Download Angleman Syndrome - Birmingham Women`s Hospital

What is the chance of having
another affected child?
If you have a child with Angelman
syndrome, in most cases, the risk of
having a second affected child is low
(about 1%). However, the risk may be
higher than this in a few families.
The chance of recurrence and also the
possibility of genetic testing in a future
pregnancy can be discussed at the
genetics clinic.
Treatment of Angelman
syndrome
Unfortunately, there is no cure for
Angelman syndrome. Early diagnosis
allows for input from various specialist
services to helps development and
learning. Further research may improve
treatment in the years to come.
For more information
There is a support group that provides
information packs and has a parent
helpline:
Birmingham Women's
NHS Foundation Trust
A.S.S.E.R.T.
PO Box 4962
Nuneaton
Kent
CV11 9FD
Parents Helpline: 0300 999 0102
Acknowledgment
With thanks to Guy’s and St Thomas’
NHS Foundation Trust, London
Angelman Syndrome
An information leaflet for
patients and families
If you need more advice about any
aspect of Angelman syndrome please
contact:
Clinical Genetics Unit
Birmingham Women’s
NHS Foundation Trust
Mindelsohn Way, Edgbaston
Birmingham B15 2TG
Telephone: 0121 627 2630
Fax: 0121 627 2618
Email: [email protected]
Reference Number: GG 24
Author: Dr Jenny Morton
Consultant Clinical Geneticist
Reviewed: June 2014 Next review: June 2017
This is a no smoking hospital
What is Angelman syndrome?
Angelman syndrome is a rare genetic
disorder. The condition affects both
boys and girls. People with Angelman
syndrome are described as having severe
global developmental delay, significant
speech impairment, unsteady gait and
a happy disposition, with frequent,
unprovoked laughter. Affected people
usually have a small head circumference
and epilepsy.
What are Genes and
Chromosomes?
Chromosomes are condensed strings
of DNA. We have 46 chromosomes in
most cells in our body, arranged in pairs.
We normally inherit one of each of the
pairs from our mother and one from our
father.
Each chromosome carries hundreds of
genes. Genes are unique DNA sequence
that determine a particular characteristic
or function. We have more than 25,000
different genes. The combination of the
genes we inherit makes us all individual.
What causes Angelman
syndrome?
Angelman syndrome is due to a fault/
alteration involving the Angelmans
syndrome critical region (ASCR) on
chromosome 15 and there are a number
of ways in which this region can be
affected including:
• A missing piece of genetic material
(deletion) on the maternal
chromosome 15 i.e. the one passed
on by the mother. This is the most
common cause of Angelman syndrome
(70% of cases).
Other features that become apparent in
time include:
• An alteration (like a spelling mistake)
in a specific Angelman gene called
UBE3A (10% cases).
Most children with Angelman syndrome
start walking between 2½ and 6 years
and are unsteady on their feet. They
have a happy disposition, unprovoked
outbursts of laughter and absence of
almost all speech. Their non-verbal
communication is however much better.
Some learn sign language and use
communication devices. They are usually
happy, affectionate and sociable.
• Both copies of chromosome 15 are
inherited from father (7% of cases)
instead of there being one copy from
each parent. This is called chromosome
15 uniparental disomy.
• The copy of the Angelmans gene from
mother is “switched off” (3%). This is
called an imprinting defect.
• A complex chromosome rearrangement
involving chromosome 15 (<1% cases).
• In 10% of cases we are unable to find a
genetic cause for Angelman syndrome.
• Severe Learning disability/difficulties
• A similar facial appearance to other
children with Angelman syndrome
Many children have sleep difficulties and
hyperactivity, although these tend to
improve with age. Angelman syndrome
does not affect development at puberty
or fertility.
Infancy and Childhood
Symptoms and Signs
Angelman syndrome in
Adulthood
• Feeding problems
• Delayed developmental milestones
• Unusual movements including fine
tremors and jerky limb movements
• Epilepsy (seizures if they occur often
start in the first 2 or 3 years of life)
• Hand flapping
• Low muscle tone
• A smaller than normal head size
• Light skin and hair colour
Adults with Angelman syndrome are
not able to live independently. Their
general health is usually good, although
some will require long term treatment
for their epilepsy. The diagnosis does
not seem to shorten life span. A woman
with Angelman syndrome can pass the
condition on to her children.