What is Down syndrome?
Down syndrome describes a set of cognitive and physical symptoms that result from an extra or partial copy of chromosome copy 21.
Chromosomes carrying genes that regulate the body develop in certain ways and perform certain functions. Most cells of the human body contain 23 pairs of chromosomes A set of chromosomes from each mother-child pair for a total of 46 chromosomes. People with Down syndrome have a full or partial copy of chromosome 21, for a total of 47 chromosomes. (The syndrome is sometimes called 47, XX, + 21 or 47, XY, + 21 to indicate chromosome adding 21.)
Extra chromosomes disrupt the normal development process and lead to physical characteristics , intellectual disabilities and development associated with the syndrome.
The degree of mental retardation in people with Down syndrome varies but is mild to moderate. Usually, children with Down syndrome reach their main developmental milestones later than others. People with the syndrome are also more likely to be born with heart abnormalities and they are at risk for hearing and vision problems, Al zheimer disease and other conditions. However, with the support and appropriate treatment, many people with Down syndrome have a happy, productive life. In recent decades, the life expectancy of people with Down syndrome has increased significantly, from 25 years (1983) to 60 years (now).
Down syndrome is named after John Langdon Down, the first doctor to describe this syndrome systematically.
What are the common symptoms of Down syndrome?
The symptoms of Down syndrome vary from person to person and people with Down syndrome may have different problems at different times in their lives.
Common physical signs of Down syndrome include:
– Decreased muscle tone or poor strength
– Short neck, with excess skin behind the neck
– Mirror surface
– Small head
– Slanted eyes facing up, there are often skin folds flowing out from the upper eyelid and hiding the inner corner of the eye
– White spots on the colored part of the eye (called Brushfield spots)
– Wide, short hands with short fingers
– A single, deep wrinkle, on the palm of the hand
– A deep groove between the first and second toes
In addition, the physical development in children with Down syndrome is usually slower than the development of children without Down syndrome. For example, due to poor muscle tone, a child with Down syndrome may slowly learn to turn, sit, stand and walk. Despite this delay, children with Down syndrome can learn to participate in physical activities like other children. It is possible to take children with Down syndrome longer than other children to reach developmental milestones, but eventually they will meet many of these milestones.
Symptoms of intelligence and development
Cognitive impairment, thinking and learning problems, is common in people with Down syndrome and usually ranges from mild to moderate. Only rarely Down syndrome is associated with severe cognitive impairment.
Other common cognitive and behavioral issues may include :
– Short attention span
– Bad judgment
– Impulsive behavior
– Study slowly
– Language and language development is delayed
Most children with Down syndrome develop the communication skills they need, although it may take more time to do so than other children. Early, ongoing verbal and language interventions to encourage expressive language and improve speech are particularly helpful.
Parents and families of children with Down syndrome can connect with other families and people with Down syndrome from around the world to learn more and share information. DS-Connect® is led by NICHD as a safe and confidential registry to help families and researchers identify similarities and differences in symptoms and physical development and development. development of people with Down syndrome and guide future research. Learn more about DS-Connect®: The Registry of Down Syndrome.
Relevant conditions and disorders
People with Down syndrome are at risk for a range of other health conditions, including autism spectrum disorders, hormone and gland problems, hearing loss, hearing problems and abnormalities. heart.
What causes Down syndrome?
Down syndrome is caused by a random error in cell division resulting in the presence of an extra copy of chromosome 21.
This type of error is called non-destructive. Normally when one cell divides into two, the pair of chromosomes is divided so that one pair goes to one cell and the other cell from one pair to another. In the absence of a change, something went wrong and both chromosomes from one pair entered one cell and no chromosome allowed that pair to enter another.
Most of the time, errors occur randomly during egg or sperm formation. So far, no parental activity or environmental factors are known to cause Down syndrome.
After much research on these cell division errors , the researchers knew that:
– In most cases, an extra copy of chromosome 21 comes from the mother in the egg.
– In a small percentage (less than 5%) of cases, extra copies of chromosome 21 come from the father through sperm.
– In the remaining cases, the error occurs after fertilization, when the embryo develops.
NICHD has launched DS-Connect® as a safe and secure online registry for people with Down syndrome, families and researchers to share information and participate in trials or research. clinical. As families grow, researchers and researchers learn more about Down syndrome and identify similarities and differences in the symptoms and treatments of people with Down syndrome from around the world. gender. The information gathered helps guide future research and treatment. Learn more about DS-Connect®: The Registry of Down Syndrome .
Chromosomal changes may cause the syndrome down
Research shows that three types of chromosome changes can lead to Down syndrome.
– Complete trisomy 21: In this case, an error in egg or sperm formation leads to either having an extra chromosome. So, after the egg and sperm fuse, the obtained cells will also have three copies of chromosome 21. Complete complementary copies of chromosome 21 are in all of his or her cells. a complete trio. Almost all cases of Down syndrome are the result of complete trisomy 21.
– Mosaic tris omy 21: Not every cell in the body is identical. In a small percentage (less than 5%) of Down syndrome, most cells in the body have extra chromosomes, but some of them are not . This is called ” mosaic.” Trisomy 21 can occur when cell division errors occur early in development but after normal sperm and egg coalesce. It can also occur early in development when some cells lose an extra chromosome 21 present at conception. The symptoms of people with trisomy 21 may differ from those with trisomy 21 completely or trisomy 21, depending on the number of cells with more chromosomes.
– Transposition trisomy 21: In this type of chromosome change, only part of the extra copy of chromosome 21 is in the cells. The complement of chromosomes gets “stuck” with other chromosomes and is transferred to other cells as the cells divide. This type of change causes a small number of Down syndrome. There were no cognitive or medical differences between people with 21 and telecom patients with trisomy 21.
Sometimes, parents who do not have Down syndrome can carry a translocation in chromosome 21 that can be passed on to their children and cause Down syndrome. A parent’s chromosomal study can reveal whether this is the cause of the syndrome. A genetic counselor can assist families affected by trisomy 21 movement in understanding the risk of Down syndrome in future pregnancies.
Who is at risk for Down syndrome?
Down syndrome is the most common chromosomal mutation of mild to moderate intellectual disability, and it occurs in all ethnic and economic groups.
Researchers know some, but not all, risk factors for Down syndrome. For example, parents with children with Down syndrome or other chromosomal disorders, or themselves with chromosomal disorders, are more likely to have children with Down syndrome.
In many countries , demographic factors also affect the risk of babies born with Down syndrome. These factors include geographic area, maternal education, moderate status and ethnicity.
Because the probability of an egg containing an extra copy of chromosome 21 increases significantly as women age, older women are more likely than women born to children with Down syndrome. This ability increases as age increases. The CDC provides an analysis of the risk of Down syndrome by mother’s age. Older mothers are more likely to have children affected by Down syndrome than younger mothers. In other words, the incidence of Down syndrome increases as the mother’s age increases. Rate is an estimate of how often a situation occurs between a given group of people. To estimate the prevalence of Down syndrome, the number of pregnancies affected by Down syndrome was compared to the total number of live births.
How do healthcare providers diagnose Down syndrome?
Health care providers can check for Down syndrome during pregnancy or after a baby is born. There are two types of tests for Down syndrome during pregnancy:
– A prenatal screening test. This test may show an increased ability of the fetus with Down syndrome, but it cannot determine whether Down syndrome is definitely present. If screening tests show increased likelihood, diagnostic tests may be required.
– A prenatal diagnostic test. This test can ascertain that Down syndrome is present. Diagnostic tests pose a greater risk to the fetus than screening tests.
The American Congress of Obstetricians and Gynecologists (ACOG) recommends that all pregnant women be screened for Down syndrome.
Prenatal screening for Down Syndrome
There are several options for screening for Down syndrome. Including:
– Blood tests and ultrasound tests in the first trimester of pregnancy. This is the most accepted approach to screening in the first three months. A blood test allows a healthcare provider to check for “signs”, such as certain proteins, in the mother’s blood that indicates an increased likelihood of Down syndrome. The health care provider then performs an ultrasound test, which uses high frequency sound waves to create images. Ultrasound can detect fluid on the back of the fetus’ neck, sometimes indicating Down syndrome. The ultrasound test is called nuchal opacity measurement. In the first trimester, this combination method yields an effective detection rate or equivalent to that used in the second trimester.
– Blood tests in the second trimester of pregnancy. As in the first three months, a blood test allows a health care provider to check for signs of a mother’s blood. A three screen searches for levels of three different markers; a four-fold screen finds levels of four different markers.
– A combined test (sometimes called an integration test). This method uses both blood and ultrasound tests in the first trimester as well as blood tests in the second trimester. Health care providers then combine all of these results to create a Down syndrome risk assessment.
– Non-invasive prenatal screening (NIPT), the most advanced screening method available today, only with the collection of blood of pregnant women from week 10 onwards, analysis of fetal free DNA in maternal blood at risk for Down syndrome. The result has an extremely high accuracy of 99.9 %.
If a woman is pregnant with multiple pregnancies , the blood test will not be reliable because substances from the fetus with Down syndrome may be harder to detect.
Prenatal diagnostic test for Down Syndrome
If a screening test shows the possibility of Down syndrome, a diagnostic test may be done. ACOG recommends that pregnant women of all ages be given the option to skip screening tests and diagnostic tests first. Until recently, only women over 35 and other at-risk women were offered this option because diagnostic tests had a slight risk of miscarriage. Before a diagnostic test, a pregnant woman and her family may want to see a genetic counselor to discuss their family history and the risks and benefits of testing in a given situation. their.
The Down syndrome diagnosis test involves the removal of a sample of genetic material. After being removed, the sample is examined for additional material from chromosome 21, which may indicate that the fetus has Down syndrome. Parents usually receive test results one or two weeks later. The following procedure is used to extract samples.
– Amniocentesis was inserted. A health care provider takes a sample of amniotic fluid, which is then tested for additional chromosomes. This test cannot be done until weeks 14 to 18 of pregnancy.
– Chorionic Villus sampling (CVS). A health care provider takes a sample of cells from a part of the placenta, which connects the woman and the fetus, then tests the sample for more chromosomes. This test is done between weeks 9 and 11 of pregnancy.
– Umbilical blood sampling (PUBS). A health care provider takes a sample of the fetus’ blood in the umbilical cord through the uterus. The blood is then examined for additional chromosomes. PUBS is the most accurate diagnostic method and can confirm CVS results or amniocentesis. However, PUBS cannot be played until the end of the term, during weeks 18 to 22.
Prenatal diagnostic testing is associated with a number of risks for the mother and fetus, including the risk of a slight miscarriage. If you and your family are considering a prenatal diagnosis test for Down syndrome, discuss all risks and benefits with your health care provider.
Testing for chromosomes through maternal blood
A pregnant woman at risk of having a baby with Down syndrome can also have a chromosome test with her blood. A mother’s blood carries DNA from the fetus, which may show additional chromosome 21 material. A more invasive test then will usually confirm a blood test.
Testing and in vitro fertilization
Another approach to diagnosis is used in combination with in vitro fertilization. Ch hidden genetic guess money transplantation (PGT ) allows clinicians to detect an imbalance of chromosomes or other genetic conditions in the fertilized egg before it is implanted in the uterus.
This technique is mainly useful for couples at risk of many inherited diseases, including X-related disorders, as well as couples who have spontaneous abortion, couples who have fertility or people at risk for genetic disorders.
Those interested PGT should get genetic counseling and should look closely monitored and additional tests during their pregnancy, increases the risk of chromosomal abnormalities can arise secondary during t spy In Vitro Fertilisation.
Diagnosis of Down syndrome after birth
Diagnosis of Down syndrome after birth is usually based on the physical signs of the syndrome .
But because people with Down syndrome may not have these symptoms and because many of these symptoms are common in the general population, health care providers will take a sample of your baby’s blood to identify. diagnose. Blood samples are analyzed to determine the baby’s chromosome number .
What are the common treatments for Down syndrome?
There is no single, standard treatment for Down syndrome. The treatment is based on an individual’s physical and intellectual needs as well as their individual strengths and limitations. People with Down syndrome can be properly cared for when living at home and in the community.
A child with Down syndrome may receive care from a group of health professionals, including, but not limited to, doctors, special educators, speech therapists, and physiotherapists. Occupation, physiotherapy and social workers. All professionals interacting with children with Down syndrome should provide stimulation and encouragement.
People with Down syndrome are at a higher risk for some health problems and conditions than those without Down syndrome. Many of these conditions may require immediate postpartum care, infrequent treatment during infancy and adolescents, or long-term treatment throughout life. For example, an infant with Down syndrome may need surgery a few days after birth to correct a heart defect; or a person with Down syndrome may have a digestive problem that requires special diets for a lifetime.
Children, adolescents, and adults with Down syndrome also need regular medical care like those without the disease, from newborn visits and routine vaccinations when newborns come to reproductive counseling and Cardiovascular care later in life. Like others, they also benefit from regular physical and social activity.
– Early intervention and educational therapy
– Therapeutic therapy
– Medicines and dietary supplements
– Device support
* Early intervention and educational therapy
Early intervention, refers to a range of specialized programs and resources that professionals provide to children with Down syndrome and their families. These professionals may include special educators, speech therapists, occupational therapists, physiotherapists and social workers.
Research shows that early intervention helps improve outcomes for children with Down syndrome. This support can begin right after birth and usually continues until the child reaches the age of 3. After that age, most children get intervention and treatment through their local school district.
The following information may be helpful for those who are considering educational support programs for children with Down syndrome:
Children with Down syndrome can attend a school for children with special needs. Parents can choose between a school where most children do not have disabilities and one child has special needs. Educators and health care providers can help families decide which environment is best. Integration into a normal school has become much more common in recent decades .
* Therapeutic therapy
A range of therapies can be used in early intervention and throughout a person’s life to promote development, independence and the highest possible productivity. Some of the laws are listed below.
– Physical therapy includes activities and exercises that help build motor skills, increase muscle strength and improve posture and balance.
+ Physical therapy is important, especially early in life, because physical ability lays the foundation for other skills. The ability to flip, crawl and reach out helps babies learn about the world around them and how to interact with it.
+ A physical therapist can also help a child with Down syndrome compensate for physical challenges, such as low muscle tone, in ways that avoid long-term problems. For example, a physical therapist can help a child establish an effective walk, rather than a pattern that can lead to leg pain.
– Speech therapy can help children with Down syndrome improve communication skills and use language more effectively.
+ Children with Down syndrome often learn to speak later than their peers. A speech language therapist can help them develop the initial skills needed for communication, such as mimicking sound. Therapists can also help with breastfeeding because breastfeeding can increase the muscle mass used to speak.
+ In many cases, children with Down syndrome understand language and want to communicate before they can speak. A speech language therapist can help children use alternative means of communication, such as sign language and pictures, until they learn to speak.
+ Learning to communicate is an ongoing process, so a person with Down syndrome can also benefit from language and language therapy at school as well as later in life. The therapist can help with conversation skills , pronunciation skills , understand what is read, learn and memorize words.
– Occupational therapy helps find ways to adjust daily tasks and conditions to fit a person’s needs and abilities.
+ This type of therapy teaches self-care skills like eating, dressing, writing and using a computer.
+ An occupational therapist can provide special tools that can help improve everyday function, such as a pencil that is easier to hold.
+ At the high school level, an occupational therapist can help young people identify jobs, careers or skills that match their interests and strengths.
– Emotional and behavioral therapies work to find helpful responses to both desired and unwanted behaviors. Children with Down syndrome may become frustrated because of difficulty communicating, may develop compulsive behaviors and may have Attention Deficit Hyperactivity Disorder and other mental health issues. These therapists try to understand why a child is acting, creating ways and strategies to avoid or prevent these situations from happening, and teach better or more positive ways to cope. with situations.
+ A psychologist, counselor or other mental health professional can help a child cope with emotions and build coping and communication skills.
+ Changes in hormone levels experienced by teenagers during puberty can make them more aggressive. Behavioral therapists can help teens identify their intense emotions and teach them healthy ways to achieve a sense of calm.
+ Parents can also benefit from guidance on how to help children with Down syndrome manage daily challenges and reach their full potential.
* Medicines and dietary supplements
Some people with Down syndrome take an amino acid supplement or medication that affects their brain activity. However, many recent clinical trials of these treatments are poorly controlled and show side effects from these treatments. Since then, newer, more special neurological drugs have been developed. However, no controlled clinical study of drugs for the treatment of Down syndrome has proven their safety and effectiveness.
Many studies of drugs to treat the symptoms of dementia in Down syndrome include only a few participants. The results of these studies also do not show clear benefits of these drugs. Similarly, studies of antioxidants for dementia in Down syndrome have shown that these supplements are safe, but ineffective.
* Device support
Increasingly, interventions for children with Down syndrome involve assistive devices, any type of materials, equipment, tools or technology that enhance learning or help complete easier task. Examples include amplifiers for hearing problems, motion strips, special pencils to make writing easier, a touchscreen computer and a computer with a large text keyboard.
* DS-Connect®: Registry of Down Syndrome
Parents and families of children with Down syndrome can connect with other families and people with Down syndrome from around the world to learn more and share information. The NICHD-led DS-Connect is a safe and confidential registry to help families and researchers identify the similarities and differences in the symptoms and treatments of people with Down syndrome and future research guidelines. Learn more about DS-Connect®: The Registry of Down Syndrome.
1- Reference geneticist. (2008). Down syndrome . Retrieved June 11, 2012, from http://ghr.nlm.nih.gov/condition/down-sy Symptoms
2- CDC. (2011). The truth about Down syndrome . Retrieved June 11, 2012, from http://www.cdc.gov/ncbddd/birthdefects/DownSyathy.html
3- CDC. (2012). World Down syndrome day . Retrieved June 11, 2012, from http://www.cdc.gov/ncbddd/birthdefects/features/DownSyathyWorldDay-2012.html
4- NDSS. (the second time). Syndrome down the information board . Retrieved June 11, 2012, from http://www.ndss.org/Down-Syathy/Down-Syathy-Facts/
5- Bull, MJ, and the Commission on Genetics. (2011). Health monitoring for children with Down syndrome. Pediatrics , 128, 393 Electrical 406.
6- Down syndrome. (2012). In the ADAM medical encyclopedia. Retrieved June 11, 2012, from http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001992
7- Ulrich, DA, Burghardt, AR, Lloyd, M., Tiernan, C., & Hornyak, JR (2011) Physical activity of learning to ride a bicycle for children with Down syndrome: Randomized trial. Physiotherapy , 91, 1463 Picture 1477.
8- Martin, GE, Klusek, J., Estigarribia, B., & Roberts, JE (2009). Linguistic characteristics of individuals with Down syndrome Topics about Language disorders, 29 (2), 112 Tai132.
9- Parker, SE, Mai, CT, Canfield, MA, Rickard, R., Wang, Y., Meyer, RE, et al. (2010). Updated estimate of national prevalence of birth defects selected in the United States, 20042002006. Studying birth defects. Part A, Clinical and Molecular Physiology , 88, 1008 matches 1016.
10- Center for information on genetic and rare diseases (GARD). (2012). Down syndrome . Retrieved June 11, 2012, from http://raredisease.info.nih.gov/GARD/QnASelected.aspx?diseaseID=10247
11- Davidson, MA (2008). Primary care for children and adolescents with Down syndrome. North American Pediatric Clinic , 55, 1099 Hay1111.
12- Egan, JF, Smith, K., Timms, D., Bolnick, JM, Campbell, WA, & Benn, PA (2011). Demographic differences in births in Down syndrome in the US from 1989 to 2006. Prenatal diagnosis , 31, 389 Counter 394.
13- Livingston, G. & Cohn, D. (2010). New demographics of American motherhood. Pew Research Center . Retrieved July 23, 2011, from http://www.pewsocialtrends.org/2010/05/06/the-new-demography-of-american-othershood/
14- Morris, JK, Wald, NJ, Mutton, DE, & Alberman, E. (2003). Compare age-specific risk patterns for mothers with Down syndrome born. Prenatal diagnosis , 23, 252 Article 258.
15- American Congress of Obstetricians and Gynecologists (ACOG). (2007, May 7). ACOG screening guide for chromosomal abnormalities [News release] . Retrieved June 11, 2012.
16- Driscoll, DA, & Gross, S. (2009). Prenatal screening for aneuploidy. New England Journal of Medicine , 360, 2556 212525.
17- Ehrich, M., Deciu, C., Zwiefelhofer, C., Ty Nam, JA, Cagasan, L., Tim, R., Lu, V., et al. (2011). Detecting non-invasive trisomy 21 of the fetus by DNA sequencing in maternal blood: A study in clinical setting. American Journal of Obstetrics & Gynecology , 204, 20112211.
18- ACOG. (2011). Routine tests during pregnancy . Retrieved June 11, 2012, from http://www.acog.org/~/media/For%20Patents/faq133.pdf?dmc=1&ts=20120611T1510306056 (PDF – 218.20 KB)
19- American Society of Clinical Chemistry. (2012). Second trimester: Cordrialesis (percutaneous umbilical cord sampling, PUBS) . Retrieved June 11, 2012, from https://labtestsonline.org/conditions/pregnancy-second-trimester-13-27-week
20- Caughey, AB, Hopkins, LM, & Norton, ME (2006). Sampling of chorionic villi versus amniocentesis and the difference in incidence of miscarriage. Obstetrics and Gynecology , 108, 612 Hay616.
21- Evans, MI, & Wapner, RJ (2005). Invasive prenatal diagnostic procedure in 2005. Seminars on Perinatology , 29, 215 Tu218.
22- Daniilidis, A., Karydas, H., Zournatzi, V., Tantanocation, T., Giannoulis, C., & Tzafettas, J. (2008). A four-year retrospective study of amniocentesis: A central experience. Hippokratia , 12, 113 Hang115 .
23- ACOG. (2007). Practical news of ACOG: Invasive prenatal testing for idiopathic treatment . Retrieved June 11, 2012, from https://www.ncbi.nlm.nih.gov/pubmed/18055749 (PDF – 160 KB)
24- Hanna, KE (2006). Genetic testing . Retrieved June 11, 2012, from the website of the National Human Genome Research Institute: http://www.genome.gov/10004766
25- National Human Genome Research Institute. (2010). Learn about Down syndrome . Retrieved June 11, 2012, from http://www.genome.gov/19517824#3
26- National Human Genome Research Institute. (2010). Learn about Down syndrome . Retrieved June 11, 2012, from http://www.genome.gov/19517824
27- Guralnick, MJ (2010). Early intervention for strengthening social capacity related to children with developmental delays: A historical perspective. Infants and young children , 23, 73 Hang83.
28- Guralnick, MJ (2011). Why early intervention works: A systematic perspective. Infants and young children , 24, 6 balls28.
29- Winders, PC (nd). Rough motor development and Down syndrome . Retrieved June 11, 2012, from the NDSS website: http://www.ndss.org/en/Education-Development–Community-Life/Therapies–Development/Physical–Occupational-Theracco/#gross
30- Kumin, L. (nd). Speech and language skills in babies, toddlers and young children with Down syndrome . Retrieved June 11, 2012, from the NDSS website: http://www.ndss.org/resource/speech-lingu-theracco/
31- Costa, AC (2011). Under the promise of medicinal herbs targeting cognitive and neurodegenerative components of Down syndrome. Developmental neuroscience , 33, 414 Manh427.
32- Kishnani, PS, Heller, JH, Spiridigliozzi, GA, Lott, I., Escobar, L., Richardson, S., Zhang, R., et al. (2010). Donepezil for the treatment of cognitive dysfunction in children with Down syndrome at the age of 101717. American Journal of Medical Genetics Part A , 152A, 3028 From 3035.
33- Mohan, M., Bennett, C., & Carpenter, PK (2009). Memantine for dementia in people with Down syndrome. Burrane system overview database, CD007657.
34- Lott, IT, Doran, E., Nguyen, VQ, Tournay, A., Head, E., & Gillen, DL (2011). Down syndrome and dementia: a randomized, controlled trial of antioxidant supplements. American Journal of Medical Genetics Part A , 155A, 1939 191948.