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75-478: The National Down Syndrome Society ( NDSS ) is an American organization that offers support to people with Down syndrome , their families, friends, teachers, and coworkers, and educates the general public about Down syndrome. The mission of the NDSS is to be the leading human rights organization for all individuals with Down syndrome. The NDSS was founded by Betsy Goodwin and Arden Moulton. Goodwin's daughter, Carson

150-430: A Robertsonian translocation , isochromosome , or ring chromosome . These contain additional material from chromosome 21 and occur in about 2.5% of cases. An isochromosome results when the two long arms of a chromosome separate together rather than the long and short arm separating together during egg or sperm development . Down syndrome (also known by the karyotype 47,XX,+21 for females and 47,XY,+21 for males)

225-481: A single crease of the palm , and short fingers. Instability of the atlantoaxial joint occurs in about 1–2%. Atlantoaxial instability may cause myelopathy due to cervical spinal cord compression later in life, this often manifests as new onset weakness, problems with coordination , bowel or bladder incontinence, and gait dysfunction. Serial imaging cannot reliably predict future cervical cord compression, but changes can be seen on neurological exam. The condition

300-526: A 'human right and a civil right.' Nonetheless, it is unfortunate that a leading Down syndrome advocacy group is promoting a belief system over evidence-based methods that work." Down syndrome Down syndrome or Down's syndrome , also known as trisomy 21 , is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21 . It is usually associated with developmental delays, mild to moderate intellectual disability , and characteristic physical features. The parents of

375-504: A 1% possibility of having a second child with the syndrome, if both parents are found to have normal karyotypes . The extra chromosome content can arise through several different ways. The most common cause (about 92–95% of cases) is a complete extra copy of chromosome 21, resulting in trisomy 21. In 1–2.5% of cases, some of the cells in the body are normal and others have trisomy 21, known as mosaic Down syndrome. The other common mechanisms that can give rise to Down syndrome include:

450-544: A child with Down syndrome when the mother is affected and a less than 5% probability if the father is affected. The probability of this type of Down syndrome is not related to the mother's age. Some children without Down syndrome may inherit the translocation and have a higher probability of having children of their own with Down syndrome. In this case it is sometimes known as familial Down syndrome. The extra genetic material present in Down syndrome results in overexpression of

525-669: A country. This situation tends to lower the ranking of some of the most advanced countries, such as the G7 members and others. According to the United Nations Statistics Division : There is no established convention for the designation of "developed" and "developing" countries or areas in the United Nations system. And it notes that: The designations "developed" and "developing" are intended for statistical convenience and do not necessarily express

600-399: A false-positive rate of 2–5%. If Down syndrome occurs in one in 500 pregnancies with a 90% detection rate and the test used has a 5% false-positive rate, this means, of 20 women who test positive on screening, only one will not have a fetus with Down syndrome confirmed. If the screening test has a 2% false-positive rate, this means, of 50 women who test positive on screening, one will not have

675-424: A fetus with Down syndrome. Developed world A developed country , or advanced country , is a sovereign state that has a high quality of life , developed economy , and advanced technological infrastructure relative to other less industrialized nations. Most commonly, the criteria for evaluating the degree of economic development are the gross domestic product (GDP), gross national product (GNP),

750-474: A few attend post-secondary education . In adulthood, about 20% in the United States do some paid work, with many requiring a sheltered work environment. Caretaker support in financial and legal matters is often needed. Life expectancy is around 50 to 60 years in the developed world , with proper health care. Regular screening for health issues common in Down syndrome is recommended throughout

825-662: A group of officials from major creditor countries whose role is to find coordinated and sustainable solutions to the payment difficulties experienced by debtor countries. 15 countries in Europe: three countries in the Americas: three countries in Asia: one country in Oceania: Comparative table of countries with a "very high" human development (0.800 or higher), according to UNDP ; "advanced" economies, according to

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900-480: A high likelihood of trisomy 21. Accuracy has been reported at 98.6% in the first trimester of pregnancy. Confirmatory testing by invasive techniques (amniocentesis, CVS) is still required to confirm the screening result. For combinations of ultrasonography and non-genetic blood tests, screening in both the first and second trimesters is better than just screening in the first trimester. The different screening techniques in use are able to pick up 90–95% of cases, with

975-799: A judgement about the stage reached by a particular country or area in the development process. Nevertheless, the UN Trade and Development considers that this categorization can continue to be applied: The developed economies broadly comprise Northern America and Europe, Israel, Japan, the Republic of Korea, Australia, and New Zealand. Terms linked to the concept developed country include "advanced country", "industrialized country", "more developed country" (MDC), "more economically developed country" (MEDC), " Global North country", " first world country", and "post-industrial country". The term industrialized country may be somewhat ambiguous, as industrialisation

1050-454: A keyboard. Many masked independent tests and studies have suggested that the facilitator is actually the one doing the typing, and not the person with the disability. Stuart Vyse , reporting for Skeptical Inquirer , commented that "Given NDSS's mission of being 'The leading human rights organization for all individuals with Down syndrome,' it is not surprising the organization supports a communication method that [Christy] Ashby [PhD] described as

1125-518: A lower risk of hardening of the arteries . Although the overall risk of cancer in Down syndrome is not changed, the risk of testicular cancer and certain blood cancers, including acute lymphoblastic leukemia (ALL) and acute megakaryoblastic leukemia (AMKL) is increased while the risk of other non-blood cancers is decreased. People with Down syndrome are believed to have an increased risk of developing cancers derived from germ cells whether these cancers are blood- or non-blood-related. In 2008,

1200-415: A male affected with Down syndrome, it results in a karyotype of 46XY,t(14q21q). This may be a new mutation or previously present in one of the parents. The parent with such a translocation is usually normal physically and mentally; however, during production of egg or sperm cells, a higher chance of creating reproductive cells with extra chromosome 21 material exists. This results in a 15% chance of having

1275-799: A more alkaline saliva resulting in a greater resistance to tooth decay , despite decreased quantities of saliva, less effective oral hygiene habits, and higher plaque indexes. Higher rates of tooth wear and bruxism are also common. Other common oral manifestations of Down syndrome include enlarged hypotonic tongue, crusted and hypotonic lips, mouth breathing , narrow palate with crowded teeth, class III malocclusion with an underdeveloped maxilla and posterior crossbite , delayed exfoliation of baby teeth and delayed eruption of adult teeth, shorter roots on teeth, and often missing and malformed (usually smaller) teeth. Less common manifestations include cleft lip and palate and enamel hypocalcification (20% prevalence). Taurodontism , an elongation of

1350-627: A number of health concerns, such as congenital heart defect , epilepsy , leukemia , and thyroid diseases . People with Down syndrome may have these physical characteristics: a small chin , epicanthic folds , low muscle tone , a flat nasal bridge , and a protruding tongue. A protruding tongue is caused by low tone and weak facial muscles, and often corrected with myofunctional exercises. Some characteristic airway features can lead to obstructive sleep apnea in around half of those with Down syndrome. Other common features include: excessive joint flexibility, extra space between big toe and second toe,

1425-471: A poorly or nonfunctioning thyroid at birth (known as congenital hypothyroidism ) which occurs in 1% or can develop later due to an attack on the thyroid by the immune system resulting in Graves' disease or autoimmune hypothyroidism . Type 1 diabetes mellitus is also more common. Constipation occurs in nearly half of people with Down syndrome and may result in changes in behavior. One potential cause

1500-582: A portion of the 310 genes located on chromosome 21. This overexpression has been estimated at 50%, due to the third copy of the chromosome present. Some research has suggested the Down syndrome critical region is located at bands 21q22.1–q22.3, with this area including genes for the amyloid precursor protein , superoxide dismutase , and likely the ETS2 proto oncogene . Other research, however, has not confirmed these findings. MicroRNAs are also proposed to be involved. The dementia that occurs in Down syndrome

1575-506: A third 21st chromosome is attached. The extra chromosome is provided at conception as the egg and sperm combine. 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 . Translocation Down syndrome is another rare type. Down syndrome can be identified during pregnancy by prenatal screening , followed by diagnostic testing, or after birth by direct observation and genetic testing . Since

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1650-605: A third of cases of intellectual disability. Many developmental milestones are delayed with the ability to crawl typically occurring around 8–22 months rather than 6–12 months, and the ability to walk independently typically occurring around 1–4 years rather than 9–18 months. Walking is acquired in 50% of children after 24 months. Most individuals with Down syndrome have mild (IQ: 50–69) or moderate (IQ: 35–50) intellectual disability with some cases having severe (IQ: 20–35) difficulties. Those with mosaic Down syndrome typically have IQ scores 10–30 points higher than that. As they age,

1725-513: A wide range of emotions. While people with Down syndrome are generally happy, symptoms of depression and anxiety may develop in early adulthood. Children and adults with Down syndrome are at increased risk of epileptic seizures , which occur in 5–10% of children and up to 50% of adults. This includes an increased risk of a specific type of seizure called infantile spasms . Many (15%) who live 40 years or longer develop Alzheimer's disease . In those who reach 60 years of age, 50–70% have

1800-466: Is Hirschsprung's disease , occurring in 2–15%, which is due to a lack of nerve cells controlling the colon . Other congenital problems can include duodenal atresia , imperforate anus and gastroesophageal reflux disease . Celiac disease affects about 7–20%. People with Down syndrome tend to be more susceptible to gingivitis as well as early, severe periodontal disease, necrotising ulcerative gingivitis , and early tooth loss , especially in

1875-497: Is a leukemia of megakaryoblasts , the precursors cells to megakaryocytes which form blood platelets . Acute lymphoblastic leukemia in Down syndrome accounts for 1–3% of all childhood cases of ALL. It occurs most often in those older than nine years or having a white blood cell count greater than 50,000 per microliter and is rare in those younger than one year old. ALL in Down syndrome tends to have poorer outcomes than other cases of ALL in people without Down syndrome. In short,

1950-498: Is an ongoing process that is hard to define. The first industrialized country was the United Kingdom , followed by Belgium . Later it spread further to Germany , United States , France and other Western European countries. According to some economists such as Jeffrey Sachs , however, the current divide between the developed and developing world is largely a phenomenon of the 20th century. Mathis Wackernagel calls

2025-399: Is due to an excess of amyloid beta peptide produced in the brain and is similar to Alzheimer's disease , which also involves amyloid beta build-up. Amyloid beta is processed from amyloid precursor protein, the gene for which is located on chromosome 21. Senile plaques and neurofibrillary tangles are present in nearly all by 35 years of age, though dementia may not be present. It

2100-456: Is hypothesized that those with Down syndrome lack a normal number of lymphocytes and produce less antibodies which is said to present an increased risk of infection. Down syndrome is associated with an increased risk of some chronic diseases that are typically associated with older age such as Alzheimer's disease. It is believed that accelerated aging occurs and increases the biological age of tissues, but molecular evidence for this hypothesis

2175-412: Is more accurate. Increased fetal nuchal translucency (NT) indicates an increased possibility of Down syndrome picking up 75–80% of cases and being falsely positive in 6%. Several blood markers can be measured to predict the chances of Down syndrome during the first or second trimester. Testing in both trimesters is sometimes recommended and test results are often combined with ultrasound results. In

2250-408: Is more common with Down syndrome, though the rate may not differ until after twelve months of age compared to children without Down syndrome. Early screening is recommended to identify and treat significant refractive error with glasses or contact lenses. Poor accommodation (ability to focus on close objects) is associated with Down syndrome, which may mean bifocals are indicated. In keratoconus ,

2325-445: Is more often acquired than congenital . Early diagnosis and treatment of strabismus reduces the risk of vision loss from amblyopia. In Down syndrome, the presence of epicanthal folds may give the false impression of strabismus , referred to as pseudostrabismus . Nasolacrimal duct obstruction, which causes tearing ( epiphora ), is more frequently bilateral and multifactorial than in children without Down syndrome. Refractive error

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2400-427: Is mostly caused by a failure of the 21st chromosome to separate during egg or sperm development, known as nondisjunction . As a result, a sperm or egg cell is produced with an extra copy of chromosome 21; this cell thus has 24 chromosomes. When combined with a normal cell from the other parent, the baby has 47 chromosomes, with three copies of chromosome 21. About 88% of cases of trisomy 21 result from nonseparation of

2475-406: Is sparse. According to a biomarker of tissue age known as epigenetic clock , it is hypothesized that trisomy 21 increases the age of blood and brain tissue (on average by 6.6 years). Guidelines recommend screening for Down syndrome to be offered to all pregnant women, regardless of age. A number of tests are used, with varying levels of accuracy. They are typically used in combination to increase

2550-515: Is surgically corrected with spine surgery. Growth in height is slower, resulting in adults who tend to have short stature —the average height for men is 154 centimetres (5 feet 1 inch), and for women is 142 centimetres (4 feet 8 inches). Individuals with Down syndrome are at increased risk for obesity as they age due to hypothyroidism, other medical issues and lifestyle. Growth charts have been developed specifically for children with Down syndrome. This syndrome causes about

2625-509: Is typically preceded by transient myeloproliferative disease (TMD), a disorder of blood cell production in which non-cancerous megakaryoblasts with a mutation in the GATA1 gene rapidly divide during the later period of pregnancy. GATA1 mutations combined with trisomy 21 contribute to a predisposition to TAM. In trisomy 21, the process of leukemogenesis starts in early fetal life, with genetic factors, including GATA1 mutations, contributing to

2700-475: The Human Development Index (HDI), which combines an economic measure, national income, with other measures, indices for life expectancy and education has become prominent. This criterion would define developed countries as those with a very high (HDI) rating. The index, however, does not take into account several factors, such as the net wealth per capita or the relative quality of goods in

2775-476: The IMF . Economic criteria have tended to dominate discussions. One such criterion is the income per capita; countries with the high gross domestic product (GDP) per capita would thus be described as developed countries. Another economic criterion is industrialisation ; countries in which the tertiary and quaternary sectors of industry dominate would thus be described as developed. More recently, another measure,

2850-516: The cornea progressively thins and bulges into a cone shape, causing visual blurring or distortion. Keratoconus first presents in the teen years and progresses into the thirties. Down syndrome is a strong risk factor for developing keratoconus, and onset may be occur at a younger age than in those without Down syndrome. Eye rubbing is also a risk factor for developing keratoconus. It is speculated that chronic eye irritation from blepharitis may increase eye rubbing in Down syndrome, contributing to

2925-795: The per capita income , level of industrialization, amount of widespread infrastructure and general standard of living. Which criteria are to be used and which countries can be classified as being developed are subjects of debate. Different definitions of developed countries are provided by the International Monetary Fund and the World Bank ; moreover, HDI ranking is used to reflect the composite index of life expectancy, education, and income per capita. In 2023 , 40 countries fit all four criteria, while an additional 19 countries fit three out of four. Developed countries have generally more advanced post-industrial economies, meaning

3000-429: The quality of life for those with Down syndrome. In January 2019, the NDSS offered a free public webinar on facilitated communication held by Christine Ashby . This communication method is based on the theory that many people that are unable to speak and are not cognitively impaired, but are simply unable to produce the sounds for speech. A helper or "facilitator" assists by guiding the non-speaking person's hand over

3075-442: The sensorineural type occurs at a much earlier age and affects 10–70% of people with Down syndrome. The rate of congenital heart disease in newborns with Down syndrome is around 40%. Of those with heart disease, about 80% have an atrial septal defect or ventricular septal defect with the former being more common. Congenital heart disease can also put individuals at a higher risk of pulmonary hypertension , where arteries in

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3150-462: The service sector provides more wealth than the industrial sector . They are contrasted with developing countries , which are in the process of industrialisation or are pre-industrial and almost entirely agrarian , some of which might fall into the category of Least Developed Countries . As of 2023 , advanced economies comprise 57.3% of global GDP based on nominal values and 41.1% of global GDP based on purchasing-power parity (PPP) according to

3225-486: The HDI accounts for more than income or productivity. Unlike GDP per capita or per capita income, the HDI takes into account how income is turned "into education and health opportunities and therefore into higher levels of human development." Since 1990, Norway (2001–2006, 2009–2019), Japan (1990–1991 and 1993), Canada (1992 and 1994–2000) and Iceland (2007–2008) have had the highest HDI score. The following countries in

3300-529: The IMF's list of 38 Advanced Economies, noting that the IMF's Advanced Economies list "would presumably also cover the following nine smaller countries of Andorra, Bermuda, Faroe Islands, Guernsey, Holy See, Jersey, Liechtenstein, Monaco, and San Marino[...]". San Marino (2012) and Andorra (2021) were later included in the IMF's list. There are 22 permanent members in the Paris Club ( French : Club de Paris ),

3375-619: The Pacific: According to the World Bank , the following 85 sovereign states and territories across are classified as "high income" economies , having a nominal GDP per capita in excess of $ 14,005 as of 2024: Unsovereign Territories are denoted with an asterisk (*) . There are 29 OECD member countries and the European Union —in the Development Assistance Committee (DAC), a group of

3450-520: The World Health Organization (WHO) introduced a distinct classification for myeloid proliferation in individuals with Down syndrome. Leukemia is 10 to 15 times more common in children with Down syndrome. In particular, acute lymphoblastic leukemia is 20 times more common and the megakaryoblastic form of acute myeloid leukemia ( acute megakaryoblastic leukemia ), is 500 times more common. Acute megakaryoblastic leukemia (AMKL)

3525-819: The addition of 7 microstates and dependencies modified by the CIA which were omitted from the IMF version: 29 countries and dependencies in Europe classified by the IMF, 6 others given by the CIA: Plus seven countries and territories in Asia : three countries and territories in the Americas classified by the IMF, one territory given by the CIA ;: two countries in Oceania : The CIA has modified an older version of

3600-419: The affected individual are usually genetically normal. 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. It is believed to occur by chance, with no known behavioral activity or environmental factor that changes the probability. Usually, babies get 23 chromosomes from each parent for a total of 46, whereas in Down syndrome,

3675-457: The binary labeling of countries as "neither descriptive nor explanatory. It is merely a thoughtless and destructive endorsement of GDP fetish. In reality, there are not two types of countries, but over 200 countries, all faced with the same laws of nature, yet each with unique features." A 2021 analysis proposes the term emerged to describe markets, economies, or countries that have graduated from emerging market status, but have not yet reached

3750-453: The children of someone with Down syndrome will also have the syndrome. The cause of the extra full or partial chromosome is still unknown. Most of the time, Down syndrome is caused by a random mistake in cell division during early development of the fetus, but not inherited, and there is no scientific research which shows that environmental factors or the parents' activities contribute to Down syndrome. The only factor that has been linked to

3825-447: The chromosomes in the mother, 8% from nonseparation in the father, and 3% after the egg and sperm have merged. Mosaic Down syndrome is diagnosed when there is a mixture of two types of cells: some cells have three copies of chromosome 21 but some cells have the typical two copies of chromosome 21. This type is the least common form of Down syndrome and accounts for only about 1% of all cases. Children with mosaic Down syndrome may have

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3900-528: The detection rate. None can be definitive; thus, if screening predicts a high possibility of Down syndrome, either amniocentesis or chorionic villus sampling is required to confirm the diagnosis. Prenatal ultrasound can be used to screen for Down syndrome. Findings that indicate increased chances when seen at 14 to 24 weeks of gestation include a small or no nasal bone, large ventricles , nuchal fold thickness , and an abnormal right subclavian artery , among others. The presence or absence of many markers

3975-466: The development of TAM on the preleukemic pathway. The condition affects 3–10% of babies with Down. While it often spontaneously resolves within three months of birth, it can cause serious blood, liver, or other complications. In about 10% of cases, TMD progresses to AMKL during the three months to five years following its resolution. People with Down syndrome have a lower risk of all major solid cancers, including those of lung, breast, and cervix, with

4050-464: The disease. Down syndrome regression disorder is a sudden regression with neuropsychiatric symptoms such as catatonia , possibly caused by an autoimmune disease. It primarily appears in teenagers and younger adults. Hearing and vision disorders occur in more than half of people with Down syndrome. Brushfield spots (small white or grayish/brown spots on the periphery of the iris ), upward slanting palpebral fissures (the opening between

4125-413: The first year of life and are partly due to poor eustachian tube function. Excessive ear wax can also cause hearing loss due to obstruction of the outer ear canal . Even a mild degree of hearing loss can have negative consequences for speech, language understanding, and academics. It is important to rule out hearing loss as a factor in social and cognitive deterioration. Age-related hearing loss of

4200-768: The gap tends to widen between people with Down syndrome and their same-age peers. Commonly, individuals with Down syndrome have better language understanding than ability to speak. Babbling typically emerges around 15 months on average. 10–45% of those with Down syndrome have either a stutter or rapid and irregular speech , making it difficult to understand them. After reaching 30 years of age, some may lose their ability to speak. They typically do fairly well with social skills. Behavior problems are not generally as great an issue as in other syndromes associated with intellectual disability. In children with Down syndrome, mental illness occurs in nearly 30% with autism occurring in 5–10%. People with Down syndrome experience

4275-457: The increased chance of having a baby with Down syndrome is advanced parental age. This is mostly associated with advanced maternal age but about 10 per cent of cases are associated with advanced paternal age . Down syndrome is caused by having three copies of the genes on chromosome 21 , rather than the usual two. The parents of the affected individual are typically genetically normal. Those who have one child with Down syndrome have about

4350-489: The increased prevalence of keratoconus. An association between glaucoma and Down syndrome is often cited. Glaucoma in children with Down syndrome is uncommon, with a prevalence of less than 1%. It is currently unclear if the prevalence of glaucoma in those with Down syndrome differs from that in the absence of Down syndrome. Estimates of prevalence of ocular findings in Down Syndrome vary widely depending on

4425-516: 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). As of 2024, there is no known cure for Down syndrome. Education and proper care have been shown to provide better quality of life . Some children with Down syndrome are educated in typical school classes, while others require more specialized education . Some individuals with Down syndrome graduate from high school , and

4500-458: The level equivalent to developed countries. Multinational corporations from these emerging markets present unique patterns of overseas expansion and knowledge acquisition from foreign countries. The UN HDI is a statistical measure that gauges an economy's level of human development. While there is a strong correlation between having a high HDI score and being a prosperous economy, the UN points out that

4575-424: The likelihood of developing acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) is higher in children with Down syndrome compared to those without Down syndrome. Myeloid leukemia typically precedes Down syndrome and is accompanied by a condition known as transient abnormal myelopoiesis (TAM), which generally disrupts the differentiation of megakaryocytes and erythrocytes. In Down syndrome, AMKL

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4650-445: The lower front teeth. While plaque and poor oral hygiene are contributing factors, the severity of these periodontal diseases cannot be explained solely by external factors. Research suggests that the severity is likely a result of a weakened immune system. The weakened immune system also contributes to increased incidence of yeast infections in the mouth (from Candida albicans ). People with Down syndrome also tend to have

4725-492: The lowest relative rates occurring in those aged 50 years or older. This low risk is thought to be due to an increase in the expression of tumor suppressor genes present on chromosome 21. One exception is testicular germ cell cancer which occurs at a higher rate in Down syndrome. Problems of the thyroid gland occur in 20–50% of individuals with Down syndrome. Low thyroid is the most common form, occurring in almost half of all individuals. Thyroid problems can be due to

4800-462: The lungs narrow and cause inadequate blood oxygenation. Some of the genetic contributions to pulmonary hypertension in individuals with Down Syndrome are abnormal lung development, endothelial dysfunction , and proinflammatory genes. Mitral valve problems become common as people age, even in those without heart problems at birth. Other problems that may occur include tetralogy of Fallot and patent ductus arteriosus . People with Down syndrome have

4875-603: The person's life. Down syndrome is the most common chromosomal abnormality , occurring in about 1 in 1,000 babies born worldwide, and one in 700 in the US. In 2015, there were 5.4 million people with Down syndrome globally, of whom 27,000 died, down from 43,000 deaths in 1990. The syndrome is named after British physician John Langdon Down , who fully described it in 1866. Some aspects were described earlier by French psychiatrist Jean-Étienne Dominique Esquirol in 1838 and French physician Édouard Séguin in 1844. The genetic cause

4950-658: The pulp chamber, has a high prevalence in people with DS. Males with Down syndrome usually do not father children, while females have lower rates of fertility relative to those who are unaffected. Fertility is estimated to be present in 30–50% of females. Menopause usually occurs at an earlier age. The poor fertility in males is thought to be due to problems with sperm development ; however, it may also be related to not being sexually active. As of 2006, three instances of males with Down syndrome fathering children and 26 cases of females having children have been reported. Without assisted reproductive technologies , around half of

5025-447: The risk of vision loss from amblyopia . Dot-like opacities in the cortex of the lens (cerulean cataract) are present in up to 50% of people with Down syndrome, but may be followed without treatment if they are not visually significant. Strabismus , nystagmus and nasolacrimal duct obstruction occur more frequently in children with Down syndrome. Screening for these diagnoses should begin within six months of birth. Strabismus

5100-437: The same features as other children with Down syndrome. However, they may have fewer characteristics of the condition due to the presence of some (or many) cells with a typical number of chromosomes. The extra chromosome 21 material may also occur due to a Robertsonian translocation in 2–4% of cases. In this translocation Down syndrome, the long arm of chromosome 21 is attached to another chromosome, often chromosome 14 . In

5175-434: The second trimester, often two or three tests are used in combination with two or three of: α-fetoprotein , unconjugated estriol, total hCG, and free βhCG detecting about 60–70% of cases. Testing of the mother's blood for fetal DNA is being studied and appears promising in the first trimester. The International Society for Prenatal Diagnosis considers it a reasonable screening option for those women whose pregnancies are at

5250-540: The study. Some prevalence estimates follow. Vision problems have been observed in 38–80% of cases. Brushfield spots are present in 38–85% of individuals. Between 20 and 50% have strabismus . Cataracts occur in 15%, and may be present at birth. Keratoconus may occur in as many as 21–30%. Hearing problems are found in 50–90% of children with Down syndrome. This is often the result of otitis media with effusion which occurs in 50–70% and chronic ear infections which occur in 40–60%. Ear infections often begin in

5325-541: The upper and lower lids) and epicanthal folds (folds of skin between the upper eyelid and the nose) are clinical signs at birth suggesting the diagnosis of Down syndrome especially in the Western World . None of these requires treatment. Visually significant congenital cataracts (clouding of the lens of the eye) occur more frequently with Down syndrome. Neonates with Down syndrome should be screened for cataract because early recognition and referral reduce

5400-504: The world's major donor countries that discusses issues surrounding development aid and poverty reduction in developing countries . The following OECD member countries are DAC members: 25 countries in Europe: two countries in the Americas: two countries in Asia: two countries in Oceania: According to the International Monetary Fund , 41 countries and territories are officially listed as "advanced economies", with

5475-603: The year 2022 are considered to be of "very high human development": annual growth (2010-2022) According to the United Nations Department of Economic and Social Affairs ' World Economic Situation and Prospects report, the following 37 countries are classified as "developed economies" as of January 2024: 31 countries in Europe: two countries in Northern America: four countries in Asia and

5550-536: Was born in 1978 with Down Syndrome. The parents soon discovered that the support and resources available to parents with Down syndrome children were very limited. Goodwin and Arden created the NDSS, which gained official nonprofit status in 1979. The National Down Syndrome Society envisions "a world in which all people with Down syndrome have the opportunity to enhance their quality of life, realize their life aspirations and become valued members of welcoming communities." NDSS focuses on four items of programming to enhance

5625-404: Was discovered in 1959. Those with Down syndrome nearly always have physical and intellectual disabilities. As adults, their mental abilities are typically similar to those of an 8- or 9-year-old. At the same time, their emotional and social awareness is very high. They can have poor immune function and generally reach developmental milestones at a later age. They have an increased risk of

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