22q11.2 duplication means that there is a very small extra piece of genetic material on the long arm of the 22nd chromosome. Most often this extra piece is a copy (or duplicate) of the piece next to it.
Chromosomes are found in most cells of our bodies and contain the genetic information or blueprints for our body to grow and function. These chromosomes come in 23 pairs. The first 22 pairs are numbered 1 through 22 and the 23rd "pair" are the sex chromosomes (X and Y). Based on their shape, chromosomes are said to have two "arms", a short arm called "p" and a long arm called "q".
Having 22q11.2 duplication does not mean you have a medical condition. In fact, some people with the duplication do not have any symptoms. However, people who have been identified as having this duplication by genetic testing often have other health or developmental problems which led to the testing (but are not necessarily caused by the duplication). Because this is a relatively rare chromosome difference, most doctors are not familiar with it.
Prior to 2006, a 22q11.2 duplication was only reported after very specialized genetic tests called Fluorescence in situ hybridization (FISH) or Multiplex ligation-dependent probe amplification (MLPA) for that area on chromosome 22 were done. After 2006, doctors started using a new test called "array comparative genomic hybridization" or chromosomal microarray that was able to the find very small changes in chromosomes like the 22q11.2 duplication more routinely. Although many things have been learned about 22q11.2 duplications, it is still unclear in 2016 why having an extra piece of material in 22q11.2 affects some people’s health and development but not others, or if it causes any problems at all. Complicating the question is the knowledge that most information we have on the 22q11.2 duplication was learned from people searching for a cause for health problems and developmental delays. This makes it unclear if a 22q11.2 duplication is a main cause of birth defects and developmental delays, a common change that doesn’t cause problems, or a partial cause of health problems that needs to be present with other genetic changes before problems happen. Given the range of health problems, treatment for people with 22q11.2 duplication should be very specific to the person’s needs.
Working with a doctor or genetic counselor familiar with 22q11.2 duplication can very helpful in understanding the implications (if any) of 22q11.2 duplication for a specific person and develop a good monitoring and treatment plan. Several resources for locating a genetics professional in your community are available online such as the National Society of Genetic Counselors. Genetic counselors can be found on the National Society of Genetic Counselors website.You can search by location, name, area of practice/specialization, and/or ZIP Code. The Genetic and Rare Diseases Information Center (GARD) , a service of the National Institutes of Health, provides a guide to finding specialists in particular genetic and rare conditions. (https://rarediseases.info.nih.gov/resources/pages/25/how-to-find-a-disease-specialist).
There are several support groups that were created to connect, help, and provide information for people living with 22q11.2 duplication and their families. One such group is the support group Chromosome 22 Central (also called C22C) that can be found at the website http://www.c22c.org/. This group supports patients with all different types of chromosome 22 changes from 22q11.2 duplication syndrome to unique changes in chromosome 22 only seen a very small amount of people. They provide basic information on their website, but their primary mission is connecting patients and families with each other to learn from one another. The International 22q11.2 Foundation, Inc. focuses on support and advocacy for individuals and families affected by a duplication OR deletion in the 22q11.2 region (http://www.22q.org/about-22q/).
22q11.2 duplication may be called by several different names including 22q11.2 microduplication, 22q11.2 common 3 Mb duplication, and 22q11.2 1.5 Mb proximal tandem duplication. A geneticist can tell you if you have the 1.5 or 3 Mb duplication (or somewhere in between). At this point in time, there doesn’t seem to be much difference between the 1.5 and the 3 Mb duplication aside from size and number of genes involved.
Sometimes you will see the word "syndrome" following the 22q11.2 duplication. Strictly speaking, some geneticists think this is incorrect. This is because a "syndrome" is a recognizable pattern of clinical features (usually physical, medical, or intellectual differences) with the same underlying cause. Since it is still unclear whether the 22q11.2 duplication causes medical problems (and if so, which ones), it should not be referred to as a syndrome.
A medical geneticists can be found by asking your doctor for a referral or looking on the American College of Medical Geneticists website. Genetic counselors can be found on the National Society of Genetic Counselors website.
It is difficult to know how common 22q11 duplications are because the testing that looks for the very small change is usually only offered to people with a history of learning delays and/or birth defects. One recent study analyzed 7,000 cases referred for testing because of a history of developmental delay and the 22q11 duplication was identified in ten people which provided a 1:700 prevalence in a high risk population. Another recent study identified the 22q11 duplication in 1:320 people out of a sample size of 15,000 individuals referral for testing also because of a history of developmental delays. Both of these studies are limited in that they are only testing people with changes in development which creates an ascertainment bias. Given that we know that family members can also have 22q11 duplications and have typical development, it is unclear how common the 22q11 duplication is in the general population.
It is difficult to know how common 22q11.2 duplications are because the testing that looks for the very small change is usually only offered to people with a history of learning delays and/or birth defects. One recent study analyzed 7,000 cases referred for testing because of a history of developmental delay and the 22q11.2 duplication was identified in ten people which provided a 1:700 prevalence in a high risk population. Another recent study identified the 22q11.2 duplication in 1:320 people out of a sample size of 15,000 individual’s referral for testing also because of a history of developmental delays. Both of these studies are limited in that they are only testing people with changes in development which creates an ascertainment bias. Given that we know that family members can also have 22q11.2 duplications and have typical health and development, it is unclear how common the 22q11 duplication is in the general population.
Frequently Asked Questions About 22q11.2 duplication syndrome
Why do some people with a 22q11.2 duplication have symptoms and others do not?
The effects of having a 22q11.2 duplication are highly variable, even within the same family. Doctors and scientists are still uncertain whether the 22q11.2 duplication causes any health problems at all. It could be that other genetic factors must combine with a 22q11.2 duplication before health problems occur. Most of the available research into people with a 22q11.2 duplication is from people who came to attention because they had developmental delays or a serious health problem. This means that at the moment we can’t be sure about cause and effect with a 22q11.2 duplication and we can’t predict the effect a 22q11.2 duplication will have on an individual, if any. Individuals with a 22q11.2 duplication who are interested in helping researchers learn more about the impact of 22q11.2 duplication might consider joining a study. Research opportunities are often available by connecting with support groups such as Chromosome 22 Central (C22C) Support for Disorders of Chromosome 22 group which gathers study information in one easily accessible webpage (http://www.c22c.org/research.htm) and The International 22q11.2 Foundation, Inc. (http://www.22q.org/news-updates/opportunities-for-families/).
Who else in the family should be tested for a 22q11.2 duplication?
The 22q11.2 duplication is new or "de novo" in a person about 30% of the time and passed down (inherited) from a parent about 70% of the time. When it is inherited and found for the first time in a family, most parents are completely unaware that they had the extra bit of chromosome 22 until they were tested after their child was found to have the duplication. Like other chromosome deletions or duplications present on one of the numbered chromosomes (1-22, not on the X or Y chromosome), anyone who has a duplicated piece of chromosome 22 has a 50% chance of passing it on to their children. This means that they also have a 50% chance of having a child without the duplication. This form of inheritance is called "autosomal dominant". Having said this, it is not possible to guess ahead of time how mildly or severely a baby with the duplication will be affected – or whether they will be affected at all. A genetic counselor can help create a family tree or genetic pedigree and identify the individuals who are most likely to have the 22q11.2 duplication and should be tested. Genetic counselors can be found by asking your doctor for a referral. Genetic counselors can also be found on the National Society of Genetic Counselors website.
Where do I find other patients and families living with 22q11.2 duplication?
There are several support groups that were created to connect and introduce patients living with 22q11.2 duplication and their families. One such group is the support group Chromosome 22 Central (also called C22C) that can be found at the website http://www.c22c.org/. This group supports patients with all different types of chromosome 22 changes from 22q11.2 duplication syndrome to unique changes in chromosome 22 only seen a very small amount of people. They provide basic information on their website, but their primary mission is connecting patients and families with each other to learn from one another. The International 22q11.2 Foundation, Inc. focuses on support and advocacy for individuals and families affected by a duplication OR deletion in the 22q11.2 region (http://www.22q.org/about-22q/).
Other broader chromosomal focused support groups include Chromosome Disorder Outreach ([link url="www.chromodisorder.org/” target=”_blank”>www.chromodisorder.org/) and UNIQUE (http://www.rarechromo.org/). These groups also work with patients and families living with 22q11.2 duplication syndrome as well as patients with many other different types of chromosome changes by supporting, informing, and networking with anyone affected by a rare chromosome disorders and with any interested professionals.
What specialist doctors should I see as I have 22q11.2 duplication syndrome?
Having 22q11.2 duplication, or extra genetic material on the long arm of chromosome 22, is not a medical condition. However, people who have been identified as having this duplication by genetic testing often have other health or developmental problems which led to the testing (but are not necessarily caused by the duplication). If you or your child has been identified as having 22q11.2 duplication, you should meet with a medical geneticist to get the most up-to-date information about the duplication and possible associated medical conditions. A medical geneticists can be found by asking your doctor for a referral or looking on the American College of Medical Geneticists website. Genetic counselors can be found on the National Society of Genetic Counselors website.
What is the different between 22q11.2 duplication and 22q11 deletion?
People with the typical 22q11.2 duplication have an added EXTRA bit of chromosome 22, while those with the typical 22q11.2 deletion are MISSING the same piece of chromosome 22 that is extra in the duplication. The genes affected are the same, but the copy number is different. People with the duplication have THREE copies of those genes, and people with the deletion have only ONE copy (most people have 2 copies). Features and health problems of people with the 22q11.2 deletion may vary in severity but may include: specific facial features, immune system problems, cleft palate, heart problems, breathing problems, kidney problems, abnormal platelets, bone development problems, developmental disabilities, and an increased risk for psychiatric issues later in life. The features of people with a 22q11.2 duplication are much more variable, even among members of the same family. However, many people with the duplication have no apparent physical or learning difficulties or disabilities. The earliest studies on people with the 22q11.2 duplication were done on people with health problems similar to 22q11.2 deletion syndrome, because the same genetic tests can detect both the deletion and the duplication. Therefore, it was initially thought that the 2 conditions had similar features. More recent studies have shown that only a minority of people with the duplication have medical problems similar to the deletion syndrome.
What is 22q11.2 duplication?
22q11.2 duplication means that there is a very small extra piece of genetic material on the long arm of the 22nd chromosome. Most often this extra piece is a copy (or duplicate) of the piece next to it.
Chromosomes are found in most cells of our bodies and contain the genetic information or blueprints for our body to grow and function. These chromosomes come in 23 pairs. The first 22 pairs are numbered 1 through 22 and the 23rd "pair" are the sex chromosomes (X and Y). Based on their shape, chromosomes are said to have two "arms", a short arm called "p" and a long arm called "q".
Having 22q11.2 duplication does not mean you have a medical condition. In fact, some people with the duplication do not have any symptoms. However, people who have been identified as having this duplication by genetic testing often have other health or developmental problems which led to the testing (but are not necessarily caused by the duplication). Because this is a relatively rare chromosome difference, most doctors are not familiar with it.
Prior to 2006, a 22q11.2 duplication was only reported after very specialized genetic tests called Fluorescence in situ hybridization (FISH) or Multiplex ligation-dependent probe amplification (MLPA) for that area on chromosome 22 were done. After 2006, doctors started using a new test called "array comparative genomic hybridization" or chromosomal microarray that was able to the find very small changes in chromosomes like the 22q11.2 duplication more routinely. Although many things have been learned about 22q11.2 duplications, it is still unclear in 2016 why having an extra piece of material in 22q11.2 affects some people’s health and development but not others, or if it causes any problems at all. Complicating the question is the knowledge that most information we have on the 22q11.2 duplication was learned from people searching for a cause for health problems and developmental delays. This makes it unclear if a 22q11.2 duplication is a main cause of birth defects and developmental delays, a common change that doesn’t cause problems, or a partial cause of health problems that needs to be present with other genetic changes before problems happen. Given the range of health problems, treatment for people with 22q11.2 duplication should be very specific to the person’s needs.
Working with a doctor or genetic counselor familiar with 22q11.2 duplication can very helpful in understanding the implications (if any) of 22q11.2 duplication for a specific person and develop a good monitoring and treatment plan. Several resources for locating a genetics professional in your community are available online such as the National Society of Genetic Counselors. Genetic counselors can be found on the National Society of Genetic Counselors website.You can search by location, name, area of practice/specialization, and/or ZIP Code. The Genetic and Rare Diseases Information Center (GARD) , a service of the National Institutes of Health, provides a guide to finding specialists in particular genetic and rare conditions. (https://rarediseases.info.nih.gov/resources/pages/25/how-to-find-a-disease-specialist).
There are several support groups that were created to connect, help, and provide information for people living with 22q11.2 duplication and their families. One such group is the support group Chromosome 22 Central (also called C22C) that can be found at the website http://www.c22c.org/. This group supports patients with all different types of chromosome 22 changes from 22q11.2 duplication syndrome to unique changes in chromosome 22 only seen a very small amount of people. They provide basic information on their website, but their primary mission is connecting patients and families with each other to learn from one another. The International 22q11.2 Foundation, Inc. focuses on support and advocacy for individuals and families affected by a duplication OR deletion in the 22q11.2 region (http://www.22q.org/about-22q/).
What clinical research is happening for people with 22q11.2 duplication syndrome?
Research opportunities are often available by connecting with support groups such as C22C which gather study information in one easily accessible webpage (http://www.c22c.org/research.htm) and The International 22q11.2 Foundation, Inc. (http://www.22q.org/news-updates/opportunities-for-families/). In addition the clinicaltrials.gov website allows one to search for clinical trials for 22q11.2 duplication. As of April 2019, there were no clinical trials specifically for 22q11.2 duplication.
What causes a 22q11.2 duplication?
Chromosome 22 is one of the 23 pairs of chromosomes in the body’s cells that carry the genetic material that tells bodies how to grow and function. In our cells, the genetic material is called DNA and it has a ladder-like structure, with the ladder’s rungs formed from chemicals called nucleotide base pairs (bp). The size of the tiny extra bit of DNA found when there is a 22q11.2 duplication is measured in number of base pairs. In most cases, the duplicated genetic material consists of a sequence of about 3 million base pairs, also written as 3 megabases (Mb). There are millions of base pairs on a chromosome, so the numbers’ names are usually shortened. One million base pairs is called a megabase, and written as 1 Mb. Most people have a 22q11.2 duplication that is between 1.5 and 3 Mb in size. The 3 Mb duplicated region contains 30 to 40 genes. Typically, the extra bit starts around 17 Mb and ends around 20 Mb. Some people have smaller duplications, about 1.5 Mb in size. Some people have larger duplications, from 4 to 6 Mb, but these are rare. People with a 22q11.2 duplication should have a genetic testing report that explains the size of their duplication and what genes are involved. The best people to help find their report or help determine if the 22q11.2 duplication is the most likely explanation for that person’s changes in development are medical geneticists or genetic counselors. A medical geneticists can be found by asking your doctor for a referral or looking on the American College of Medical Geneticists website. Genetic counselors can be found on the National Society of Genetic Counselors website.
What are the main symptoms of 22q11.2 duplication?
Having 22q11 duplication syndrome or extra genetic material on the long arm of chromosome 22 can cause changes in the formation of the heart leading to heart defects, to weak or "floppy" muscle tone (hypotonia), problems developing the roof of the mouth (the soft palate) creating a problem called velopharyngeal insufficiency (opening in the soft palate of the mouth that can affect speech), hearing loss, slow physical growth, and sometimes developmental delays and learning problems. However, some people with the same extra information on chromosome 22 have no detectable health problems at all. This difference or variability in health problems was found when doctors tested the parents, brothers, and sisters of individuals affected with 22q11 duplications and found that may of them did not have any health problems. 22q11 duplication syndrome was first reported in 2003 with the availability of a new test called array comparative genomic hybridization (or chromosomal microarray) was able to the very small changes reported in 22q11 duplication syndrome. Although many things have been learned about this syndrome, it is still unclear in 2016 why having an extra piece of material in 22q11 affects some people’s health and development but not others. since the 22q11 duplication is mainly found after a testing is done during the search to find a cause for health problems and developmental delays, it is unclear if this genetic change is actually the main cause of the birth defects and developmental delays. Given the range of health problems, treatment for people with 22q11 duplication should be very specific to the person’s needs and a plan created after checking for symptoms seen more frequently with a 22q11 duplication. Treatments may range from heart surgery to educational program tailored for an individual’s needs.
To find a medical professional nearby who can discuss health issues and treatment plans, a medical geneticists can be found by asking your doctor for a referral or looking on the American College of Medical Geneticists website.
What are the first steps after an initial diagnosis of 22q11.2 duplication syndrome?
After someone is diagnosed with 22q11 duplication syndrome, the first steps are often testing the parents to figure out if the duplication was passed down from a parent. This information helps doctors learn more about the chance that other family members have the change. Since having a 22q11 duplication or extra genetic material on the long arm of chromosome 22 can cause changes in the formation of the heart leading to heart defects, to weak or "floppy" muscle tone (hypotonia), problems developing the roof of the mouth (the soft palate) creating a problem called velopharyngeal insufficiency (opening in the soft palate of the mouth that can affect speech), hearing loss, slow physical growth, and sometimes developmental delays and learning problems next steps are often to look for each of these health issues so that they can be treated appropriately.
Even though some people with the same extra information on chromosome 22 have no detectable health problems, it is important to actually look for each of the issues and not just assume they are not present based on a brief physical exam. There can be a large difference or variability in health problems found within the same family. Although many things have been learned about this syndrome, it is still unclear in 2016 why having an extra piece of material in 22q11 affects some people’s health and development but not others. Given the range of health problems, treatment for people with 22q11 duplication should be very specific to the person’s needs and a plan created after checking for symptoms seen more frequently with a 22q11 duplication. Treatments may range from heart surgery to educational program tailored for an individual’s needs. These needs may change over time, so it is important to work with a doctor who understand the need for monitoring.
Another first step for families and individuals affected by a 22q11 duplication may be reaching out to a support group to access their knowledge, resources, and support. There are several active support groups which work with individuals with the 22q11 duplication including:
–The Chromosome 22 Central (C22C) Support for Disorders of Chromosome 22;
–The International 22q11.2 Foundation, Inc;
–Chromosome Disorder Outreach;
–UNIQUE 22q11.2 duplications.
Is there newborn screening for 22q11.2 duplication syndrome?
As of June 2016, chromosomal changes including the 22q11 duplication are not on the Recommended Uniform Screen Panel (RUSP). The RUSP is created by the Health Resources and Services Administration, and states use this list to guide what conditions they screen for on newborn screening. It should be noted that if a baby has health problems, doctors may order a chromosome analysis (karyotype) and possibly array genomic hybridization (chromosomal microarray) test. Of those two tests, only the chromosomal microarray would be able to detect the 22q11 duplication. Genetic testing is most often ordered by genetic professionals like medical geneticists or genetic counselors. Geneticists can be found by asking your doctor for a referral or looking on the American College of Medical Geneticists website. Genetic counselors can be found on the National Society of Genetic Counselors website.
Is there more than one test for 22q11.2 duplication syndrome?
A 22q11.2 duplication is a genetic change in which there is an extra copy of a very small piece of chromosome 22. As the 22q11.2 duplication so tiny, it is not detectable by routine chromosome analysis (also called karyotyping.) Most individuals with 22q11.2 duplication are identified either by something called array genomic hybridization (chromosomal microarray) testing or by multiplex ligation-dependent probe amplification (MLPA) testing for the 22q11.2 duplication. Both of these tests are performed with blood work but can be diagnosed in pregnancy using cells from the placenta or the amniotic fluid. Testing for the 22q11.2 duplication is most often ordered by a medical geneticist or genetic counselor. To find a medical professional nearby who can discuss information and testing, a listing of medical geneticists can be found by asking your doctor for a referral or looking on the American College of Medical Geneticists website. Genetic counselors can be found on the National Society of Genetic Counselors website.
Is there a useful guide to 22q11.2 duplication that focuses on helpful tips for parents?
The UNIQUE support group has created an excellent guide to 22q11 duplication that provides detailed information on everything from explanations of health problems to best practices for individualized educational plans at different ages. This guide is available from the UNIQUE website in a pdf formation here: http://www.rarechromo.org/information/Chromosome%2022/22q11.2%20duplications%20FTNW.pdf
Is there a cure for 22q11.2 duplications?
There is not a specific cure or treatment for 22q11.2 duplication syndrome; however, after someone is diagnosed with 22q11.2 duplication syndrome, the first steps are treating individuals symptoms such as surgery for heart defects, physicial therapy to improve weak or "floppy" muscle tone (hypotonia), speech therapy for individuals with speech delays, special feeding tools for infants with a problem called velopharyngeal insufficiency (opening in the soft palate of the mouth), hearing aids for hearing loss, and an individualized education or learning plan that often begins with early intervention therapies. As there can be a large difference or variability in health problems caused by 22q11.2 duplications some individuals will not require any therapy or treatments.
Given the range of health problems, treatment for people with 22q11.2 duplication should be very specific to the person’s needs and a plan created after checking for symptoms seen more frequently with a 22q11.2 duplication. These needs may change over time, so it is important to work with a doctor who understand the need for monitoring.
Families and individuals affected by a 22q11.2 duplication may learn more about the best therapy options by reaching out to a support group to access their knowledge, resources, and support. There are several active support groups which work with individuals with the 22q11 duplication including:
–The Chromosome 22 Central (C22C) Support for Disorders of Chromosome 22;
–The International 22q11.2 Foundation, Inc;
–Chromosome Disorder Outreach;
–UNIQUE 22q11.2 duplications.
How is 22q11.2 duplication syndrome inherited?
The 22q11.2 duplication is new or "de novo" in a person about 30% of the time and passed down (inherited) from a parent about 70% of the time. When it is inherited and found for the first time in a family, most parents are completely unaware that they had the extra bit of chromosome 22 until they were tested after their child was found to have the duplication. Like other chromosome deletions or duplications present on one of the numbered chromosomes (1-22, not on the X or Y chromosome), anyone who has a duplicated piece of chromosome 22 has a 50% chance of passing it on to their children. This means that they also have a 50% chance of having a child without the duplication. This form of inheritance is called "autosomal dominant". Having said this, it is not possible to guess ahead of time how mildly or severely a baby with the duplication will be affected – or whether they will be affected at all. A genetic counselor can help create a family tree or genetic pedigree and identify the individuals who are most likely to have the 22q11.2 duplication. Genetic counselors can be found on the National Society of Genetic Counselors website.
How do I get tested for a 22q11.2 duplication?
A 22q11.2 duplication is a genetic variation in which there is an extra copy of a small piece of chromosome 22. The duplication is found near the middle of the chromosome at a place called q11.2. Because the extra bit is very tiny indeed, you will sometimes see it called a microduplication. As the 22q11.2 Duplication so tiny, it is not detectable by routine chromosome analysis (also called karyotyping.) Most individuals with 22q11.2 duplication are identified with a test called array genomic hybridization (chromosomal microarray) or by multiplex ligation-dependent probe amplification (MLPA) testing for the 22q11.2 duplication. Both of these tests are performed with blood work but can be diagnosed in pregnancy using cells from the placenta or the amniotic fluid. Testing for the 22q11.2 duplication is most often done by a medical geneticist or genetic counselor. To find a medical professional nearby who can discuss information and testing, a listing of medical geneticists can be found at the American College of Medical Genetics website and genetic counselors can be found on the National Society of Genetic Counselorswebsite.
How do I find a center of excellence in 22q11.2 duplication syndrome?
Although there are very few doctors who specialize in 22q11.2 duplication, the best way to find a healthcare provider aware of 22q11.2 duplication and treatment recommendations is to reach out to your local medical geneticist and/or genetic counselor.
A medical geneticists can be found by asking your doctor for a referral or looking on the American College of Medical Geneticists website. Genetic counselors can be found on the National Society of Genetic Counselors website.
You may also reach out to one of the support groups focusing on chromosome 22 related conditions to ask for healthcare provider recommendations.
–The Chromosome 22 Central (C22C) Support for Disorders of Chromosome 22;
–The International 22q11.2 Foundation, Inc;
–Chromosome Disorder Outreach;
–UNIQUE 22q11.2 duplications.
How common is a 22q11.2 duplication?
It is difficult to know how common 22q11 duplications are because the testing that looks for the very small change is usually only offered to people with a history of learning delays and/or birth defects. One recent study analyzed 7,000 cases referred for testing because of a history of developmental delay and the 22q11 duplication was identified in ten people which provided a 1:700 prevalence in a high risk population. Another recent study identified the 22q11 duplication in 1:320 people out of a sample size of 15,000 individuals referral for testing also because of a history of developmental delays. Both of these studies are limited in that they are only testing people with changes in development which creates an ascertainment bias. Given that we know that family members can also have 22q11 duplications and have typical development, it is unclear how common the 22q11 duplication is in the general population.
Does the 22q11.2 duplication cause autism?
Some researchers in the autism field claim that having 22q11.2 duplication may increase the chance for an individual to develop autism. In a 2016 study, researchers gave 20 children with 22q11.2 duplications one or both of the gold-standard diagnostic tests for autism and found that five of them were diagnosed with autism. However, these children were already identified as having developmental and/or medical problems, so they were likely at higher risk of having autism anyway. The researchers suggested that 14- 25 percent of people with the duplication have the condition. However, this study was biased because they only tested people already identified as having 22q11.2 duplication. Thus, this is likely an over-estimate of the actual chances of developing autism in an otherwise healthy person with 22q11.2 duplication. More research in an unbiased sample of people with the 22q11.2 duplication are needed to clarify this.
Do people with 22q11.2 duplications have psychiatric disorders?
In March 2017 a large Danish population study looked at individuals in the Danish healthcare system with 22q11.2 duplication. In this study population, individuals who had this duplication were at increased risk for psychiatric disorders. The study concludes that individuals with a 22q11.2 duplication should be monitored and referred to a mental health professional if needed.
Are there support groups for people living with 22q11.2 duplication syndrome and their families?
There are several support groups that were created to connect, help, and provide information for people living with 22q11.2 duplication and their families. One such group is the support group Chromosome 22 Central (also called C22C) that can be found at the website http://www.c22c.org/. This group supports patients with all different types of chromosome 22 changes from 22q11.2 duplication syndrome to unique changes in chromosome 22 only seen a very small amount of people. They provide basic information on their website, but their primary mission is connecting patients and families with each other to learn from one another. The International 22q11.2 Foundation, Inc. focuses on support and advocacy for individuals and families affected by a duplication OR deletion in the 22q11.2 region (http://www.22q.org/about-22q/).
Other broader chromosomal focused support groups include Chromosome Disorder Outreach ([link url="www.chromodisorder.org/” target=”_blank”>www.chromodisorder.org/) and UNIQUE (http://www.rarechromo.org/). These groups also work with patients and families living with 22q11.2 duplication syndrome as well as patients with many other different types of chromosome changes by supporting, informing, and networking with anyone affected by a rare chromosome disorders and with any interested professionals.
Are there other names for a 22q11.2 duplication syndrome?
22q11.2 duplication may be called by several different names including 22q11.2 microduplication, 22q11.2 common 3 Mb duplication, and 22q11.2 1.5 Mb proximal tandem duplication. A geneticist can tell you if you have the 1.5 or 3 Mb duplication (or somewhere in between). At this point in time, there doesn’t seem to be much difference between the 1.5 and the 3 Mb duplication aside from size and number of genes involved.
Sometimes you will see the word "syndrome" following the 22q11.2 duplication. Strictly speaking, some geneticists think this is incorrect. This is because a "syndrome" is a recognizable pattern of clinical features (usually physical, medical, or intellectual differences) with the same underlying cause. Since it is still unclear whether the 22q11.2 duplication causes medical problems (and if so, which ones), it should not be referred to as a syndrome.
A medical geneticists can be found by asking your doctor for a referral or looking on the American College of Medical Geneticists website. Genetic counselors can be found on the National Society of Genetic Counselors website.
Are there any awareness activities for 22q11.2 duplication?
The International 22q11.2 Foundation has several awareness events. Events associated with their November 22q11.2 awareness campaign and other awareness activities can be found on the awareness page of their website.
