Down syndrome Stats:
Down syndrome occurs in every 600-800 births.
It is caused by an extra copy of the 21st chromosome.
There are 3 types of Down syndrome:
Nondisjunction makes up 94% of all cases. This means that every cell has the extra 21st chromosome.
Translocation makes up 3-4% of all cases. This is an inherited form of Down syndrome.
Mosaic makes up 2% of all cases. This means that not every cell has the extra chromosome.
The diagnosis of Down syndrome is made by a chromosome analysis test called a Karyotype.
There is a slight reccurence risk for future pregnancies.
Features of Down Syndrome:
Individuals with Down syndrome may have a few or all of the following characteristics:
Flattened nose / flat facial profile (90%)
Upward slanting, almond-shaped eyes (80%)
Low muscle tone / hypotonia (80%)
Increased flexibility (80%)
Excess skin on back of neck (80%)
Small, simple ears (60%)
Poorly developed 5th finger (60%)
Brushfield spots on the iris of the eye
Skin folds of upper eyelid covering inner corner of the eye / epicanthal folds
Short, broad hands with short fingers
5th finger curves inward
Single crease on the palm of the hand
Wide gap between 1st & 2nd toes / sandal gap
Fusion / syndactyly of 2nd and 3rd toes
Medical Complications Associated with Down syndrome
Early-Onset Alzheimer Disease (11% by age 50; 77% by age 70)
Dry, Hardened, Flaky Skin (75%)
One or More Abnormalities Present at Birth (50%)
Heart Defect Possibly Requiring Open Heart Surgery (40-60%)
Thyroid Disorders (up to 50%)
Obstructive Sleep Apnea / Pauses in Breathing During Sleep (33%)
Atlantoaxial and/or Atlantooccipital Instability (10-30%)
Blockage in Stomach or Intestines Possibly Requiring Surgery (12%)
Autistic Disorder (5- 11%)
Seizures / Epilepsy (10%)
Increased Risk of Childhood Leukemia (2%)
Increased Susceptibility to Infection
Increased Susceptibility to Dental Problems
Increased Risk of Autoimmune Disease
Problems with Muscles & Skeletal System
Tendency for Obesity / Weight Gain
Males are Unable to Reproduce
Increased Risk of Testicular Cancer in Males
Intellectual Disability & Developmental Delay for Individuals with Down syndrome
Variable Range of Mental Retardation from Mild to Moderate
Mean (Average) IQ of 42
Range of IQ from 8 to 67
Developmental Delay in Achieving Milestones
Need for Physical Therapy
Need for Occupational Therapy
Need for Speech Therapy
Need for Early Intervention & Case Management
Long-Term Prognosis for Individuals with Down syndrome
Participate in Community Sports, Activities, & Leagues
Participate in Special Olympics & Therapeutic Recreation
Inclusion in Regular Classes
Special Education Classes
Complete High School
Attend College or Post-Secondary Education
Employed in Workshop Setting
Live in Group Home
Have Intimate Relationships
Life Expectancy (age range of 50s-60s)
More Like Other Children Than Different
Check back later for fun facts about Down syndrome!