Back Down-Syndrom ALS Sindrome de Down AN متلازمة داون Arabic ডাউন চিন্দ্ৰম Assamese Síndrome de Down AST Daun sindromu Azerbaijani داون سندرومو AZB Синдром на Даун Bulgarian ডাউন সিনড্রোম Bengali/Bangla Downov sindrom BS

Down syndrome

Down syndrome
Other namesDown's syndrome, Down's, trisomy 21
Eight year old boy with Down syndrome
An eight-year-old boy displaying characteristic facial features of Down syndrome
SpecialtyMedical genetics, pediatrics
SymptomsDelayed development, characteristic physical features, mild to moderate intellectual disability[1]
Usual onsetMostly at conception, rarely after fertilization[2]
DurationLifelong
CausesThird copy of chromosome 21[3]
Risk factorsOlder age of mother, prior affected child[4][5]
Diagnostic methodPrenatal screening, genetic testing[6]
TreatmentPhysical therapy, Occupational therapy, Speech therapy, Educational support, Supported work environment[7][8]
PrognosisLife expectancy 50 to 60 years (developed world)[9][10]
Frequency5.4 million (0.1%)[1][11]
Named afterJohn Langdon Down

Down syndrome or Down's syndrome,[12] also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21.[3] It is usually associated with developmental delays, mild to moderate intellectual disability, and characteristic physical features.[1][13]

The parents of the affected individual are usually genetically normal.[14] The incidence of the syndrome increases with the age of the mother, from less than 0.1% for 20-year-old mothers to 3% for those of age 45.[4] It is believed to occur by chance, with no known behavioral activity or environmental factor that changes the probability.[2] Usually, babies get 23 chromosomes from each parent for a total of 46, whereas in Down syndrome, a third 21st chromosome is attached.[15] The extra chromosome is provided at conception as the egg and sperm combine.[16] In 1–2% of cases, the additional chromosome is added in the embryo stage and only impacts some of the cells in the body; this is known as Mosaic Down syndrome.[17][15] Translocation Down syndrome is another rare type.[18][19] Down syndrome can be identified during pregnancy by prenatal screening, followed by diagnostic testing, or after birth by direct observation and genetic testing.[6] Since the introduction of screening, Down syndrome pregnancies are often aborted (rates varying from 50 to 85% depending on maternal age, gestational age, and maternal race/ethnicity).[20][21][22]

As of 2024, there is no known cure for Down syndrome.[23] Education and proper care have been shown to provide better quality of life.[7] Some children with Down syndrome are educated in typical school classes, while others require more specialized education.[8] Some individuals with Down syndrome graduate from high school, and a few attend post-secondary education.[24] In adulthood, about 20% in the United States do some paid work,[25] with many requiring a sheltered work environment.[8] Caretaker support in financial and legal matters is often needed.[10] Life expectancy is around 50 to 60 years in the developed world, with proper health care.[9][10] Regular screening for health issues common in Down syndrome is recommended throughout the person's life.[9]

Down syndrome is the most common chromosomal abnormality,[26] occurring in about 1 in 1,000 babies born worldwide,[1] and one in 700 in the US.[18] In 2015, there were 5.4 million people with Down syndrome globally, of whom 27,000 died, down from 43,000 deaths in 1990.[11][27][28] The syndrome is named after British physician John Langdon Down, who fully described it in 1866.[29] Some aspects were described earlier by French psychiatrist Jean-Étienne Dominique Esquirol in 1838 and French physician Édouard Séguin in 1844.[30] The genetic cause was discovered in 1959.[29]

  1. ^ a b c d Weijerman ME, de Winter JP (December 2010). "Clinical practice. The care of children with Down syndrome". European Journal of Pediatrics. 169 (12): 1445–1452. doi:10.1007/s00431-010-1253-0. PMC 2962780. PMID 20632187.
  2. ^ a b "What causes Down syndrome?". National Institute of Child Health and Human Development. U.S. National Institutes of Health. 2014-01-17. Archived from the original on 5 January 2016. Retrieved 6 January 2016.
  3. ^ a b Patterson D (July 2009). "Molecular genetic analysis of Down syndrome". Human Genetics. 126 (1): 195–214. doi:10.1007/s00439-009-0696-8. ISSN 0340-6717. PMID 19526251. S2CID 10403507.
  4. ^ a b Cite error: The named reference Mor2002 was invoked but never defined (see the help page).
  5. ^ "Down syndrome – Symptoms and causes". Mayo Clinic. Retrieved 17 March 2019.
  6. ^ a b "How do health care providers diagnose Down syndrome?". Eunice Kennedy Shriver National Institute of Child Health and Human Development. 2014-01-17. Archived from the original on 7 March 2016. Retrieved 4 March 2016.
  7. ^ a b Roizen NJ, Patterson D (April 2003). "Down's syndrome". Lancet (Review). 361 (9365): 1281–1289. doi:10.1016/S0140-6736(03)12987-X. PMID 12699967. S2CID 33257578.
  8. ^ a b c "Facts About Down Syndrome". National Association for Down Syndrome. Archived from the original on 3 April 2012. Retrieved 20 March 2012.
  9. ^ a b c Malt EA, Dahl RC, Haugsand TM, Ulvestad IH, Emilsen NM, Hansen B, et al. (February 2013). "Health and disease in adults with Down syndrome". Tidsskrift for den Norske Laegeforening. 133 (3): 290–294. doi:10.4045/tidsskr.12.0390. PMID 23381164.
  10. ^ a b c Kliegma RM (2011). "Down Syndrome and Other Abnormalities of Chromosome Number". Nelson textbook of pediatrics (19th ed.). Philadelphia: Saunders. pp. Chapter 76.2. ISBN 978-1-4377-0755-7.
  11. ^ a b GBD 2015 Disease and Injury Incidence and Prevalence Collaborators (October 2016). "Global, regional, and national incidence, prevalence, and years lived with disability for 310 diseases and injuries, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015". Lancet. 388 (10053): 1545–1602. doi:10.1016/S0140-6736(16)31678-6. PMC 5055577. PMID 27733282.
  12. ^ Cite error: The named reference Smith-2011 was invoked but never defined (see the help page).
  13. ^ "What are common symptoms of Down syndrome?". NIH Eunice Kennedy Shriver National Institute of Child Health and Human Development. 31 January 2017. Retrieved 28 March 2023.
  14. ^ Hammer GD (2010). "Pathophysiology of Selected Genetic Diseases". In McPhee SJ (ed.). Pathophysiology of disease: an introduction to clinical medicine (6th ed.). New York: McGraw-Hill Medical. pp. Chapter 2. ISBN 978-0-07-162167-0.
  15. ^ a b "The Genetics of Down's Syndrome". www.intellectualdisability.info. Retrieved 2023-04-01.
  16. ^ "Facts About Down Syndrome". National Association for Down Syndrome. Retrieved 2023-04-01.
  17. ^ "LSUHSC School of Medicine". www.medschool.lsuhsc.edu. Retrieved 2023-04-01.
  18. ^ a b Cite error: The named reference CDC was invoked but never defined (see the help page).
  19. ^ "About Down Syndrome | National Down Syndrome Society (NDSS)". ndss.org. Retrieved 2023-03-28.
  20. ^ Seror V, L'Haridon O, Bussières L, Malan V, Fries N, Vekemans M, et al. (March 2019). "Women's Attitudes Toward Invasive and Noninvasive Testing When Facing a High Risk of Fetal Down Syndrome". JAMA Network Open. 2 (3): e191062. doi:10.1001/jamanetworkopen.2019.1062. PMC 6450316. PMID 30924894.
  21. ^ Natoli JL, Ackerman DL, McDermott S, Edwards JG (February 2012). "Prenatal diagnosis of Down syndrome: a systematic review of termination rates (1995-2011)". Prenatal Diagnosis. 32 (2): 142–153. doi:10.1002/pd.2910. PMID 22418958.
  22. ^ Mansfield C, Hopfer S, Marteau TM (September 1999). "Termination rates after prenatal diagnosis of Down syndrome, spina bifida, anencephaly, and Turner and Klinefelter syndromes: a systematic literature review. European Concerted Action: DADA (Decision-making After the Diagnosis of a fetal Abnormality)". Prenatal Diagnosis. 19 (9). Wiley: 808–812. doi:10.1002/(sici)1097-0223(199909)19:9<808::aid-pd637>3.0.co;2-b. PMID 10521836. S2CID 29637272.
  23. ^ "Down Syndrome: Other FAQs". 2014-01-17. Archived from the original on 6 January 2016. Retrieved 6 January 2016.
  24. ^ Steinbock B (2011). "The Risk of Transmitting Disease or Disability". Life before birth the moral and legal status of embryos and fetuses (2nd ed.). Oxford: Oxford University Press. p. 222. ISBN 978-0-19-971207-6. Archived from the original on 2017-01-23.
  25. ^ Szabo L (May 9, 2013). "Life with Down syndrome is full of possibilities". USA Today. Archived from the original on 8 January 2014. Retrieved 7 February 2014.
  26. ^ Martínez-Espinosa RM, Molina Vila MD, Reig García-Galbis M (June 2020). "Evidences from Clinical Trials in Down Syndrome: Diet, Exercise and Body Composition". International Journal of Environmental Research and Public Health. 17 (12): 4294. doi:10.3390/ijerph17124294. PMC 7344556. PMID 32560141.
  27. ^ GBD 2015 Mortality and Causes of Death Collaborators (October 2016). "Global, regional, and national life expectancy, all-cause mortality, and cause-specific mortality for 249 causes of death, 1980-2015: a systematic analysis for the Global Burden of Disease Study 2015". Lancet. 388 (10053): 1459–1544. doi:10.1016/s0140-6736(16)31012-1. PMC 5388903. PMID 27733281.
  28. ^ GBD 2013 Mortality and Causes of Death Collaborators (January 2015). "Global, regional, and national age-sex specific all-cause and cause-specific mortality for 240 causes of death, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013". Lancet. 385 (9963): 117–171. doi:10.1016/S0140-6736(14)61682-2. PMC 4340604. PMID 25530442.
  29. ^ a b Hickey F, Hickey E, Summar KL (2012). "Medical update for children with Down syndrome for the pediatrician and family practitioner". Advances in Pediatrics. 59 (1). Elsevier BV: 137–157. doi:10.1016/j.yapd.2012.04.006. PMID 22789577.
  30. ^ Evans-Martin FF (2009). Down syndrome. New York: Chelsea House. p. 12. ISBN 978-1-4381-1950-2.

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