The Cause
Williams Syndrome (WS) is caused
by a microdeletion on chromosome 7. This means
a small segment of genetic information is missing.
This includes the gene for elastin which gives
elasticity to the skin, joints and blood vessels.
It rarely occurs twice in one family but the
individual who has Williams Syndrome has a 50%
chance of passing it on to his or her children.
It is a rare genetic condition first described
by Dr J C P Williams at Greenlane Hospital, Auckland,
New Zeland, in 1961. It can occur in all ethnic
groups and has been identified in countries throughout
the world.
Diagnosis
Diagnosis is usually made by a paediatrician, clinical geneticist or a cardiologist
when a child presents with a development delay, typical features or with
a heart murmer or with elevated blood calcium. A specific blood test can
confirm the diagnosis.
Physical
features and symptoms
Each person with WS will have some but not all of the following signs and characteristics
...
Facial
features
These include a small upturned nose with a flattened bridge. Flat cheek bones
but full cheeks. Puffincess around the eyes. Long philtrum (upper lip length).
Full lips, open mouth, Small irregular teeth. Blue and green-eyed children
with Williams syndrome can have a prominent "starburst" or white
lacy pattern on their iris. Facial features become more apparent with age.
Heart
and blood vessel problems
Most common heart disorders are supravalvular aortic stenosis (narrowing),
and pulmonary stenosis. These conditions are usually mild, but can be more
serious requiring surgery. High blood pressure is an increasing risk with age.
Periodic monitoring of cardiac status is necessary.
Hypercalcemia
(elevated blood calcium levels)
Some babies have raised blood calcium levels leading to vomiting, colic, constipation
and sleeping problems, A low calcium diet stabilises the situation. The problem
usually resolves in early childhood, but lifelong abnormality in calcium or
Vitamin D metabolism may exist and should be monitored.
Growth
and Feeding
Low birth weight, poor weight gain. Difficult feeders, vomiting and failure
to thrive are symptoms. These problems have been linked to low muscle tone,
severe gag reflex, poor suck/swallow, tactile defensiveness etc. Feeding difficulties
tend to resolve as the children get older. Many adults become obese.
Irritability
(colic during infancy)
Many infants with Williams syndrome have an extended period of colic or irritability.
This typically lasts from 4 to 10 months of age, then resolves. It is sometimes
attributed to hypercalcemia. Abnormal sleep patterns with delayed acquisition
of sleeping through the night may be associated with the colic.
Dental
abnormalities
Slightly small, widely spaced teeth are common in children with Williams syndrome.
They also may have a variety of abnormalities of occlusion (bite), tooth shape
or appearance. Most of these dental changes are readily amenable to orthodontic
correction.
Kidney,
bladder and bowel
Bedwetting, cystitis. Frequency and urgency. Constipation; adults can develop
diverticulosis of the bladder and bowel.
Hernias
Inguinal (groin) and umbilical hernias are more common in Williams syndrome
than in the general population.
Hyperacusis
(sensitive hearing)
Children with Williams syndrome often have more sensitive hearing than other
children; Certain frequencies or noise levels can be painful an/or startling
to the individual. This condition often improves with age.
Body
structure
Young children with Williams syndrome often have low muscle tone and joint
laxity. As the children get older, joint stiffness (contractures) may develop.
Common features are long neck, sloping shoulders and distintive gait. In adults
stature is shorter than the family average. Often a protuding abdomen. Physical
therapy is very helpful in improving muscle tone, strength and joint range
of motion.
Psycohological
features
The level of intellectual handicap can vary greatly.
Developmental
delays
These can occur in walking and talking.
Hyperactivity
This can be accompanied by attention deficits.
Incoordination
Poor balance and fear of unstable surfaces.
Outgoing
personality
Very friendly and endearing. Unafraid of stangers. Loves to chat to adults
and cling to them.
Over
anxious personality
Disproportionately excited or upset by minor events.
Strengths
and weaknesses
These occur in intellectual ability. Good verbal ability after early delays.
Many have a good long term memory. Musical ability more commonly found in WS
than in the general population. Fine motor and visual spatial skills are weak
areas.
Obsessions
Most show strong enthusiasms for certain topics.
Who should care for individuals with Williams Syndrome?
Given the complex nature of many of the problems found in individuals with
Williams Syndrome, many health and educational professionals should be involved
in their care. Regular monitoring for potential medical problems is necessary
and should be done by a physician familiar with the broad array of problems
that can be seen in Williams syndrome.
Due to the intellectual "strengths and weaknesses," the expertise
of developmental psychologists, speech and language pathologists, physical
and occupational therapists, etc. who are familiar with Williams syndrome is
recommended.
Who
can help the families?
The New Zealand Williams Syndrome Association (NZWSA) offers help and support
for families with a child or adult diagnosed with Williams Syndrome. We can
put people in touch with other families similarly affected. We hold picnics
and get togethers, sometimes with a speaker. Every two years we have a 3 day
camp for the whole family.
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