What is Trisomy 21?
Trisomy 21, also known as Down Syndrome, is a genetic disorder that occurs when a person has 47 chromosomes instead of the 46 normal chromosomes. In a normal human cell there are 23 pairs of chromosomes that contain genetic information. In the case of Down Syndrome, chromosome 21 usually has a third copy. This third copy of chromosome 21 is whats responsible of most of the malformation in a human being. The malformation or birth defects range from body and brain development.
It has been suggested that advanced maternal age can pose a greater risk for bearing a child with Trisomy 21. For a woman that is under the age of 35 the chances of having a child with Trisomy 21 are 1 in 1ooo. On the other hand, the chances for women older than 35 changes dramatically to 1 in 200. This means that women that 35 years of age or older bear 15% of all the babies born and have 50% of babies that are born with Down Syndrome.
History of Trisomy 21
Trisomy 21 is known today as Down Syndrome in the honor of John Langdon Down. Most would agree that in 1866 Down was one of the first physicians to observe the similar traits among his mentally retarded patients. In the 1930’s physicians started to suggest that Down Syndrome was due to a chromosomal abnormality. It wasn’t until 1959 that researchers confirmed that down syndrome was due to the presence of three copies of chromosome 21.
Symptoms
The symptoms of Trisomy 21 vary from person to person and can be present at different degrees.
Physical Development:
- Broad & Flat Face
- Thick tongue
- Small nose
- Oval shapes eyes
- Excess skin at nape of neck
- Single crease in palm of hand
- White spots on colored part of eye (Brushfield Spots)
- Small ears
- Decreased muscle tone
- Extremely flexible joints
Mental and Social Development:
- Short attention span
- Slow learning
- Impulsive behavior
- Poor Judgment
Medical Conditions:
- Congenital Heart Disease ( atrial and/or ventricular septal defect)
- Gastrointestinal blockage
- Hearing loss
- Eye disorders
- Leukemia
- Thyroid Disorders