16p13.11 Deletion Syndrome
16p13.11 deletion syndrome is also called 16p13.11 microdeletion syndrome. For this webpage, we will be using the name 16p13.11 deletion syndrome to encompass the wide range of variants observed in the people identified.
What is 16p13.11 deletion syndrome?
16p13.11 deletion syndrome happens when a person is missing a piece of chromosome 16, one of the body’s 46 chromosomes. Chromosomes are structures in our cells that house our genes. The missing piece can affect learning and how the body develops.
Key Role
Genes within the 16p13.11 region are important for brain development and function.
Symptoms
Because the 16p13.11 region is important in brain activity, many people who have 16p13.11 deletion syndrome have:
- Developmental delay
- Intellectual disability
- Poor or absent speech
- Seizures
- Motor coordination challenges
- Autism
What causes 16p13.11 deletion syndrome?
16p13.11 deletion 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 16p13.11 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 16p13.11 plays a key role in development, de novo variants in this gene can have a meaningful effect.
Research shows that 16p13.11 deletion syndrome is often the result of a de novo variant in 16p13.11. Many parents who have had their genes tested do not have the 16p13.11 genetic variant found in their child who has the syndrome. In some cases, 16p13.11 deletion syndrome happens because the genetic variant was passed down from a parent.
Autosomal dominant conditions
16p13.11 deletion syndrome is an autosomal dominant genetic condition. This means that when a person has the one damaging variant in 16p13.11 they will likely have symptoms of 16p13.11 deletion 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 or I have 16p13.11 deletion syndrome?
No parent causes their child’s 16p13.11 deletion syndrome. We know this because no parent has any control over the chromosome 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 genetic 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 16p13.11 deletion 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 16p13.11 deletion 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 16p13.11 deletion syndrome, the sibling’s risk of having a child who has 16p13.11 deletion syndrome depends on the sibling’s genes and their parents’ genes.
- If neither parent has the same genetic variant causing 16p11.2 deletion syndrome, the symptom-free sibling has a nearly 0 percent chance of having a child who would inherit 16p13.11 deletion syndrome.
- If one biological parent has the same genetic variant causing 16p11.2 deletion 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 16p13.11 deletion syndrome, the risk of having a child who has the syndrome is about 50 percent.
Do all people who have 16p13.11 deletion syndrome have symptoms?
Not necessarily. Some people do not have any symptoms. Some people may not learn that they have this genetic change until it is found in their children.
Will all of the people in a family that have 16p13.11 deletion syndrome have the same symptoms?
Not necessarily. Family members who have the same chromosome change can have different symptoms.
How many people have 16p13.11 deletion syndrome?
As of 2024, at least 82 people with 16p13.11 deletion syndrome have been identified in medical research. The first case was found in 2007.
Do people who have 16p13.11 deletion syndrome look different?
People who have 16p13.11 deletion syndrome may look different. Appearance can vary and can include some but not all of these features:
- Smaller than average head size
- Shorter than average nose
- Low-set ears
How is 16p13.11 deletion syndrome treated?
At this point, there are no medicines designed to treat 16p13.11 deletion 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:
- Physical exams and brain studies
- Genetics consults
- Developmental and behavior studies
- Other issues, as needed
A developmental pediatrician, neurologist, or psychologist can follow progress over time and can help:
- Suggest the right therapies. This can include physical, occupational, speech, or behavioral therapy.
- Guide individualized education plans (IEPs).
Specialists advise that therapies for 16p13.11 deletion 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: epilepsy.com/learn/types-seizures.
This section includes a summary of information from published articles. It highlights how many people have different symptoms. See the Sources and references section of this guide for a list of articles.
Behavior and development concerns linked to 16p13.11 deletion syndrome
The 16p13.11 deletion region differs from person to person and might have up to about 14 genes removed. Some people inherit the 16p13.11 deletion from a parent who may or may not have medical features.
Researchers think that an important gene within the 16p13.11 region is the NDE1 gene. The information below includes people with the 16p13.11 deletion and separately, people with a 16p13.3 deletion and a damaging variant in their non-deleted NDE1 gene.
Speech and Learning
Some people with 16p13.11 deletion syndrome had developmental delay or intellectual disability, as well as language delays.
- 43 out of 82 people had a developmental delay or intellectual disability (52 percent)
- 15 out of 39 people had language delays (39 percent)
All people studied with both a 16p13.11 deletion and an NDE1 damaging variant had intellectual disability.
- 15 out of 15 people had developmental delay or intellectual disability (100 percent)
Behavior
Some people with 16p13.11 deletion syndrome had features of autism.
- 9 out of 27 people had features of autism (33 percent)
Brain
Researchers think that about 0.6 percent of people with epilepsy have a 16p13.11 deletion. Epilepsy was common in people with the 16p13.11 deletion. Some people had a head size that was smaller than average, also called microcephaly. Some people had abnormal brain changes seen on magnetic resonance imaging (MRI).
- 33 out of 54 people had seizures (61 percent)
- 9 out of 31 people had microcephaly (29 percent)
- 10 out of 23 people had abnormal MRI findings (44 percent)
Seizure types included simple partial seizures, complex partial seizures, and secondarily generalized tonic-clonic seizures.
Almost all people studied with both a 16p13.11 deletion and an NDE1 damaging variant had seizures, microcephaly, or abnormal findings on MRI. MRI findings included hypoplastic cerebellum, ventricular enlargement, and corpus callosum agenesis.
- 12 out of 15 people had seizures (80 percent)
- 15 out of 15 people had microcephaly (100 percent)
- 15 out of 15 people had abnormal MRI findings (100 percent)
Medical and physical concerns linked to 16p13.11 deletion syndrome
Growth
Some people with 16p13.11 deletion syndrome were shorter than average.
- 3 out of 11 people were short in height (27 percent)
Mobility
Almost one-half of people with 16p13.11 deletion syndrome had motor delays as children.
- 12 out of 29 people had motor delays (41 percent)
Where can I find support and resources?
Unique – 16p13.11 Deletion Guidebook
Simons Searchlight
Simons Searchlight is an online international research program, building an ever growing natural history database, biorepository, and resource network of over 175 rare genetic neurodevelopmental disorders. By joining their community and sharing your experiences, you contribute to a growing database used by scientists worldwide to advance the understanding of your genetic condition. Through online surveys and optional blood sample collection, they gather valuable information to improve lives and drive scientific progress. Families like yours are the key to making meaningful progress. To register for Simons Searchlight, go to the Simons Searchlight website at www.simonssearchlight.org and click “Join Us.”
- Learn more about Simons Searchlight: www.simonssearchlight.org/frequently-asked-questions
- Simons Searchlight webpage with more information on 16p13.11 deletion: www.simonssearchlight.org/research/what-we-study/16p13-11-deletion/
- Simons Searchlight Facebook page for 16p13.11 deletion: Simons Searchlight 16p13.11 Deletion Facebook community
Sources and References
The content in this guide comes from published studies on 16p13.11 deletion syndrome. Below you can find details about each study, as well as links to summaries or, in some cases, the full article.
- Hannes, F. D., Sharp, A. J., Mefford, H. C., de Ravel, T., Ruivenkamp, C. A., Breuning, M. H., Fryns, J. P., Devriendt, K., Van Buggenhout, G., … Vermeesch, J. R. (2009). Recurrent reciprocal deletions and duplications of 16p13.11: The deletion is a risk factor for MR/MCA while the duplication may be a rare benign variant. Journal of Medical Genetics, 46(4), 223-232. https://pubmed.ncbi.nlm.nih.gov/18550696/
- Heinzen, E. L., Radtke, R. A., Urban, T. J., Cavalleri, G. L., Depondt, C., Need, A. C., Walley, N. M., Nicoletti, P., Ge, D., Catarino, C. B., … Goldstein, D. B. (2010). Rare deletions at 16p13.11 predispose to a diverse spectrum of sporadic epilepsy syndromes. American Journal of Human Genetics, 86(5), 707-718. https://pubmed.ncbi.nlm.nih.gov/20398883/
- Tan, L., Bi, B., Zhao, P., Cai, X., Wan, C., Shao, J., & He, X. (2017). Severe congenital microcephaly with 16p13.11 microdeletion combined with NDE1 mutation, a case report and literature review. BMC Medical Genetics, 18(1), 141. https://pubmed.ncbi.nlm.nih.gov/29191162/
- Tropeano, M., Ahn, J. W., Dobson, R. J., Breen, G., Rucker, J., Dixit, A., Pal, D. K., McGuffin, P., Farmer, A., … Collier, D. A. (2013). Male-biased autosomal effect of 16p13.11 copy number variation in neurodevelopmental disorders. PLoS One, 8(4), e61365. https://pubmed.ncbi.nlm.nih.gov/23637818/
- Redaelli, S., Maitz, S., Crosti, F., Sala, E., Villa, N., Spaccini, L., Selicorni, A., Rigoldi, M., Conconi, D., … Bentivegna, A. (2019). Refining the phenotype of recurrent rearrangements of chromosome 16. International Journal of Molecular Sciences, 20(5), 1095. https://pubmed.ncbi.nlm.nih.gov/30836598/