First described by John Langdon Down,
Trisomy 21 described by Professor
Jérôme Lejeune & Turpin in 1959
In 1975, NIH suggested that possessive
use of eponym should be discontinued
95 % meiotic non-disjunction
4 % Robertsonian translocation
(from Chr 14 or 21 / 22)
1% due to mitotic non-disjunction with
In 75 % of cases extra chromosome is of
○ Short and stumpy fingers (Brachydactyly), Clinodactyly,
○ Simian crease (Siegert sign)
Distance between first and 2nd
Kennedy crease – Deep vertical crease in between
first and second toes
Acetabula are shallow- flattened lower edges
Ribs: Absence of one pair, 12th
Ulnar loops in most digits
Radial loops in fingers 4 and 5
Distal axial triradius or large ATD angle
Arch tibial or small loop distal in hallucal
Simian crease, single crease on finger 5
Moderate to severe MR
Epilepsy in 5 – 10 %
Alzheimer’s like syndrome
Cellular immune disorders
IgM levels decreased
Prone for viral UR infection
Popular Down Syndrome Stereotype
Fragile X syndrome
U/s – Double bubble
Echo - AV canal defects
X- Ray – Short femur or humerus
Echogenic small bowel
1. This test measures the alpha feto protein, produced by
the fetus, and
2. free beta hCG, produced by the placenta.
AFP / free beta screen - 80% detection rate
1. Thickened nuchal fold
2. Absent nasal bone
3. Short femur
4. Cardiac or GI anomalies
Uses ultrasound to measure Nuchal
Translucency in addition to the
Free Beta hCG and
PAPPA (pregnancy-associated plasma
NIH has confirmed that this first trimester test
is more accurate than second trimester
Nuchal translucency / free beta / PAPPA
screen: 91% detection rate
Screening – 1st
Maternal serum PAPP – A Increased
Maternal free β hCG Increased
Fetal nuchal translucenceny
> 4 mm (USG)
Screening – 2nd
E 3 Decrease
Inhibin A Increase
1. Only 11 ribs
2. 2 to 3 ossification centres for manubrium
3. Hypoplasia of skull and facial bones, middle
phalanx of little finger
4. Accessory epiphyses for 2nd
5. Coxa valga
6. Pelvis – ilia are broad and flaring, acetabular
and iliac angles are reduced
The sum of both the acetaular and
both iliac angles divided by two:
Normal = 81
In Down syndrome = < 60
Iliac Index in 2nd
– (80% accuracy)
Karyotype testing, if not already done
Hearing tests, which may be done at birth or by
3 months of age.
A complete blood count (CBC).
Check for signs of leukemia.
A blood test to check for thyroid problems
A complete heart evaluation
About 40% to 50% of babies with Down syndrome
have heart defects.
Birth to 1 mo.
50% to 70% risk for ear problems - otitis media with effusion
A special hearing test (behavioral audiogram) should be given
at 1 year of age. The Down Syndrome Medical Interest Group
(DSMIG) recommends another hearing evaluation at 6 months
Strabismus, cataracts, and nystagmus by 6 months of age.
at 6 months and 12 months (and annually after 1 year of age).
Growth and weight gain.
1 mo. To 1 year
X-rays to evaluate bones in the neck
Dislocation of the neck bones (atlantoaxial dislocation). between
ages 3 and 5 to look for signs of loose ligaments that may lead to
dislocation. These may be done only once.
Additional X-rays –
if child wants to participate in Special Olympics or
if symptoms such as neck soreness.
Early Childhood (1 to 5 yrs)
Extreme dryness, acne, or other problems may
develop during puberty that can get worse if they
are not recognized and treated.
You may be asked questions about your child's
sleeping habits, such as whether he or she
snores or is restless.
Middle and Late Childhood (5 to 13 yrs)
Eye problems. A teenager or adult should
have a thorough eye exam every year.
Adolescence (13 to 21 yrs)
Symptoms of sleep apnea.
Behavioral changes or signs of mental health problems.
Weight gain and signs of obesity.
Heart problems, such as mitral valve prolapse or aortic
Problems with the reproductive organs.
Women will have yearly breast exams.
Should be screened for thyroid problems every year.
Hearing should be tested every 1 to 2 years.
Should have a thorough eye exam every year
Walking and other motor development
Help your baby and young child strengthen
muscles through directed play.
Exercise program to help your child maintain
and increase muscle strength and physical
You can help your child learn to eat
independently by sitting down together
Use gradual steps to teach your child
how to eat, starting with allowing the
child to eat with his or her fingers and
offering thick liquids to drink.
Teach your child how to dress himself or
herself by taking extra time to explain
Simple measures, such as looking at
your baby while speaking or showing
and naming objects, can help your baby
learn to talk.
Grooming and hygiene.
Help your child learn the importance of
being clean and looking his or her best.
Establish a daily routine for bathing and
Gradually add new tasks to the routine,
such as putting on deodorant.
Often different types of therapy, such as
speech therapy, can help children with
Down syndrome learn necessary skills.
These therapies are used throughout life,
even during adulthood. The specifics
change as your child grows and develops.
Be aware of his or her vulnerabilities
and potential social problems. Although
your child can overcome
The typical life expectancy of people
with Down syndrome has nearly doubled
in recent decades, from 25 years in
1983 to 49 years in 1997
About 13% of people with Down
syndrome live longer than 68 years
System wise problems in Down’s
Alzheimer like disease after 25 yrs
CVS CHD 40% - AV cushion defects before 10 mo.
Cor pulmonale due to nasopharyngeal obstruction
due to tonsillitis / adenoiditis, hypotonia of
pharyngeal muscles, maldevelopment of upper
GIT Atresia of gut ( 8% newborns with Duodenal atresia)
Otological Impaired hearing (60-70% due to middle ear
Wax ( because auditory canal is narrow)
System wise problems in Down’s
Ocular Congenital cataracts 1% ( correct before 3 mo.)
Refractive Errors (70-80%)
Tear duct stenosis
Cataract after 25 yrs (12-86%)
Trace element deficiency
System wise problems in Down’s
Endocrine Congenital hypothyroidism 1%
Hypo or hyperthyroidism
Growth retardation – (selective def. of insulin like
growth factor 1 - result of hypothalamic dysfunction)
Girls fertile – boys sterile
Orthopedic Muscle hypotonia
Dislocation of patella and hip
Epiphysiolysis of hip
Atlantoaxial dislocation ( 10% radilolgically)