Genetics Fact Sheet – 16p11.2 Deletion For more detailed information, you may call the Simons VIP Genetic Counselors @ 888-493-6682 or visit our
website (www.SimonsVIPConnect.org) and click on the ‘About 16p’ tab.
What does it mean to have a 16p11.2 deletion?
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Genes provide our body’s instructions and are carried within structures called
chromosomes. Sometimes individuals are born with extra or missing sections of
chromosomes. A loss or gain of part of a chromosome can impact health, learning, and
behavior. The effects may vary based on the location and size of the changes, and the
importance of genes there.
o Individuals with 16p11.2 deletions are missing a specific section in one of their
two chromosome 16’s.
How was my child’s deletion found?
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Your child had a genetic test called “array comparative genomic hybridization” (arrayCGH, also known as microarray). A microarray looks closely at all of the genetic
material on a person’s chromosomes. Microarray is a new and very sensitive test that can
identify any small missing or extra pieces of a chromosome. This test identified your
child’s 16p11.2 deletion.
What type of genetic test does a parent need to find out if they carry the same deletion?
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Each parent needs to have a test called FISH (fluorescence in situ hybridization). This test
is a more targeted one than the microarray. FISH looks specifically at the 16p11.2 area
only. FISH uses a very small chemical that glows brightly when it detects the 16p11.2
region on a chromosome. A scientist uses a special microscope to look at the
chromosome and see how many bright spots are present. When a person has a deletion,
only one bright spot is seen instead of two (one on both chromosomes).
How common is it to have a 16p11.2 deletion?
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A loss or gain of material from 16p11.2 is increasingly recognized as one of the most
common structural chromosome disorders. The 16p11.2 deletion has been found in
around 1:100 people with autism; in around 1:1000 people with a language or psychiatric
disorder; and in around 1 in 3,300 people in the general population (Weiss 2008; Bijlsma
2009).
What are the most common symptoms experienced by people with a 16p11.2 deletion?
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Children and adults with the deletion have exhibited a wide range of symptoms, which
have been reported to include speech delay, developmental delay, behavior problems,
obesity, and others. Some individuals do not experience any symptoms and others can
have mild to severe symptoms. Several scientific articles have been published with
results from research about people with this deletion. Summaries of these articles are
available on the Simons VIP website.
Could I have another child with a 16p11.2 deletion?
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Your chance of having another child with a 16p11.2 deletion depends on whether or not
you or your partner also carries the 16p11.2 deletion.
o When both parents have normal chromosomes, the chance of having another
affected child is certainly very low, but still higher than for parents who never had
a child with 16p11.2 deletion.
o If either parent has the same 16p11.2 deletion as the child, that parent has a 50%
(1 out of 2) chance of passing it on in each pregnancy.
 Prenatal diagnosis is technically possible as early as 11 weeks gestation.
However, it isn’t possible to predict how mildly or severely any child will
be affected.
Could my child have similarly affected children?
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In each pregnancy, someone with the deletion has a 50% (1 out of 2) chance of passing it
on and a 50% (1 out of 2) chance of having a child without it.