DOWN SYNDROME
definition, history, types, signs, diagnosis, and treatment
WHAT IS DOWN SYNDROME?
It is a genetic condition caused
by the presence of all or part of a
third copy of chromosome 21. It
is typically associated with
physical growth delays,
characteristic facial features, and
mild to moderate intellectual
disability.
THE DISCOVERY OF DOWN SYNDROME
Neurodevelopmental
syndrome named for John
Langdon Haydon Down who
first described the physical
and behavioral
characteristics in 1862
THE DISCOVERY OF DOWN SYNDROME
In 1958, the French physician
Jérôme Lejeune identified Down
syndrome as a chromosomal
condition. Instead of the usual 46
chromosomes present in each
cell, Lejeune observed 47 in the
cells of individuals with Down
syndrome.
TYPES OF DOWN SYNDROME
Is caused by an error in
cell division called
nondisjunction.
TRISOMY 21
This leaves a sperm or
egg cell with an extra copy
of chromosome 21 before
or at conception.
Some cells in the body are
normal while others have
Trisomy 21.
MOSAIC DOWN
SYNDROME
Occurs when part of chromosome
21 breaks off during cell division
and attaches to another
chromosome, usually
chromosome 14.
ROBERTSONIAN
TRANSLOCATION
A person with a translocation does
not have any special physical
features, but they are more likely to
have a child with an extra 21st
chromosome.
TRISOMY 21
Is caused by a failure
of the 21st
chromosome to
separate during egg
or sperm development
(nondisjunction).
Trisomy 21 is also
known by the
karyotype 47,XX,+21
for females and
47,XY,+21 for males
A sperm or egg cell is produced
with an extra copy of
chromosome 21; this cell thus
has 24 chromosomes. When
combined with a normal cell
from the other parent, the baby
has 47 chromosomes, with
three copies of chromosome
21.
Typical cell division- 46
chromosomes
Nondisjunction cell
division-47
chromosomes
SIGNS OF
DOWN
SYNDROME
Those with Down syndrome
nearly always have physical and
intellectual disabilities.As adults,
their mental abilities are typically
similar to those of an 8- or 9year-old.They also typically have
poor immune function and
generally reach developmental
milestones at a later age.They
have an increased risk of a
number of other health problems,
including congenital heart defect,
epilepsy, leukemia, thyroid
diseases, and mental disorders.
PHYSICAL CHARACTERISTICS
SMALL CHIN
LARGE TONGUE
ABNORMAL FINGERTIP
PATTERNS
POOR MUSCLE
TONE
SHORT NECK
SHORT FINGERS
FLAT NASAL
BRIDGE
FLAT AND WIDE
FACE
SHORT STATURE
SINGLE PALM
CREASE
EXTRA SPACES
BETWEEN TOES
OBESITY
Development in Down Syndrome
-Social and self help skills usually on track early and often remain strengths
-Motor skills (sitting, walking, running) delayed due to low muscle tone, joints
-Language skills often start on time, but usually slow in second year and
affect talking more than understanding
Learning Strengths:
Learning Difficulties:
-Social Development
-Learning with Visual Supports
-Word Reading
-Motor Development
-Grammar and Language
-Number skills
-Verbal Short-term memory
DIAGNOSIS OF DOWN SYNDROME
SCREENING TESTS
Women with a higher chance of having a child with Down
NUCHAL
TRANSLUCENCY
TESTING
TRIPLE OR
QUADRUPLE SCREEN
syndrome may receive screening and diagnostic tests.
INTEGRATED SCREEN
Screening tests can estimate the probability of Down syndrome
being present. Some diagnostic tests can definitively tell
whether the fetus has the condition.
CELL FREE DNA
GENETIC ULTRASOUND
DIAGNOSIS OF DOWN SYNDROME
DIAGNOSTIC TESTS
Diagnostic tests are more accurate in detecting
Down syndrome and other problems. They are
usually performed inside the uterus, and they
increase the risk of miscarriage, fetal injury, or
preterm labor.
CHORIONIC VILLUS
SAMPLING
AMNIOCENTESIS
PERCUNTANEOUS
UMBILICAL BLOOD
SAMPLING
Down Syndrome cannot be cured. However,
early treatment can help many people with Down
Syndrome to live productive lives well into
adulthood.
TREATMENT
There is no specific treatment for Down
syndrome.
Children with Down Syndrome can often benefit
from speech therapy, occupational therapy, and
exercises to help improve their motor skills. They
might also be helped by special education and
attention at school.
Some of the medical problems common in
people with Down Syndrome, like cataracts,
hearing problems, thyroid problems, and seizure
disorders, can be also treated or corrected.
Sources:
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www.mychildwithoutlimits.org
www.medicalnewstoday.com
en.wikipedia.org
www.betterhealth.vic.gov.au
2017.HQ_.CouncilMeeting.DownSyndromePresentation.UCD
_.9.19
www.down-syndrome.org