Transcript PRADER-WILLI SYNDROME

PRADER-WILLI SYNDROME
WHAT IS PRADER-WILLI
SYNDROME?
 Prader-Willi syndrome is a rare disorder present at birth that
results in a number of physical, mental and behavioral
problems. A key feature of Prader-Willi (PRAH-dur VIL-ee)
syndrome is a constant sense of hunger that usually begins
after the first year of life.
 People with Prader-Willi syndrome want to eat constantly
and usually have trouble controlling their weight. Many
complications of Prader-Willi syndrome are due to obesity.
Common Symptoms
 Infants
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Signs and symptoms of Prader-Willi syndrome generally occur in two stages.
Signs of the disorder that may be present in the first year of life include:
Poor muscle tone. A primary sign of Prader-Willi syndrome during infancy
is poor muscle tone (hypotonia). Babies may rest with their elbows and knees
loosely extended instead of fixed, and they may feel floppy or like "rag dolls"
when they're held.
Distinct facial features. Children with Prader-Willi syndrome may be born
with almond-shaped eyes, a narrowing of the head at the temples, a turneddown mouth and a thin upper lip.
Failure to thrive. During the first year of life, children with Prader-Willi
syndrome may have a poor sucking reflex due to decreased muscle tone.
Because poor sucking makes feeding difficult, they tend to gain weight slowly.
Lack of eye coordination (strabismus). The eyes of a child with PraderWilli syndrome may not move together. Therefore, they may cross or wander
to the side.
Generally poor responsiveness. A baby may seem unusually tired, respond
poorly to stimulation, wake with difficulty or have a weak cry.
Common Symptoms Cont’d
 Early childhood
From about ages 1 to 6, other signs of Prader-Willi appear. These problems will remain
present throughout life and require careful management or treatment. These signs may
include:
 Food craving and weight gain. The classic signs of the disorder are a constant craving
for food and a rapid gain in weight. Because a child with Prader-Willi syndrome is always
hungry, he or she eats frequently and consumes large portions. A child may develop
unusual food-seeking behaviors, such as hoarding food or eating things such as garbage or
frozen food.
 Underdeveloped sex organs. A condition called hypogonadism occurs when sex
organs — the testes in men and the ovaries in women — produce little or no sex
hormones. This results in underdeveloped sex organs, incomplete development at puberty
and in nearly all cases infertility.
Common Symptoms Cont’d
 Poor growth and physical development. Children with Prader-Willi syndrome have low
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muscle mass. They may have short hands and feet. When a person with the disorder reaches full
adult stature, he or she is usually shorter than other family members.
Learning disabilities. Mild to moderate mental retardation is a common feature of the
disorder. Essentially all people with Prader-Willi syndrome, even those without mental
retardation, have learning disabilities.
Delayed motor development. Toddlers with Prader-Willi syndrome often reach milestones
in physical movement later than other children. Sitting up by oneself may be delayed until 12
months and walking until 24 months.
Speech problems. Speech is often delayed until a child is 2 years of age. Poor articulation of
words may be an ongoing problem.
Behavioral problems. Children may at times be very stubborn or throw temper tantrums,
especially when denied food. They may also develop obsessive-compulsive disorder, which results
in unwanted, recurring thoughts or repetitive behaviors, or both. Other mental health disorders
may develop.
Sleep disorders. Some children with Prader-Willi syndrome may have sleep disorders,
including disruptions of the normal sleep cycle and sleep apnea, a condition in which breathing
pauses during sleep. Obesity may worsen sleep disorders.
Scoliosis. A number of children with Prader-Willi syndrome develop abnormal curvature of the
spine (scoliosis).
Common Symptoms Cont’d
 Other signs and symptoms of Prader-Willi syndrome may include:
 Nearsightedness (myopia)
 Light skin compared with other family members
 High pain tolerance
 Skin picking
 When to see a doctor
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A number of conditions can cause some of the early signs of Prader-Willi, such as a failure to
thrive, poor muscle tone and poor sucking. Therefore, it's important to get a prompt and
accurate diagnosis.
See the doctor if the infant:
Has difficulty feeding
Doesn't wake easily
Doesn't respond to touch
Has rag doll-like limbs
See a doctor if the older child shows any of the following signs:
Rapid weight gain
Constant hunger
Unusual food-seeking behaviors
Causes
 Although the exact genes responsible for Prader-Willi syndrome haven't
been identified, the problem is known to lie in a particular region of
chromosome 15.
 With the exceptions of genes related to sex characteristics, all genes
come in pairs, one copy inherited from the father (paternal gene) and one
copy inherited from the mother (maternal gene). For most types of
genes, if one copy is "active," or expressed, then the other copy is also
expressed.
 However, some types of genes act alone. In other words, it's normal with
certain genes for the paternal gene to be expressed and the maternal
gene to be "silent." Therefore, if there's an error with the paternal gene,
that piece of genetic information is essentially missing.
Causes Cont’d
 What happens in Prader-Willi syndrome
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Prader-Willi syndrome occurs because certain paternal genes that should
be expressed aren't for one of the following reasons:
Paternal genes on chromosome 15 are missing.
The person has inherited two copies of chromosome 15 from the mother
and no chromosome 15 from the father.
There's some error or defect in paternal genes on chromosome 15.
The genetic defect of Prader-Willi syndrome disrupts the normal
functions of a portion of the brain called the hypothalamus. Among its
many functions, the hypothalamus controls hunger and thirst and releases
hormones that prompt the release of other substances responsible for
growth and sexual development. A malfunctioning hypothalamus —
caused by the defect on chromosome 15 — interferes with each of these
processes, resulting in uncontrollable hunger, stunted growth, sexual
underdevelopment and other characteristics of Prader-Willi syndrome.
Risk Factors
 Defective or missing portions of paternal genes responsible
for Prader-Willi syndrome usually occur randomly. This
means that in most instances, Prader-Willi syndrome can't be
prevented. However, in a small number of cases, a genetic
mutation inherited from the father may cause Prader-Willi
syndrome.
 If you have a child with Prader-Willi syndrome and would
like to have another baby, consider seeking genetic
counseling. A genetic counselor may help determine the risk
of having another child with Prader-Willi syndrome.
COMPLICATIONS
 Obesity-related complications
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Many of the possible complications of Prader-Willi syndrome result from obesity. In
addition to having constant hunger, people with the disorder have low muscle mass,
which requires lower than average calorie needs. This combination of factors makes a
person prone to obesity and the medical problems related to obesity. These possible
complications include:
Type 2 diabetes. Type 2 diabetes is high blood sugar level due to the body's inability to
use insulin efficiently. Insulin plays a vital role in making blood sugar (glucose) — the
body's fuel — available to the cells. Obesity significantly increases the risk of diabetes.
Heart disease and stroke. People who are obese are more likely to have high blood
pressure, hardened arteries, high cholesterol and other factors that can lead to heart
disease and stroke.
Arthritis. Excess weight can cause the bone and cartilage of joints to wear down,
resulting in osteoarthritis.
Sleep apnea. This sleep disorder is characterized by pauses in breathing during sleep.
The disorder can cause daytime fatigue, high blood pressure and, rarely, sudden death.
People with Prader-Willi syndrome may have sleep apnea or other sleep disorders even
if they aren't obese, but obesity can worsen sleep problems.
COMPLICATIONS CONTINUED
 Complications of hypogonadism
Other complications arise from hypogonadism, a condition in which the sex
organs don't secrete sufficient amounts of the sex hormones testosterone
(males) and estrogen and progesterone (females). These may include:
 Sterility. Although there have been a few reports of women with Prader-Willi
syndrome becoming pregnant, most people with this disorder are unable to
have children (sterile).
 Osteoporosis. Osteoporosis is a condition characterized by weak and brittle
bones, which can break easily. People with Prader-Willi syndrome are at an
increased risk of developing osteoporosis because they have low levels of sex
hormones, which help maintain strong bones.
 Other complications
Eating large amounts of food quickly, called binge eating, can cause the child's
stomach to become abnormally distended (gastric dilatation). Binge eating can
also cause choking and any of the other complications associated with obesity.
TESTS AND DIAGNOSIS
 The presence of other signs, such as almond-shaped eyes or
narrowing of the head at the temples, may also prompt
testing. In older children, behavioral problems and weight
gain are often the key diagnostic signs of the disorder.
 A definitive diagnosis can almost always be made with a
laboratory test. Special genetic tests can identify
abnormalities in the child's chromosomes that are
characteristic of Prader-Willi syndrome.
Treatments and drugs
 A team of health professionals will likely work with you to manage the child's
condition. Most children with Prader-Willi syndrome will need the following
care and treatments:
 Good infant nutrition. Many infants with Prader-Willi syndrome have
difficulty feeding due to decreased muscle tone. The child's doctor may
recommend a high-calorie formula to help the baby gain weight and will
monitor the child's development as he or she begins to grow.
 Growth hormone treatment. Human growth hormone stimulates growth
and influences the body's conversion of food into energy (metabolism). Some
studies have suggested that growth hormone treatment in children with PraderWilli syndrome helps increase growth and decrease body fat, but the long-term
effects of growth hormone treatment aren't known. A doctor who treats
hormonal disorders (endocrinologist) can help determine whether the child
would benefit from growth hormone treatment.
 Sex hormone treatment. The endocrinologist may also suggest that the child
take hormone replacement therapy (testosterone for males or estrogen and
progesterone for females) to replenish low levels of sex hormones. Hormone
replacement therapy can help decrease the child's risk of developing thinning of
the bones (osteoporosis).
Treatments and Drugs
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 Healthy diet. A nutritionist may help you develop a healthy, reduced-
calorie diet to keep the child's weight under control while ensuring
proper nutrition.
 Overall development. The child will likely benefit from a range of
therapies, including physical therapy to improve movement skills and
strength; speech therapy to improve verbal skills and articulation;
occupational therapy to learn everyday skills; and developmental therapy
to learn age-appropriate behaviors, social skills and interpersonal skills.
In the United States, early intervention programs providing these types
of therapy are usually available for infants and toddlers through a state's
health department.
 Mental health care. A mental health professional, such as a
psychologist or a psychiatrist, may help address any psychological
problems the child may have, such as obsessive-compulsive disorder or a
mood disorder. Some children may need medication to control
behavioral problems.
Treatments and Drugs
Cont’d
 Transition to adult care
Most people with Prader-Willi syndrome will need
specialized care and supervision throughout their lives. Many
adults with the disorder live in residential care facilities that
enable them to eat healthy diets, live safely, work and enjoy
leisure activities.
 Organizations, such as the Prader-Willi Syndrome
Association, can help families find local resources and
services.
 Also, talk to a doctor for suggestions about making the
transition to adult medical care.
Lifestyle and home remedies
 Tips to help you take care of the child with Prader-Willi syndrome include the
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following:
Pick up the child carefully. Children with Prader-Willi syndrome have
poor muscle tone, which increases their risk of slipping between the hands
when you lift them under their armpits.
Take steps to help prevent binge eating. Adhering to a low-calorie diet is
essential to keep the child from becoming overweight. Try to avoid purchasing
high-calorie snacks. Store food out of the child's reach. Lock pantries,
refrigerators and cupboards. Use small dishes for serving meals.
Supplement the child's diet. If the child is on a restricted-calorie diet, ask
the doctor if supplemental vitamins or minerals are necessary to ensure
balanced nutrition.
Schedule appropriate screening tests. Be sure to talk to the doctor about
having the child screened for complications of Prader-Willi syndrome,
including diabetes, osteoporosis and an abnormally curved spine (scoliosis).
Ask the doctor about family support groups in the area. Organizations, such as
the Prader-Willi Syndrome Association, provide resources, support groups and
educational materials.
Source of Information
 http://www.mayoclinic.com/health/prader-willi-
syndrome/DS00922
 http://www.nichd.nih.gov/health/topics/Prader_Willi_Sy
ndrome.cfm