Leukemia is a type of blood cancer that starts in the bone marrow, with certain types associated with different age groups.

Congenital leukemia is seen in young infants who are born with this cancer. Symptoms appear within the first few weeks of life.

Learn more about this rare type of cancer, including the possible causes, symptoms, and treatment options to discuss with a pediatrician.

Leukemia describes a group of blood cancers. It’s further classified into different subtypes based on the types of blood cells affected (myeloid or lymphoid cells) and how quickly it grows (acute or chronic).

While it’s possible to develop leukemia at any age, it’s most common in adults. However, according to the National Cancer Institute, if children do get cancer, leukemia is the most common type.

Congenital leukemia (CL) means that this type of cancer is present at birth, and clinical signs develop within the first 4 weeks of life.

CL is a rare occurrence and is different from childhood leukemia that develops later in a child’s life. In fact, it’s estimated that CL occurs in only 1 out of every 1 million to 5 million live births. It’s also thought that CL accounts for 0.8% of childhood leukemias overall.

In infants, the most common symptoms of CL are unusual skin lesions that might prompt a doctor to conduct testing.

One 15-year study found that over 90% of infants with CL had related skin symptoms. Depending on skin tone, this may look like a “blueberry muffin rash” with blotches of purple, blue, brown, or red.

Children with leukemia may have signs and symptoms such as:

In some cases, CL may result in stillbirth.

CL develops in utero before birth. Also, while some childhood leukemias develop alongside Down syndrome, this isn’t common with CL.

The exact cause of CL isn’t known. However, fetal exposure to toxins or some medications may be contributing factors. Researchers also note a possible genetic component, with up to 40% of infants born with leukemia presenting mutations in the KMTA2A gene.

Also, according to an older 2016 review, most cases of CL affect myeloid cells, one of two main types of cells involved in leukemia. This is different from childhood leukemias more generally, which primarily originate in lymphoid cells, another type of cell involved in leukemia.

For children with signs or symptoms of leukemia, the following tests may be performed:

  • physical exam
  • blood tests
  • imaging tests, such as CT and MRI scans
  • lumbar puncture, or spinal tap
  • bone marrow aspiration
  • biopsy

If a child needs a bone marrow aspiration or a biopsy, they may be sedated or given medication so that they sleep during the procedure and don’t feel the discomfort.

Chemotherapy is the primary form of treatment for CL.

Research suggests that chemotherapy may be especially helpful in the presence of KMTA2A gene mutations. However, beyond this treatment option, much more research is needed to determine potential future therapies for CL.

Additionally, a pediatric oncologist may recommend supportive care techniques to help improve quality of life and decrease the risk of complications. These include:

  • maintaining hydration and fluid balance
  • monitoring liver function
  • taking frequent blood counts

While the exact causes of CL aren’t known, it’s thought that drug or toxin exposures during pregnancy may be risk factors. KMTA2A gene mutations are other risk factors for this rare type of leukemia.

According to one clinical review, there are no identifiable risk factors associated with race, ethnicity, or gender when considering CL.

CL is considered to have a poor outlook, with one retrospective study and analysis estimating a 23% 2-year survival rate. The median lifespan was also determined to be 210 days.

Chemotherapy was found to slightly increase lifespan in such cases, particularly in infants with abnormal KMT2A genes. However, spontaneous remission is also possible with or without the use of chemotherapy.

Can leukemia be congenital?

The term “congenital” means that a particular condition is present at birth. While some babies may be born with leukemia, this is still considered a very rare event.

Is congenital leukemia hereditary?

Like other forms of leukemia, CL can’t be passed down from parent to child. However, certain genetic mutations may be inherited and can contribute to the formation of CL in a newborn. This is still considered rare.

What are the most common types of leukemia?

CL is a rare form of leukemia. The four main types of leukemia include:

  • acute lymphocytic leukemia (ALL)
  • acute myeloid leukemia (AML)
  • chronic lymphocytic leukemia (CLL)
  • chronic myelogenous leukemia (CML)

CL is a rare type of leukemia that develops in utero before a child is born. Symptoms may develop within the first month of life, with skin lesions being the most common.

To date, chemotherapy is the most reliable treatment option that may be particularly helpful in infants who might have CL due to inherited gene mutations.

Much more research is needed to determine the underlying causes and treatment options for this rare cancer.