Jessica M Down Syndrome

Down syndrome is a developmental disorder caused by an extra chromosome 21. Having an extra chromosome means that each gene may be producing more protein product than normal. Producing way too much protein can have series consequences.

Down syndrome is caused by nondisjunction. If a pair of number 21 chromosomes fails to separate during the formation of an egg or sperm, this would be nondisjunction. When an egg units with a normal sperm to form an embryo, that embryo ends up with three copies of chromosomes 21 instead of the normal two. An extra chromosome is copied in every cell of the baby’s body. Nondisjunction occurs more to women over 35 years and older. A rare case of Down syndrome is caused by a Robertsonian translocation, which occurs when a long arm of a chromosome breaks off.

People with Down syndrome have very distinct facial features; flat face, a small broad nose. They would also have respiratory problems, Leukemia, and hearing loss. They would have mental retardation, develop more slowly. People with Down syndrome have trouble learning to talk, walk, and take care of themselves.

Daily Life:

Two types of test check for Down syndrome during a women’s pregnancy: Screening and diagnostic test. Screening tests identify a mother who is likely carrying a baby with Down syndrome. The most common screening tests are the Triple screen and Alpha-Fetoprotein Plus; they test the measure levels of certain substances in the blood. Ultrasounds allow the doctor to examine the fetus in the womb for physical signs of Down syndrome. You can take a blood sampling like, amniocentesis and percutaneous umbilical sampling. If Down syndrome is not found in the womb, they can recognize it when their born. They can tell if a baby has Down syndrome by their facial features.

Physical therapy and/or speech therapy can help people with Down syndrome develop more normally. Screening for common medical problems associated with the disorder, followed by corrective surgery can often improve quality of life. Environments increase their capacity to learn and lead a meaningful life.


Thanks to medical advances, heart problems and other physical issues have been effectively taken care of because of this success; individuals with Down syndrome live much longer than 15 years ago. They have been researching cognition. Cognition is a somewhat abstract concept: it involves processing of the information we perceive, understanding and remembering the environment around us. Scientists have made a mouse model of Down syndrome, in order to see how cognition and memory are affected by extra copies of 21st chromosome. They are hopeful that in 10 years, a drug will help people with Down syndrome think and remember normally.

Additional Facts:
Down syndrome is the only trisomy compatible with life. Only two trisomy’s have been observed in babies born alive (13 and 18), but babies born with these trisomes have only 5% of surviving a year. 90% of Trisomy 21 cases, the additional chromosomes come from the mother’s egg rather than the father’s egg. Down syndrome effects 1 out of every 800 to 1,000 babies. Down syndrome was originally described in 1866 by John Landon Down. French doctor, Jerome Lejeune, discovered Down syndrome.

Pedigree Chart:


Resources To understand Down syndrome click on the links below:
Author/ Corporation or Organization: The University of Utah,**
Author/Corporation or Organization: March of dimes
Author/Corporation or Organization: Stanford School of Medicine