CSNK2A1-Related Syndrome
CSNK2A1-related syndrome is also called Okur-Chung neurodevelopmental syndrome (OCNDS). For this webpage, we will be using the name CSNK2A1-related syndrome to encompass the wide range of variants observed in the people identified.
What is CSNK2A1-related syndrome?
CSNK2A1-related syndrome happens when there are changes to the CSNK2A1 gene. These changes can keep the gene from working as it should.
Key Role
The CSNK2A1 gene plays different roles in the body, including helping to control the birth of new cells and helping to control the day to night cycle of cells.
Symptoms
Because the CSNK2A1 gene is important in the development and function of brain cells, many people who have CSNK2A1-related syndrome have:
- Intellectual disability
- Feeding difficulties, gastric reflux, and constipation
- Global developmental delay
- Delayed speech, poor or absent speech
- Behavior issues and temper tantrums
- Attention deficit hyperactivity disorder, or ADHD
- Immunodeficiencies, in some people
What causes CSNK2A1-related syndrome?
CSNK2A1-related syndrome is a genetic condition, which means that it is caused by variants in genes. Our genes contain the instructions, or code, that tell our cells how to grow, develop, and work. Every child gets two copies of the CSNK2A1 gene: one copy from their mother’s egg, and one copy from their father’s sperm. In most cases, parents pass on exact copies of the gene to their child. But the process of creating the egg or sperm is not perfect. A change in the genetic code can lead to physical issues, developmental issues, or both.
Sometimes a spontaneous variant happens in the sperm, egg or after fertilization. When a brand new genetic variant happens in the genetic code is called a ‘de novo’ genetic variant. The child is usually the first in the family to have the genetic variant.
De novo variants can take place in any gene. We all have some de novo variants, most of which don’t affect our health. But because CSNK2A1 plays a key role in development, de novo variants in this gene can have a meaningful effect.
Research shows that CSNK2A1-related syndrome is often the result of a de novo variant in CSNK2A1. Many parents who have had their genes tested do not have the CSNK2A1 genetic variant found in their child who has the syndrome. In some cases, CSNK2A1-related syndrome happens because the genetic variant was passed down from a parent.
Autosomal dominant conditions
CSNK2A1-related syndrome is an autosomal dominant genetic condition. This means that when a person has the one damaging variant in CSNK2A1 they will likely have symptoms of CSNK2A1-related syndrome. For someone with an autosomal dominant genetic syndrome, every time they have a child there is a 50 percent chance they pass on the same genetic variant and a 50 percent chance they do not pass on the same genetic variant.
Autosomal Dominant Genetic Syndrome
Why does my child have a change in the CSNK2A1 gene?
No parent causes their child’s CSNK2A1-related syndrome. We know this because no parent has any control over the gene changes that they do or do not pass on to their children. Please keep in mind that nothing a parent does before or during the pregnancy causes this to happen. The gene change takes place on its own and cannot be predicted or stopped.
What are the chances that other family members or future children will have CSNK2A1-related syndrome?
Each family is different. A geneticist or genetic counselor can give you advice on the chance that this will happen again in your family.
The risk of having another child who has CSNK2A1-related syndrome depends on the genes of both biological parents.
- If neither biological parent has the same genetic variant found in their child, the chance of having another child who has the syndrome is on average 1 percent. This 1 percent chance is higher than the chance of the general population. The increase in risk is due to the very unlikely chance that more of the mother’s egg cells or the father’s sperm cells carry the same genetic variant.
- If one biological parent has the same genetic variant found in their child, the chance of having another child who has the syndrome is 50 percent.
For a symptom-free brother or sister of someone who has CSNK2A1-related syndrome, the sibling’s risk of having a child who has CSNK2A1-related syndrome depends on the sibling’s genes and their parents’ genes.
- If neither parent has the same genetic variant causing CSNK2A1-related syndrome, the symptom-free sibling has a nearly 0 percent chance of having a child who would inherit CSNK2A1-related syndrome.
- If one biological parent has the same genetic variant causing CSNK2A1-related syndrome, the symptom-free sibling has a 50 percent chance of also having the same genetic variant. If the symptom-free sibling has the same genetic variant, their chance of having a child who has the genetic variant is 50 percent.
For a person who has CSNK2A1-related syndrome, the risk of having a child who has the syndrome is about 50 percent.
How many people have CSNK2A1-related syndrome?
As of 2024, at least 65 people with CSNK2A1-related syndrome have been identified in a medical clinic.
How many people have CSNK2A1-related syndrome?
As of 2024, at least 65 people with CSNK2A1-related syndrome have been identified in a medical clinic. More people have been diagnosed with the syndrome. The first case of CSNK2A1-related syndrome was described in 2016. Scientists expect to find more people who have the syndrome as access to genetic testing improves.
Do people who have CSNK2A1-related syndrome look different?
People who have CSNK2A1-related syndrome may look different. Appearance can vary and can include some but not all of these features:
- Lower than average muscle tone
- Short height
- Smaller than average head size, also called microcephaly
- Round face
- Arched eyebrows
- A fold of skin from the upper eyelid, also called epicanthic folds
- Low set ears and changes in the ear folds
- Wide nasal bridge
- Smaller than average jaw, also called micrognathia
How is CSNK2A1-related syndrome treated?
Scientists and doctors have only just begun to study CSNK2A1-related syndrome. At this point, there are no medicines designed to treat the syndrome. A genetic diagnosis can help people decide on the best way to track the condition and manage therapies. Doctors can refer people to specialists for:
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- Physical exams and brain studies.
- Genetics consults.
- Development and behavior studies.
- Other issues, as needed.
A developmental pediatrician, neurologist, or psychologist can follow progress over time and can help:
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- Suggest the right therapies. This can include physical, occupational, speech, or behavioral therapy.
- Guide individualized education plans (IEPs).
Specialists advise that therapies for CSNK2A1-related syndrome should begin as early as possible, ideally before a child begins school.
If seizures happen, consult a neurologist. There are many types of seizures, and not all types are easy to spot. To learn more, you can refer to resources such as the Epilepsy Foundation’s website: www.epilepsy.com/learn/types-seizures.
This section includes a summary of information from major published articles. It highlights how many people have different symptoms. To learn more about the articles, see the Sources and references section of this guide.
Behavior and development concerns linked to CSNK2A1-related syndrome
Learning
Most people who have CSNK2A1-related syndrome have intellectual disability.
- 35 out of 35 had intellectual disability (100 percent)
Speech
Speech delay is common in people who have the syndrome, and some are slower to begin walking.
Sleep
Over one out of three people have sleep issues.
- 13 out of 36 had sleep issues (36 percent)
Behavior
About one out of four people have autism or features of autism. And about one in five people have attention deficit hyperactivity disorder, also called ADHD.
Medical and physical concerns linked to CSNK2A1-related syndrome
Muscle tone
Low muscle tone is common. Issues with the muscular-skeletal system happens in about one-half of people. This includes loose joints or sideways curvature of the spine, also called scoliosis.
- 22 out of 36 had low muscle tone (61 percent)
- 15 out of 36 have issues with muscles or the skeletal system (42 percent)
- 3 out of 26 people have a curved spine, also called scoliosis (12 percent)
Sitting and walking
The average age of being able to sit is 11 months, walking is about 29 months, and first meaningful words is 38 months (or about 3 years old).
Brain
Some people are diagnosed with a smaller-than-average head size, or seizures.
- 13 out of 34 have a smaller-than-average head size (38 percent)
- 9 out of 34 people have seizures (26 percent)
Feeding and Digestion Issues
Some people report issues with feeding and digestion. This can include acid reflux, constipation, difficulties swallowing, and difficulties controlling the lips, tongue, and jaw muscle, also called oromotor delay.
Birth defects
About one out of four people are born with heart issues. This can include a hole in the heart, also known as an atrial septal defect.
About one-half of children with a CSNK2A1-related syndrome have defects in their first teeth, such as longer than average front teeth, cracked teeth, missing enamel, small teeth, or fused teeth.
Where can I find support and resources?
CSNK2A1 Foundation
Email: info@csnk2a1foundation.org
www.csnk2a1foundation.org
Simons Searchlight is another research program sponsored and run by the Simons Foundation Autism Research Initiative, also known as SFARI. As part of the next step in your research journey, Simons Searchlight offers you the opportunity to partner with scientists and other families who have the same gene change. Simons Searchlight is a registry for more than 200 genetic changes that are associated with neurodevelopmental conditions, including autism spectrum disorder. Simons Searchlight makes it easier for researchers to access the information they need to advance research on a condition. To register for Simons Searchlight, click “Join Us” at the top of this page.
Other resources:
Sources and references
The content in this guide comes from published studies about CSNK2A1-related syndrome. Below you can find details about each study, as well as links to summaries.
- Okur V. et al. Human Genetics, 135, 699-705, (2016). De novo mutations in CSNK2A1 are associated with neurodevelopmental abnormalities and dysmorphic features www.ncbi.nlm.nih.gov/pubmed/?term=27048600
- Chiu ATG. et al. Clinical Genetics, 93, 880-890, (2018). Okur-Chung neurodevelopmental syndrome: Eight additional cases with implications on phenotype and genotype expansion www.ncbi.nlm.nih.gov/pubmed/29240241O
- wen CI. et al. American Journal of Medical Genetics Part A, 176, 1108-1114, (2018). Extending the phenotype associated with the CSNK2A1-related Okur-Chung syndrome-A clinical study of 11 individuals www.ncbi.nlm.nih.gov/pubmed/29383814
- Ming, et al. (2023). Caregiver‐reported dental manifestations in individuals with genetic neurodevelopmental disorders. International Journal of Paediatric Dentistry. https://pubmed.ncbi.nlm.nih.gov/37655712/
- Chung W, Okur V. Okur-Chung Neurodevelopmental Syndrome. 2022 Jun 9. In: Adam MP, Feldman J, Mirzaa GM, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2023. Available from: https://www.ncbi.nlm.nih.gov/books/NBK581083/