Down's syndrome (DS) is the most common genetic form of intellectual disability and has a rich history of research conducted over many decades. Research continues to progress, and new knowledge continues to emerge to improve the quality of life of individuals with DS. To support the development of a person with DS, it is critical to provide early interventional therapies, educational resources, optimal community involvement, and ongoing medical screening and treatment when appropriate.
The average life expectancy is about 50-60 years and continues to improve, as a result of advances in medical treatment and educational and community resources.[64]Baird PA, Sadovnick AD. Life expectancy in Down syndrome adults. Lancet. 1988;2:1354-6.
http://www.ncbi.nlm.nih.gov/pubmed/2904063?tool=bestpractice.com
[65]Yang Q, Rasmussen SA, Friedman JM. Mortality associated with Down's syndrome in the USA from 1983 to 1997: a population-based study. Lancet. 2002;359:1019-25.
http://www.ncbi.nlm.nih.gov/pubmed/11937181?tool=bestpractice.com
Factors such as heart defects, prematurity, low birth weights, respiratory complications, coronary artery disease, leukaemia, racial/ethnic background, and Alzheimer-type dementia influence the mortality risk.[66]Rasmussen SA, Wong LY, Correa A, et al. Survival in infants with Down syndrome, Metropolitan Atlanta, 1979-1998. J Pediatr. 2006;148:806-12.
http://www.ncbi.nlm.nih.gov/pubmed/16769392?tool=bestpractice.com
[67]Bittles AH, Bower C, Hussain R, et al. The four ages of Down syndrome. Eur J Public Health. 2007;17:221-5.
http://www.ncbi.nlm.nih.gov/pubmed/16857692?tool=bestpractice.com
[68]Glasson EJ, Jacques A, Wong K, et al. Improved survival in Down syndrome over the last 60 years and the impact of perinatal factors in recent decades. J Pediatr. 2016;169:214-20.
http://www.jpeds.com/article/S0022-3476(15)01322-0/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/26651430?tool=bestpractice.com
[69]Wang Y, Liu G, Canfield MA, et al. Racial/ethnic differences in survival of United States children with birth defects: a population-based study. J Pediatr. 2015;166:819-26.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4696483
http://www.ncbi.nlm.nih.gov/pubmed/25641238?tool=bestpractice.com
Secondary sex characteristics in girls with DS develop in the same sequence as in typical children, with age of menarche at about 12.5 years. Women with DS can become pregnant, and their children have a 50% chance of having DS. Research on fertility in individuals with DS has been limited, and knowledge on this issue remains unclear.[5]Hunter AGW. Down syndrome. In: Cassidy SB, Allanson JE, eds. Management of genetic syndromes, 2nd ed. Hoboken, NJ: Wiley-Liss; 2005:191-210.[35]Van Cleve SN, Cannon S, Cohen WI. Part II: clinical practice guidelines for adolescents and young adults with Down syndrome: 12 to 21 years. J Pediatr Health Care. 2006;20:198-205.
http://www.ncbi.nlm.nih.gov/pubmed/16675381?tool=bestpractice.com