CSNK2B

CSNK2B Neurodevelopmental Syndrome Research Summary (17 articles Spring 2024)

Collection and review of research in collaboration with Rebecca W. Dolan, Ph.D.* and the Simons Searchlight team.

The following is a summary of research on CSNK2B Neurodevelopmental Syndrome. Articles included in this summary are listed at the bottom of this page, in order from oldest to newest. 

To help understand the findings in CSNK2B research, some background information is included here. The CSNK2B gene contains instructions for cells of the body to make the CSNK2B protein subunit. This subunit combines with other subunits to make an important enzyme called casein kinase 2.

Background on Casein Kinase 2 (CSNK2 or CK2)

• CSNK2 is made of 4 protein subunits that are active in the brain and many other parts of the body:

• The instructions to make the CSNK2A1, CSNK2A2, and CSNK2B protein subunits are in genes located on three different chromosomes
• Genetic variants of the CSNK2A1 gene are associated with a condition known as Okur-Chung neurodevelopmental syndrome, which is also studied by Simons Searchlight

Clinical Information

As of 2024, 77 people with genetic changes in the CSNK2B gene have been described in medical research.

• 2 boys in France (Poirier 2017)
• 4 people in Japan (Sakaguchi 2017, Nakashima 2019, Ohashi 2021)
• 20 people in China (Li 2019, Yang 2021, Yang 2022)
• 1 person in the US (Selvam 2021)
• 25 people in an international consortium (Ernst 2021)
• 10 people in Italy (Bonanni 2021, Orsini 2022)
• 2 people in Brazil (Wilke 2022)
• 8 people in China (Zhang et al., 2022)
• 2 people in China (Chen et al., 2023)
• 2 people in Italy (Di Stazio et al., 2023)
• 1 person in China (Li et al., 2024)

Some of these articles include photos with permission of the parent or guardian. Most of these articles describe the person’s developmental history and symptoms, and some have magnetic resonance imaging (MRI) images and electroencephalogram (EEG) information. Having more published information on people with CSNK2B allows the medical community to make some general statements about disease presentation.

Common symptoms of people with CSNK2B Neurodevelopmental Syndrome genetic changes:

• Most people have intellectual disabilities or learning disabilities, language development disorders, and seizures before the age of 2
• Seizures, including myoclonic epilepsy, early-onset intractable epilepsy, tonic-clonic, and clustered seizures with normal EEG and MRI studies
• Some people are unable to control their seizures with medications, and others are able to control their seizures with levetiracetam (Keppra) or multiple epileptic medications
• Many people are shorter than average and have lower muscle tone
• Early onset seizures, clustered seizures, and delayed development are early clinical signs of CSNK2B Neurodevelopmental Syndrome

Genetic Variants

To date, all people reported in the literature with changes in CSNK2B have a genetic variant that is new in the child and not inherited from their parents. This type of change is also called “de novo.”

Locations of reported variants along the CSNK2B gene. Figure 2, from Yang 2022

In the general population, people have two working copies of the CSNK2B gene. CSNK2B Neurodevelopmental Syndrome is caused by having only one working copy of the CSNK2B gene. Researchers have looked to see if there is a connection between the specific location of variants within the CSNK2B gene and patient symptoms (Orsini 2022 and Yang 2022). So far, researchers have not been able to identify any links. However, people who specifically have the CSNK2B variants, p.Asp32His and p.Asp32Asn, have a different genetic conditioncalled craniodigital syndrome or intellectual disability-craniodigital syndrome (IDCS) by some researchers (Wilke 2022 and Asif 2022).

Other CSNK2B Research Findings

• In the first article ever published on CSNK2B, researchers took skin samples from a person with a disease-causing CSNK2B genetic variant and found that the cells did not have enough functional CSNK2B   protein subunit, resulting in less CSNK2 enzyme (Poirier 2017).
• Researchers studied CSNK2B genetic variants to see how they affect the CSNK2B   protein subunit (Nakashima 2019). They found that certain variants resulted in CSNK2B   protein subunits that were unusable and broken down by the cell. The researchers suggested that these genetic variants were disease-causing because there was not enough CSNK2 enzyme in cells due to the variants in CSNK2B (see background on CSNK2 above).
• Researchers reviewed variants in the CSNK2B gene and suggested that genetic changes to this gene can result in two different conditions (Wilke 2022). These findings suggest that CSNK2B Neurodevelopmental Syndrome, as originally described in Poirier 2017, is caused by a loss of function of the variant CSNK2B gene. Decreased amounts of the CSNK2B protein subunit do not allow for enough CSNK2 enzyme to be made (see background on CSNK2 above). This article reports on a second condition caused by a specific genetic change in the CSNK2B gene. Craniodigital syndrome is caused by the CSNK2B variant p.Asp32Tyr. More studies are needed to better understand how genetic variants affect protein function.
• To date, there has been only one comprehensive summary of people with known CSNK2B variants (Yang 2022). The summary table in this article includes height; development; seizure onset, type, and treatment; EEG information; and MRI findings. The researchers used the following categories for CSNK2B variants: 1) loss of function, and 2) missense variants. A missense variant is a specific spelling change that causes an amino acid substitution in the protein subunit which can change the way it functions They did not find differences in traits between those with loss of function variants and those with missense variants. They did not have any missense variants associated with craniodigital syndrome in this article.
• Similar to other articles summarized above, researchers found that CSNK2B Neurodevelopmental Syndrome happens when a genetic variant leads to a loss of CSNK2B protein (Asif 2022). Intellectual disability-craniodigital syndrome (IDCS) happens when there are very specific missense changes in the CSNK2B gene (p.Asp32His and p.Asp32Asn in this article). This article focuses on IDCS and how it affects the human body.

*Dolan is a mom of a child who had CSNK2B Neurodevelopmental Syndrome, which is caused by genetic variants in the CSNK2B gene. She is a retired botanist and plant ecologist at Butler University and has written annotated bibliographies on those topics. She taught genetics in introductory biology classes at Butler University occasionally, beginning in 1987, and she strives to understand current genetic conditions. She hopes for answers for all in the community as more research is done.

Articles are listed in order of oldest to newest

1. Poirier K. et al. Hum. Mutat. 38, 932-941 (2017) PubMed
2. Sakaguchi Y. et al. Hum. Mutat. 38, 1611-1612 (2017) PubMed
3. Nakashima M. et al. J. Hum. Genet. 64, 313-322 (2019) PubMed
4. Li J. et al. Sci. Rep. 9, 17909 (2019) PubMed
5. Selvam P. et al. Am. J. Med. Genet. A. 185, 539-543 (2021) PubMed
6. Ohashi I. et al. Clin. Dysmorphol. 30, 139-141 (2021) PubMed
7. Yang S. et al. Neurogenetics 22, 323-332 (2021) PubMed
8. Ernst ME. et al. Epilepsia. 62, e103-e109 (2021) PubMed
9. Bonanni P. et al. Seizure. 93, 133-139 (2021) PubMed
10. Wilke M. et al. J. Med. Case Rep. 16, 4 (2022) PubMed
11. Orsini A. et al. Genes (Basel). 13, 276 (2022) PubMed
12. Yang Q. et al. Front. Neurol. 13, 811092 (2022) PubMed
13. Asif M. et al. HGG. Adv. 3, 100111 (2022) PubMed
14. Zhang, W. et al. Front. in Neurosci. 16, 892768 (2022) PubMed
15. Chen, X. et al. Front. in Ped. 11, 967701 (2023) PubMed
16. Di Stazio, et al. Genes 14, 250 (2023) PubMed
17. Li, D., et al. Mol. Genet. Genomic. Med. 12, e2327 (2024) PubMed