all of the possible side effects of RETHYMIC.

Talk to your child’s healthcare provider about any side effect that bothers your child or does not go away.

You are encouraged to report side effects to the FDA at 1-800-FDA-1088 or www.fda.gov/safety/medwatch.

INDICATION

RETHYMIC® (allogeneic processed thymus tissue–agdc) is indicated for immune reconstitution in pediatric patients with congenital athymia. RETHYMIC is not for use in patients who have been diagnosed with severe combined immunodeficiency (SCID).

Indication and Important Safety Information
IMPORTANT SAFETY INFORMATION

Infection Control: Immune reconstitution sufficient to protect from infection is unlikely to develop prior to 6-12 months after treatment with RETHYMIC. Immune reconstitution is needed for the body to produce cells in the immune system to fight infection. Your child’s healthcare provider should advise you of infection control measures which should be followed immediately after treatment and until the immune system starts working at a sufficient level. Monitor your child closely for signs of infection, including fever. Your child should be maintained on immunoglobulin replacement and prophylactic antimicrobials until certain criteria are met as determined by your healthcare provider.

Graft versus Host Disease (GVHD): RETHYMIC may cause or make pre-existing GVHD worse. Your child will be monitored for GVHD and treated if needed. Symptoms of GVHD may include fever, rash, enlarged lymph nodes, inflammation of the gastrointestinal system and/or diarrhea.

Autoimmune Disorders: Autoimmune-related adverse events occurred in patients treated with RETHYMIC. These events included: low platelets, low white blood cells, protein in urine, low red blood cells, hair loss, poor thyroid function, inflammation of liver, inflammation of the joints, inflammation of the spinal cord, loss of pigment in the skin, eyes and hair, overactive thyroid function, and loss of function of the ovaries. Your healthcare provider will monitor your child regularly including performing blood tests.

Kidney Disease: Treatment with RETHYMIC is a risk factor for death in patients with pre-existing kidney disease. Cytomegalovirus (CMV) Infection: In clinical studies with RETHYMIC, 3 out of 4 patients with pre-existing CMV infection prior to the implantation with RETHYMIC died. Talk to your healthcare provider about the benefits/risks of treatment if your child has pre-existing CMV infection.

Cancer: Due to your child’s weakened immune system, there is increased risk of developing certain cancers. Your child’s healthcare provider will monitor your child through testing for Epstein-Barr virus (EBV) and cytomegalovirus (CMV), which are two viruses that can cause cancer.

Transmission of Serious Infections: Because RETHYMIC is made from human tissue, and animal products are used in the manufacturing process, transmission of infectious diseases may occur. Vaccinations: Your child should not receive any vaccinations until he or she has met certain requirements set by your healthcare provider. Talk to your child’s healthcare provider prior to any vaccinations.

Anti-HLA Antibodies: Prior to receiving RETHYMIC your child will be tested for HLA antibodies, which are proteins that may be present in your child’s blood. If your child has these antibodies, he/she will need to receive RETHYMIC from a donor that does not express those HLA proteins.

HLA Typing: If your child has received a hematopoietic cell transplantation (HCT) or a solid organ transplant, they will have a test to look for specific antibodies that could interfere with the effect of RETHYMIC. If they are present, then it will be necessary to receive RETHYMIC from a certain group of donors that do not have these proteins.

Deaths: 105 children participated in the clinical studies of RETHYMIC. 29 of the patients died, including 23 in the first year after implantation of RETHYMIC.

What are the most common side effects with RETHYMIC?

The most common side effects with RETHYMIC are hypertension (high blood pressure), cytokine release syndrome, rash, hypomagnesemia (low magnesium), renal impairment / failure (decrease of kidney function), thrombocytopenia (low platelets), and graft versus host disease.

These are not all of the possible side effects of RETHYMIC.

Talk to your child’s healthcare provider about any side effect that bothers your child or does not go away.

You are encouraged to report side effects to the FDA at 1-800-FDA-1088 or www.fda.gov/safety/medwatch.

INDICATION

RETHYMIC® (allogeneic processed thymus tissue–agdc) is indicated for immune reconstitution in pediatric patients with congenital athymia. RETHYMIC is not for use in patients who have been diagnosed with severe combined immunodeficiency (SCID).