01
IN SHORT
Congenital Dyserythropoietic Anemias
CDA is a rare disease that prevents the body from making its red blood cells properly.
Our bone marrow constantly produces blood cells. In people with CDA, red blood cells are made abnormally, and some of them are destroyed before they can even do their job.
Many red blood cells are misshapen and don't work properly, so the body runs short of hemoglobin.
THIS IS CALLED
anemia
Normal blood
With CDA
02
WHAT HAPPENS IN THE BODY
What do our red blood cells do?
Bone marrow
It's the body's blood “factory”. In CDA, red blood cell production there is disrupted.
→
O₂
Red blood cells
Their job is to carry oxygen around the body. When there are too few of them, the organs get less oxygen.
→
Fatigue and other signs
Tiredness, pale skin, shortness of breath… Symptoms depend on how severe the anemia is.
In some people with CDA, the anemia is severe and requires regular blood transfusions.
03
A GENETIC DISEASE
How can healthy parents have a child with the disease?
CDA is caused by a change in one or more of the genes involved in making red blood cells.
Some forms are passed on in an autosomal recessive pattern: each parent can carry one copy of the altered gene while being perfectly healthy. A child only develops the disease if they inherit the altered copy from both parents.
Mom
carrier, healthy
+
Dad
carrier, healthy
With each pregnancy, there are 4 possibilities:
1 in 4
Healthy
non-carrier
1 in 4
Healthy
but a carrier
1 in 4
Healthy
but a carrier
1 in 4
Affected
by CDA
gene that works normally
altered gene (responsible for CDA)
Applies to forms of CDA with autosomal recessive inheritance.
04
PRESENT FROM BIRTH
… but not always visible right away
First days of life
for some forms
During childhood
most often
Sometimes later
depending on severity
“Congenital” means the disease is present from birth. That doesn't necessarily mean it is diagnosed straight away.
Depending on the type of CDA and its severity, the first signs may appear in the first days of life, during childhood or sometimes later. Common signs include:
anemia
jaundice
severe fatigue
05
LIVING WITH CDA
Transfusions and iron monitoring
Blood transfusions
Why do some people need them?
When the bone marrow can't produce enough healthy red blood cells, hemoglobin levels can drop too low.
Transfusions then temporarily provide the red blood cells the body needs to carry oxygen. How often they are needed varies from person to person and depends on the type of CDA.
What about iron?
Iron levels to keep an eye on
Repeated transfusions also bring iron into the body. Over time, it can build up in certain organs: this is called iron overload.
People who receive regular transfusions are therefore closely monitored, and sometimes treated to limit this build-up. Iron overload can also be caused by the disease itself, regardless of transfusions.
06
SEVERAL TYPES
There isn't just one CDA, but several
CDA is not a single disease: there are several types. They are caused by different genetic changes and can have different symptoms and courses.
I
CDA type I
II
CDA type II
Genetic testing is one of the main ways doctors can tell which type of CDA a person has.
III
CDA type III
07
A RARE DISEASE
Still little known — which is why research matters
CDA is a rare disease. Because rare diseases affect few people, they are often less studied and scientific knowledge remains limited.
For families, this often means many questions, few answers and highly specialized care.
That is why research is so important.
