What is Down syndrome?
Down syndrome is a chromosomal condition that is associated with intellectual disability, a characteristic facial appearance, and poor muscle tone (hypotonia) in infancy. The degree of intellectual disability varies, but it is usually mild to moderate. People with Down syndrome may be born with a variety of birth defects. About half of all affected children have a heart defect. Digestive abnormalities, such as a blockage of the intestine, are less common. Individuals with Down syndrome have an increased risk of developing several medical conditions. These include gastroesophageal reflux, which is a backflow of acidic stomach contents into the esophagus, and celiac disease, which is an intolerance of a wheat protein called gluten. About 15 percent of people with Down syndrome have an underactive thyroid gland (hypothyroidism). The thyroid gland is a butterfly-shaped organ in the lower neck that produces hormones. Individuals with Down syndrome also have an increased risk of hearing and
Down syndrome is a chromosomal disorder that includes a combination of birth defects. Affected individuals have some degree of mental retardation, characteristic facial features and, often, heart defects and other health problems. The severity of these problems varies greatly among affected individuals. How common is Down syndrome? Down syndrome is one of the most common genetic birth defects, affecting about 1 in 800 babies (1). According to the National Down Syndrome Society, there are approximately 350,000 individuals with Down syndrome in the United States (2). What causes Down syndrome? Down syndrome is caused by extra genetic material from chromosome 21. Chromosomes are the structures in cells that contain the genes. Each person normally has 23 pairs of chromosomes, or 46 in all. An individual inherits one chromosome per pair from the mother’s egg and one from the father’s sperm. When an egg and sperm cell join together, they normally form a fertilized egg with 46 chromosomes. So
Down syndrome is a chromosomal disorder caused by an error in cell division that results in an extra 21st chromosome. The condition leads to impairments in both cognitive ability and physical growth that range from mild to moderate developmental disabilities. Through a series of screenings and tests, Down syndrome can be detected before and after a baby is born. The only factor known to affect the probability of having a baby with Down syndrome is maternal age. That is, less than one in 1,000 pregnancies for mothers less than 30 years of age results in a baby with Down syndrome. For mothers who are 44 years of age, about 1 in 35 pregnancies results in a baby with Down syndrome. Because younger women generally have more children, about 75 – 80% of children with Down syndrome are born to younger women.
People with Down syndrome are first and foremost human beings who have recognizable physical characteristics and limited intellectual endowments which are due to the presence of an extra chromosome 21. The estimated incidence of Down syndrome is between 1 in 1,000 to 1 in 1,100 live births. Each year approximately 3,000 to 5,000 children are born with this chromosome disorder. It is believed there are about 250,000 families in the United States who are affected by Down syndrome.
Down syndrome (DS), also called Trisomy 21, is a condition in which extra genetic material causes delays in the way a child develops, both mentally and physically. It affects about 1 in every 800 babies. The physical features and medical problems associated with Down syndrome can vary widely from child to child. While some kids with DS need a lot of medical attention, others lead healthy lives. Though Down syndrome can’t be prevented, it can be detected before a child is born. The health problems that can go along with DS can be treated, and there are many resources within communities to help kids and their families who are living with the condition.
