Down Syndrome is a birth defect caused by a genetic disorder that affects 350,000 people in the United States.
It is caused by abnormalities in the genes and is not inherited, meaning that parents do not pass this onto their children. Genetics is the study of heredity or how certain traits are passed from parents to their children. Genes are the basic unit of heredity. Cells are the building blocks of your body and each one of us has more than 100 trillion cells. Our genes are located in chromosomes.
Each cell in your body contains 46 chromosomes or 23 pairs. In a person with Down syndrome, there are 47 chromosomes. In 1956, a French researcher named Jerome Lejeune used a new powerful microscope to view human strands of DNA. DNA is what holds an individual person’s genes.
He studied these DNA strands and determined that there is an extra strand in chromosome 21, which is now called “Trisomy 21” tri meaning three and somy for the word chromosome – meaning three chromosomes. No one knows exactly what causes Down syndrome aside from it being genetic. Many years ago, this condition was known as “mongolism” or people that had it were called “mongolian idiots”. But in later years, Asian people as well as parents of these children protested these terms and in the 1960’s the condition became known as Down syndrome in honor of the English doctor John Langdon Down. Who, in 1866, studied people with mental retardation and noted distinct physical features in them.
Some of the physical features associated with Down syndrome are low muscle tone, many newborns appear as floppy and not toned, they have flat facial features especially a small nose with a flattened nasal bridge. Their eyes are slightly slanted with small skin folds at the inner corner. The have a short neck, small abnormal shaped ears, and an enlarged tongue that often tends to protrude making speech difficult to understand. Many people with Down syndrome suffer from a variety of health problems. The most common and significant symptom is mental retardation, which ranges from mild to moderate.
People with Down syndrome suffer from congenital heart defects, which affect approximately 40-50% of these people. Their poor muscle tone makes much physical activity difficult. There are many hormonal problems, mainly thyroid disease. People with Down syndrome suffer from circulatory problems, respiratory ailments, and digestive problems.
Nearly 70% of infants have some type of problem with their eyes. The most common eye problem is eye muscle imbalance, known as strabismus which causes the eyes to cross. About 50% afflicted with Down syndrome will suffer from hearing loss. Many of these problems can be serious or even life threatening but fortunately, most of them can be treated if they are detected early. Due to the nature of the disease and the many health issues involved, the life expectancy for a person with Down syndrome is only 50-65 years. Babies are born with poor muscle tone causing weak muscles and making it harder for them to develop motor skills such as using their arms and legs.
It is harder for them to grasp objects, crawl, and walk. Children with Down syndrome have difficulty with their cognitive (thinking) abilities, problem solving, memory retention, social, language, and motor skills. This is one reason why people with Down syndrome become frustrated very easily. Although people with disabilities are becoming more acceptable in society, we still have a long way to go. Congress has passed many laws to help the disabled such as the Rehabilitation Act of 1973, Education for All Handicapped Children Act of 1975, and the most well known, Americans with Disabilities Act of 1991.
People with Down syndrome just want to be like every one else. Many of these people live “normal” lives. They go to school and learn, they are taught skills and learn to be independent, they work and even get married. There is genetic research and studies in biochemistry to find a way to prevent Down syndrome.
The best known research study is the Human Genome Project which is identifying the genes in the human body. This project is being done by scientists all over the world. They are trying .