Trisomy 21 is the most common chromosomal anomaly in humans, affecting about 5,000 babies born each year and more than 350,000 people in the United States. Also known as Down syndrome, trisomy 21 is a genetic condition caused by an extra chromosome. Most babies inherit 23 chromosomes from each parent, for a total of 46 chromosomes. Babies with Down syndrome however, end up with three chromosomes at position 21, instead of the usual pair. Other examples of trisomies occur at position 13 and 18. Trisomy 21 is the most common of the three, occurring in 1 out of every 691 births. The disorder was first identified in 1866 by John Langdon Down, a British physician, and later named after him. As your child with Down syndrome grows, he is at greater risk for certain medical problems and may develop: Problems in any of these areas can affect your child's development and behavior.
Down syndrome occurs because of the extra copy of chromosome 21, which can cause the body and brain to develop differently than a child without the syndrome. The risk of having a baby with Down syndrome increases as a woman ages — women older than 35 are often encouraged to have prenatal genetic testing done of their unborn babies — but, because younger women have more babies, they give birth to 80 percent of babies with Down syndrome.
Symptoms of Down syndrome may include:
Tests to confirm Down syndrome are often done before a baby is born through amniocentesis or chorionic villus sampling (CVS). For amniocentesis, a needle is inserted through the mother’s abdominal wall into the amniotic sac and a small sample of amniotic fluid is drawn out and tested in a laboratory. If your child was not prenatally diagnosed with Down syndrome, diagnosis usually begins at birth based on your child’s physical appearance. Doctors will ask you for a thorough family medical history, do a physical exam of your child, and analyze your child’s chromosomes. Once a diagnosis is made, additional testing may be ordered to help clinicians better understand how Down syndrome may affect your child and help spot any early complications from the disorder. Tests may include:
There is no cure for Down syndrome. Treatment is ordered when certain issues — such as heart problems, muscle weaknesses or spinal curvatures — occur and need to be treated. At Children’s Hospital of Philadelphia (CHOP), we practice collaborative, family-centered care. A team of expert clinicians — including world-class surgeons and physicians, pediatric nurses, physical and occupational therapists, psychologists and other specialists — will partner with you in the care of your child. Many children with Down syndrome are also diagnosed with a variety of secondary conditions that are present at birth and can be treated when your child is young. This is often true for conditions such as heart issues, hand and foot anomalies. In other cases, the complications from Down syndrome may only become evident — or problematic — as your child grows. This is often true for spinal deformities such as scoliosis and hip conditions that might require surgical correction. Every child’s condition is different, so treatment is determined on a case-by-case basis. Depending on your child’s needs, specialists from cardiology, orthopaedics, endocrinology and others will treat your child. Treatment may include therapy, surgery or additional support services for your child and family. A Care Binder can help you organize the most important information about your child's care in a central place.
Your child with Down syndrome should continue to be monitored by a physician into adulthood. Experts in the Trisomy 21 Program at CHOP are available to help you manage the care of your child with Down syndrome at all stages of growth. The Trisomy 21 Program is one of the few programs at Children's Hospital that treats patients beyond age 18 and into old age. If your child had surgery, she will need to follow up with her surgeon about one to two weeks after surgery, then again at three and six months post-surgery. After that, annual monitoring by trained clinicians is strongly encouraged to ensure any problems are spotted and treated as soon as possible. During follow-up visits, your child may need additional X-rays and other diagnostic testing done. The goal of continued monitoring is to help spot any irregularities in growth or development and to address health issues as they develop. Follow-up care and ongoing support and services are available at our Main Campus and throughout our CHOP Care Network. Our team is committed to partnering with parents and referring physicians to provide the most current, comprehensive and specialized care possible for your child. In addition, physicians may recommend your child see several different specialists because so many body systems can be involved in a diagnosis of Down syndrome. For example, your child may see:
In 1983, the life expectancy for people with Down syndrome was 25 years; however today, it is 60 years. Advances in cardiology have significantly contributed to this rapid increase. As science and technology continue to improve and the intricacies of Down syndrome are explored and discovered, it is expected that the life expectancy for people with Down syndrome will continue to increase too. Today, children with Down syndrome are included in regular academic classrooms in schools across the country. In some instances they are integrated into specific courses, while in other situations students are fully included in the regular classroom for all subjects. The degree of mainstreaming is based in the abilities of the child. Many people with Down syndrome have gone to college, live independently and hold jobs. These individuals are hard workers and dedicated employees. A stimulating home environment, positive support from family and friends, quality educational programs and good healthcare enable people with Down syndrome to develop their full potential and lead fulfilling lives. Be creative, persistent and set high expectations. Despite the advances, children with Down syndrome continue to have a higher risk of developing certain health conditions, such as heart disease, gastrointestinal abnormalities and dementia. Early diagnosis and treatment of these associated conditions leads to better outcomes. With regular medical care and a solid support system, children with Down syndrome can lead long, full and happy lives. URL of this page: https://medlineplus.gov/genetics/condition/down-syndrome/
Down syndrome is a chromosomal condition that is associated with intellectual disability, a characteristic facial appearance, and weak muscle tone (hypotonia) in infancy. All affected individuals experience cognitive delays, but the intellectual disability is usually mild to moderate. People with Down syndrome often have a characteristic facial appearance that includes a flattened appearance to the face, outside corners of the eyes that point upward (upslanting palpebral fissures  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 Delayed development and behavioral problems are often reported in children with Down syndrome. Affected individuals can have growth problems and their speech and language develop later and more slowly than in children without Down syndrome. Additionally, speech may be difficult to understand in individuals with Down syndrome. Behavioral issues can include attention problems, obsessive/compulsive behavior, and stubbornness or tantrums. A small percentage of people with Down syndrome are also diagnosed with developmental conditions called autism spectrum disorders, which affect communication and social interaction. People with Down syndrome often experience a gradual decline in thinking ability (cognition) as they age, usually starting around age 50. Down syndrome is also associated with an increased risk of developing Alzheimer disease, a brain disorder that results in a gradual loss of memory, judgment, and ability to function. Approximately half of adults with Down syndrome develop Alzheimer disease. Although Alzheimer disease is usually a disorder that occurs in older adults, people with Down syndrome commonly develop this condition earlier, in their fifties or sixties. Down syndrome occurs in about 1 in 700 newborns. About 5,300 babies with Down syndrome are born in the United States each year, and approximately 200,000 people in this country have the condition. Although women of any age can have a child with Down syndrome, the chance of having a child with this condition increases as a woman gets older. Most cases of Down syndrome result from trisomy 21 Less commonly, Down syndrome occurs when part of chromosome 21 becomes attached (translocated A very small percentage of people with Down syndrome have an extra copy of chromosome 21 in only some of the body's cells. In these people, the condition is called mosaic Researchers believe that having extra copies of genes on chromosome 21 disrupts the course of normal development, causing the characteristic features of Down syndrome and the increased risk of health problems associated with this condition. Most cases of Down syndrome are not inherited. When the condition is caused by trisomy 21, the chromosomal abnormality occurs as a random event during the formation of reproductive cells in a parent. The abnormality usually occurs in egg cells, but it occasionally occurs in sperm cells. An error in cell division called nondisjunction results in a reproductive cell with an abnormal number of chromosomes. For example, an egg or sperm cell may gain an extra copy of chromosome 21. If one of these atypical reproductive cells contributes to the genetic makeup of a child, the child will have an extra chromosome 21 People with translocation Down syndrome can inherit the condition from an unaffected parent. The parent carries a rearrangement of genetic material between chromosome 21 and another chromosome. This rearrangement is called a balanced translocation Like trisomy 21, mosaic Down syndrome is not inherited. It occurs as a random event during cell division early in fetal development. As a result, some of the body's cells have the usual two copies of chromosome 21, and other cells have three copies of this chromosome. Learn how to cite this page |
What is the most common source of the extra chromosome 21 in an individual with Down syndrome
zusammenhängende Posts
Urheberrechte © © 2024 frojeostern Inc.
