Down Syndrome
#57
Down syndrome is a genetic condition that occurs when an extra copy of chromosome 21 is created. The normal amount of chromosomes in a human cell is 46, but with Down syndrome, there are 47 chromosomes in a cell. This condition affects a person both physically and mentally.
Symptoms
People with Down syndrome usually have distinct physical features. Some features include a flat face, a flat nose bridge, almond-shaped eyes that slant upward, hands with a single crease in the palm, small stature, poor muscle tone, loose joints, and a short neck.
People with Down syndrome may also have developmental delays (e.g., talking, walking, sitting), intellectual disabilities, or behavioral symptoms such as stubbornness, tantrums, and difficulty paying attention.
Around 50-65% of babies born with Down syndrome are also born with a congenital heart defect, which may require surgery. Children with Down syndrome are also at a higher risk for conditions such as ear infections, hearing loss, eye diseases, obstructive sleep apnea, and Alzheimer’s disease.
Types
Trisomy 21:
most common type (95%)
occurs when there are 3 separate copies of chromosome 21
Translocation:
3% of people who have Down syndrome
partial/full copy of chromosome 21 attached (translocated) to another chromosome
Mosaic:
2% of people who have Down syndrome
only some cells contain an extra copy of chromosome 21, while others have the normal amount of chromosomes
Treatment
There is no cure for Down syndrome, but there are various treatments available depending on the symptoms (therapy, special education, etc).
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