DICER1 syndrome

DICER1 syndrome is a rare hereditary condition. Because of a change in the DNA, children and adults with DICER1 syndrome have an increased risk of developing tumors. Most of these tumors are benign, but some can be cancerous. The syndrome can be diagnosed through DNA testing.

What causes DICER1 syndrome?

The (child’s) body consists of billions of cells. Each cell has a nucleus containing DNA – your genetic code. DNA is made up of thousands of genes, one of which is the DICER1 gene. In people with DICER1 syndrome, this gene does not function properly. How exactly this leads to tumor development is not yet fully understood.

DICER1 and cancer

People with DICER1 syndrome have an increased risk of developing certain tumors. All of these tumors are rare, and more than half of those with DICER1 syndrome are not expected to develop any tumor at all.
In children, the most common tumors are found in the lungs (pleuropulmonary blastoma and lung cysts) and the kidneys (cystic nephroma). Most children are diagnosed before the age of six. In teenagers and adults, the most common tumors occur in the ovaries (sex cord-stromal tumors) and the thyroid (goiter and thyroid cancer*).

When do we suspect DICER1 syndrome?

We consider DICER1 syndrome in a child when:

the syndrome occurs in the family;
the child develops a tumor that is typical for DICER1 syndrome;
a change is found in the tumor tissue that is known to cause DICER1 syndrome;
a change is found incidentally during genetic testing that causes DICER1 syndrome.

Monitoring and screening

By monitoring children with DICER1 syndrome regularly, we aim to detect tumors at an early stage. Children under the age of 8 are preferably monitored at the Princess Máxima Center. From the age of 8, monitoring is carried out by a (pediatric) endocrinologist at a university hospital.

The screening schedule distinguishes between essential monitoring (for everyone) and optional monitoring (to be considered based on individual circumstances).

Children with DICER1 syndrome are seen twice a year until the age of six, and once a year thereafter. We advise parents to contact their care team if their child develops symptoms between appointments.

Treatment recommendations for cancer

Children with DICER1 syndrome are treated according to the same treatment protocols as children without the syndrome.

Inheritance

Both men and women can inherit and pass on the DICER1 gene change. Each child of a parent with this genetic change has a 50% chance of inheriting it, whether they are a boy or a girl. This is called autosomal dominant inheritance.

Changes in the DICER1 gene can also occur in the egg cell, sperm cell, or shortly after fertilisation. In these cases, the condition is not inherited from either parent. The child with DICER1 syndrome is then the first person in the family to have it.

Testing options before or during pregnancy

Parents with DICER1 syndrome can undergo genetic testing either before or during pregnancy. This is called preimplantation genetic diagnosis (PGD) when done before pregnancy, and prenatal diagnosis (PND) when done during pregnancy.

If one of the parents carries the genetic change that causes DICER1 syndrome, an ultrasound scan can be performed during the last three months of pregnancy to examine the baby’s lungs. This allows doctors to detect an early stage of pleuropulmonary blastoma.