Down syndrome is one of the most frequently occurring
birth defects in the world. It is a chromosomal abnormality
which results in 47 chromosomes, instead of 46, with an extra
chromosome being 21. Because the majority of Down syndrome
cases affect the twenty-first chromosome, it is commonly called
Down syndrome is usually caused by a cell division error,
which is known as non-disjunction. This occurs when an embryo
develops with three number 21 chromosomes instead of two.
excess genetic material alters the course of development and
causes the characteristics of this syndrome. The cause of this
faulty cell division is still unknown, although there seems to
be some relatedness to maternal age. There are two other types
of Down syndrome, mosaicism and translocation, but these do not
affect individuals as frequently as non-disjunction.
Mosaicism is a mixture of two cell types, leaving the
individual with some normal chromosomes of 46, and some
affected ones with 47. Translocation occurs when part of the
twenty-first chromosome breaks off and attaches to another
cell. The total number of chromosomes is 46, however the
excess material from the twenty-first chromosome results in the
affects of the syndrome.
With translocation, most cases occur
sporadically, with no bearing on maternal age. These two types
of this syndrome are very rare, being responsible for only 6 or
7 percent of all cases.
Children with Down syndrome are at high risk for health
problems. These include congenital heart defects, respiratory
problems, increased suseptibility to infections, and/or
obstructed digestive tracts. Leukemia has a greater frequency
of appearance among children with Down syndrome, and adults are
at an increased risk for Alzheimer’s disease. Advances in
medicine have helped these individuals with their health
problems, and generally people with Down syndrome have a life
expectancy of 55 years.
The mental development of people with Down syndrome is
challenged through some degree of mental retardation. Typically,
the level of mental retardation falls into the mild to moderate
range, but some cause can range severely. However, people with
Down syndrome possess a multitude of individual strengths and
talents. For this reason, a child should have as many services
accessible to them throughout their entire development. Early
intervention services, stimulating home environments, and good
medical care are of the utmost importance for a child with Down
syndrome, and will help a child develop to his/her full potential.
Individuals with Down syndrome are becoming increasingly
involved with society and community organizations, and more
people will interact with these individuals.
is an increasing need for education and acceptance of people
with this syndrome.
Unknown author. “Down Syndrome. Public Health Education
Information Sheet.” Online
Unknown author. “Down Syndrome.” Online
Unknown author. “Down Syndrome:For New Parents.” Online