What is Dyskeratosis Congenita?
Dyskeratosis congenita (DC) is a rare, genetic form of bone marrow failure. It can affect different organs, including the skin, finger nails and lungs. It is estimated that one out of one million people has this condition.
Dyskeratosis Congenita Causes
Dyskeratosis congenita can be caused by changes (mutations) in the genes. About 50% of the people who have dyskeratosis congenita have changes in the DKC1, TERT, TERC or TINF2 genes. In rare instances, other genes can cause the condition.
These genes provide the body with instructions on how to make telomeres. Telomeres are structures on the ends of chromosomes that prevent the chromosomes from fraying or breaking down.
Changes in these genes cause the telomeres to get shorter and shorter. As the telomeres shrink, they cannot protect the chromosomes. The chromosomes can break or become unstable. This has the biggest impact on cells that divide often and quickly.
In some cases, people with dyskeratosis congenita do not have a known genetic change.
The DKC1 gene is an X-linked recessive change. The definition of "X-linked recessive" is a gene located on the X chromosome. The X chromosome is one of two sex chromosomes.
Because males have one X chromosome and one Y chromosome, a genetic change in their X chromosome is enough for them to have dyskeratosis congenita. Females have two X chromosomes, so changes would need to happen in both X chromosomes to have dyskeratosis congenita. This is very rare, which means most females with the change are just carriers. Males are much more likely to have the X-linked recessive change for dyskeratosis congenita.
Some people have autosomal recessive genetic change.
- "Autosomal" refers to a change that happens in the non-sex chromosomes.
- "Recessive" means that a child inherits two copies of the mutated gene with one coming from each parent.
A child who has an autosomal recessive change suggests that the parents are both carriers of the change. There is a 25% chance that their child will have the condition if both parents are carriers.
It is also possible to have dyskeratosis congenita from autosomal dominant genetic changes. "Dominant" indicates that a child only needs one copy of the changed gene to have the condition. The copy can come from either parent in this type of inheritance pattern.
A child who inherits an autosomal dominant change would only need one of the parents to have the genetic change. When only one parent has the change, there is a 50% chance that their child will have dyskeratosis congenita.
Dyskeratosis Congenita Symptoms
Dyskeratosis congenita is present at birth, but symptoms may not show up until a child is older. Sometimes symptoms may not appear until the teen or adult years.
People with dyskeratosis congenita often experience these three characteristics:
- Skin pigmentation problems and rashes that look like lacy patterns (especially on the neck or chest)
- Nails that grow slowly, are discolored or have unusual shapes
- Oral leukoplakia (white patches inside the mouth)
Dyskeratosis congenita can cause other problems as well, such as:
- Frequent infections
- Low energy and fatigue
- Bleeding problems
- Eye and dental problems
- Short stature
- Osteoporosis (low bone density)
- Developmental delays
- Aplastic anemia (when the body does not produce enough red blood cells)
- Myelodysplastic syndrome (when blood cells do not form properly or work correctly)
- Blood cancers such as leukemia and other types of cancers
- Fibrosis (scarring) in the lungs or liver
Dyskeratosis Congenita Diagnosis
Diagnosis of dyskeratosis congenita starts with a physical exam and symptom check. Your child also may have bone marrow testing and a blood test that includes a complete blood count.
Genetic testing can show changes in a child’s genes. Parents also may want to get tested to see if they are carriers of the genes that cause dyskeratosis congenita.
Dyskeratosis Congenita Treatment
Treatment for dyskeratosis congenita focuses on managing symptoms and diagnosing potential problems early, when treatment may be more effective.
Treatment may include:
- Bone marrow transplants (transplant of blood-forming stem cells)
- Androgen therapy (artificial hormones to increase red blood cells)
- Hematopoietic growth hormones such as granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) to increase white blood cells
- Hematopoietic stem cell transplant for aplastic anemia, myelodysplastic syndrome or leukemia
Dyskeratosis Congenita Long-Term Outlook
Dyskeratosis congenita affects every patient differently. Some people with DC have normal bone marrow function and a few mild physical features of the condition. Others are more severely affected and experience bone marrow failure, cancer or pulmonary fibrosis by early adulthood. In general, the effects of dyskeratosis congenita tend to get worse as a person gets older.
Although there is no cure, children who receive early treatment for dyskeratosis congenita may have a higher quality of life. Early diagnosis of problems such as cancer can lead to faster treatments and better outcomes.
