What Is Down Syndrome?

Reviewed on 9/3/2020

What is Down syndrome?

Down syndrome is caused by the presence of an extra chromosome.
Down syndrome is caused by the presence of an extra chromosome.

Down syndrome is a type of genetic disorder in which a person has an extra chromosome (rod-like structures that contain genes) inside the cells. The syndrome is named after the English physician John Langdon Down who provided the first accurate description of this condition. Down syndrome is the most common chromosomal condition affecting approximately one in every 700 babies born in the United States. Around 6,000 babies are born with Down syndrome each year in the United States.

Each cell in the human body has a structure called a nucleus in which the genes are present. The genes are arranged in certain rod-like structures called chromosomes. They can be described as small “packages” of genes in the body. They control the inherited traits such as how a baby develops inside the womb and how the baby’s body functions as it grows in the womb and after birth. Normally, each cell contains 46 chromosomes arranged in 23 pairs. In the case of a baby with Down syndrome, there is an extra copy of one of these chromosomes, that is, chromosome 21. This condition where instead of two chromosomes three are present is called trisomy, or trisomy 21,  in the case of Down syndrome. 

The presence of an extra copy of chromosome 21 changes how the baby’s body and brain develop in Down syndrome. This may cause some physical and mental abnormalities such as low intelligence quotient (IQ), poor muscle tone, short stature, an upward slant to the eyes and a single deep crease across the center of the palm. Each person with Down syndrome, however, is a unique individual and may have these characteristics to a different extent or not at all.

What are the symptoms of Down syndrome?

Down syndrome poses mental and physical challenges for the affected individual. Although individuals with this condition may look or act similarly, each has different abilities. A person with Down syndrome generally has an intelligence quotient (IQ), which is a measure of intelligence, in the mild-to-moderate low range. Children with this condition are slower to speak than other children.

Some of the common physical signs of Down syndrome include

  • Flattened face, especially the bridge of the nose
  • Almond-shaped eyes slanting upward
  • Short neck
  • Small ears
  • Protruding tongue where the tongue  tends to stick out of the mouth
  • Small hands and feet
  • Single palmar crease, which isa line across the palm
  • Broad and short hands with small pinky fingers that may curve toward the thumb
  • Low muscle tone or loose joints
  • Shorter stature for their age
  • Tiny white spots on the iris, the colored part of the eye

Is Down syndrome curable?

Down syndrome is not curable. It is a lifelong condition. Supportive therapy early in life can often help babies and children with Down syndrome to improve their physical and mental abilities. Early screening of babies with Down syndrome can also help in managing associated conditions such as heart defects and hearing problems. Supportive therapy helps children with Down syndrome develop to their full potential. The therapy includes speech, occupational and physical therapy besides extra help and support in school. 

From WebMD Logo

Health Solutions From Our Sponsors

References
Medscape Medical Reference

National Down Syndrome Society


CDC


Health Solutions From Our Sponsors