Down Syndrome
Overview
Down syndrome occurs when an individual has a full or partial extra copy of chromosome 21.
This additional genetic material alters the course of development and causes the characteristics associated with Down syndrome. A few of the common physical traits of Down syndrome are low muscle tone, small stature, an upward slant to the eyes, and a single deep crease across the center of the palm – although each person with Down syndrome is a unique individual and may possess these characteristics to different degrees, or not at all.
Diagnosis Criteria
There is an extensive menu of prenatal screening tests now available for pregnant women. Most screening tests involve a blood test and an ultrasound (sonogram). The blood tests (or serum screening tests) measure quantities of various substances in the blood of the mother.
The diagnostic procedures available for prenatal diagnosis of Down syndrome are chorionic villus sampling (CVS) and amniocentesis. These procedures, which carry up to a 1% risk of causing a spontaneous termination (miscarriage), are nearly 100% accurate in diagnosing Down syndrome. Amniocentesis is usually performed in the second trimester between 15 and 20 weeks of gestation, CVS in the first trimester between 9 and 14 weeks.
Regardless of the type of Down syndrome a person may have, all people with Down syndrome have an extra, critical portion of chromosome 21 present in all or some of their cells. This additional genetic material alters the course of development and causes the characteristics associated with Down syndrome.
The cause of the extra full or partial chromosome is still unknown. Maternal age is the only factor that has been linked to an increased chance of having a baby with Down syndrome. However, due to higher birth rates in younger women, 80% of children with Down syndrome are born to women under 35 years of age.
There is no definitive scientific research that indicates that Down syndrome is caused by environmental factors or the parents’ activities before or during pregnancy.
The additional partial or full copy of the 21st chromosome which causes Down syndrome can originate from either the father or the mother. Approximately 5% of the cases have been traced to the father.
Research Based Treatments
Good Books
Early Communication Skills for Children with Down Syndrome: A Guide for Parents and Professionals (Topics in Down Syndrome) 3rd Edition | Libby Kumin
Find it on Amazon
Supporting Positive Behavior in Children and Teens with Down Syndrome: The Respond but Don't React Method | David Stein
Find it on Amazon
Hannah's Down Syndrome Superpowers (One Three Nine Inspired) | Lori Leigh Yarborough and Roksana Oslizlo
Find it on Amazon
National Association for Down Syndrome
The National Association for Down Syndrome supports all persons with Down syndrome in achieving their full potential.
In fulfilling our mission, we will:
Provide families with Down syndrome members with information and resources to enable them to access and evaluate appropriate services.
Educate the public about Down syndrome.
Address social policy issues and challenges facing the Down syndrome community.
Facilitate and encourage active participation by self-advocates and families in the delivery of education, vocational, residential and other services for persons with Down syndrome.
The National Down Syndrome Congress (NDSC) is a not-for-profit organization dedicated to an improved world for individuals with Down syndrome. Founded in 1973, we are the leading national resource of support and information about Down syndrome, from the moment of a prenatal diagnosis through adulthood.