Familial Adenomatous Polyposis (FAP): Children’s leaflet

Familial Adenomatous
Polyposis (FAP):
Children’s leaflet

Patient information leaflet

This booklet has been written for people attending the clinical
genetics service with a personal or family history of familial
adenomatous polyposis (FAP).

What is familial adenomatous polyposis (FAP)?

FAP is a condition that runs in families, hence the term familial. The rest of
the name comes from the fact that little lumps, called polyps, grow in large
numbers on the lining of the bowel.

What is a polyp?

Polyps are non-cancerous lumps, which grow on the lining of the bowel.
There are many different kinds of polyps, which grow in a number of places
in the body, but the polyps that are seen in the bowel of people with FAP are
called adenomas. Bowel polyps are also found in many people without FAP,
but usually in small numbers.
A diagnosis of FAP is made when large numbers of adenomas are found
in the large bowel, which is the end of the long food pipe of the body,
called the colon and rectum. These areas of the body are highlighted in the
diagram opposite.

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Stomach

Small
intestine
Colon

Rectum Looking inside the
Polyps seen colon, many small
from the side. polyps can be seen.

The large bowel (colon and rectum) showing polyps in the colon

Causes

FAP is usually inherited, but sometimes a person may be the first member of
their family to develop the condition.

Our bodies contain thousands of sets of instructions called genes that tell our
body how to function. They make each of us individual; for example, what
colour to make our eyes or how tall we will be. There are also genes that are
involved in repairing the damage to our bodies that occurs during normal
daily life.

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You may hear many different words used to describe a gene that is not
working properly. A gene may be said to be faulty, altered or changed. The
technical term is a mutation. This means that the instruction the gene sends
to the body may be different, just as a spelling mistake may change the
meaning of a word.

How are these genes inherted?

We all have two copies of our genes; we get one copy from our mum, the
other copy from our dad. Some genes are so important that you need both
copies working correctly to be healthy. One faulty copy of these important
genes can cause disease to develop.
When we have children, we pass just one of each copy on; the other comes
from the other parent. If someone has an gene mutation, they will also have
a normal copy. So each of his or her children has a one in two (50%) chance
of inheriting the gene mutation.

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When do polyps develop?

For people who carry a gene mutation associated with FAP, polyps usually
start to develop in their early teens. This is why bowel checks usually begin
between ten and 14 years of age.

How do we look for polyps?

The bowel is examined using a test called a colonoscopy. A long bendy tube
(colonoscope) is carefully passed through the anus into the back passage
(rectum) and into the large bowel. The colonoscope has a bright light on the
end, which the doctor uses to get a clear view of the lining of the bowel.

It is necessary to prepare (empty) the bowel before the test, so the doctor is
able to see clearly. This usually involves taking medicine the day before.
Anyone who may have gene mutation should be tested for polyps once a
year. Most people develop polyps by the age of 30, and with every passing
year without polyps, the chances of having a gene mutation go down. Of
course, if you have a negative gene test this examination won’t be necessary.

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Treatment

If polyps are found during a colonoscopy test, the doctor will usually remove
the polyp there and then and look at it under the microscope. If they are
harmless and few in number, it may be OK to continue with regular checks
on the bowel.
If one of the polyps gets bigger or there are many polyps in total, the doctor
will recommend an operation. This operation may take place at the age of 16
to 17 years or later, depending on the results of the screening checks.

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Useful words

Adenoma (Adenomatous)
There are different kinds of polyp; this describes how the polyps in FAP look
under the microscope.
APC
The name scientists give the FAP gene. It stands for adenomatous polyposis
coli.
CHRPE (congenital hypertrophy of retinal pigment epithelium)
Harmless black marks on the back of the eye.
Colonoscopy
Like sigmoidoscopy, but the whole colon is examined.
Dominant
Occurs when there is a one in two (50%) chance of passing on a condition.
Familial
A condition which runs in families.
Gene
One of the chemical recipes which control the working of the body.
Large bowel
The end section of the intestine or food pipe, made up of the colon and
rectum.
Polyp
A non-cancerous lump on the bowel wall.
Sigmoidoscopy
A short tube with a light at the end is passed into the rectum and the last
part of the colon to look for polyps.

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The team involved in your care is:
Consultant:
Tel No:
Genetic Counsellor:
Tel No:

Further information

If you have any questions or would like more advice about FAP in children,
please contact us at:
Wessex Clinical Genetics Service
Princess Anne Hospital
Coxford Road
Southampton
SO16 5YA
Telephone: 023 8079 6170
Website: www.wcgs.nhs.uk

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Notes

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Notes

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