what is the clinical course of down syndrome

What is Down syndrome?

Down syndrome is a genetic disorder caused when abnormal cell division results in an extra full or partial copy of chromosome 21. This extra genetic material causes the developmental changes and physical features of Down syndrome.

How is Down syndrome diagnosed and treated?

How Is Down Syndrome Diagnosed? There are two categories of tests for Down syndrome that can be performed before a baby is born: screening tests and diagnostic tests. Prenatal screens estimate the chance of the fetus having Down syndrome. These tests do not tell you for sure whether your fetus has Down syndrome; they only provide a probability.

What are the physical traits of Down syndrome?

A few of the common physical traits of Down syndrome are low muscle tone, small stature, an upward slant to the eyes, and a single deep crease across the center of the palm – although each person with Down syndrome is a unique individual and may possess these characteristics to different degrees, or not at all. How Common is Down Syndrome?

How are students with Down syndrome treated in the classroom?

Sometimes students with Down syndrome are included in specific courses, while in other situations students are fully included in the typical classroom for all subjects. Increasingly, individuals with Down syndrome graduate from high school with diplomas, and participate in postsecondary academic and college programs.

Why are children born with Down syndrome?

What is the genetic variation that causes Down syndrome?

What is Down syndrome?

What is the XY chromosome?

Why do women have a greater risk of having a baby with Down syndrome?

Why are Down syndrome patients at greater risk for obstructive sleep apnea?

How long can a person with Down syndrome live?

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What is the course of Down syndrome?

Down syndrome results when abnormal cell division involving chromosome 21 occurs. These cell division abnormalities result in an extra partial or full chromosome 21. This extra genetic material is responsible for the characteristic features and developmental problems of Down syndrome.

What is the clinical feature of Down syndrome?

People with Down syndrome usually have an IQ (a measure of intelligence) in the mildly-to-moderately low range and are slower to speak than other children. Some common physical features of Down syndrome include: A flattened face, especially the bridge of the nose. Almond-shaped eyes that slant up.

Is Down syndrome a clinical disorder?

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 physical growth delays, mild to moderate intellectual disability, and characteristic facial features.

What is the clinical name for Down syndrome?

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.

What are the clinical characteristics consistent with a diagnosis of trisomy 21?

On physical examination, patients with trisomy 21 have characteristic craniofacial findings, such as the following: Flat occiput and a flattened facial appearance. Small brachycephalic head. Epicanthal folds.

What are the signs of Down syndrome in a newborn?

At birth, babies with Down syndrome usually have certain characteristic signs, including:flat facial features.small head and ears.short neck.bulging tongue.eyes that slant upward.atypically shaped ears.poor muscle tone.

When is Down syndrome diagnosed?

Diagnostic tests that can identify Down syndrome include: Chorionic villus sampling (CVS). In CVS, cells are taken from the placenta and used to analyze the fetal chromosomes. This test is typically performed in the first trimester, between 10 and 13 weeks of pregnancy.

What causes Down syndrome in a baby?

Down Syndrome Causes and Risk Factors One chromosome in each pair comes from your mother and the other comes from your father. But with Down syndrome, something goes wrong and you get an extra copy of chromosome 21. That means you have three copies instead of two, which leads to the symptoms of Down syndrome.

Is Down syndrome a mental or physical disability?

Down syndrome is the most common genetic cause of intellectual disability, affecting approximately 1 in every 700 children. It is named for John Langdon Down, the British physician who first recognized the traits of Down syndrome in 1866.

What are the 3 types of Down syndrome?

There are three types of Down syndrome: trisomy 21 (nondisjunction), translocation and mosaicism. Trisomy 21 (nondisjunction) accounts for 95% of known cases of Down syndrome.

Why is it called Down syndrome?

Down syndrome is named for the English physician John Langdon Down, who characterized the condition, but did not have it. An “apostrophe s” connotes ownership or possession.

What are the genetic causes of Down syndrome?

Affected people have two normal copies of chromosome 21 plus extra material from chromosome 21 attached to another chromosome, resulting in three copies of genetic material from chromosome 21. Affected individuals with this genetic change are said to have translocation Down syndrome.

Down Syndrome: Causes, Symptoms, Diagnosis, & Treatment

People with Down syndrome have an extra chromosome that impacts how a person looks and their ability to think, learn, and reason. Find out the type, causes, and kinds of effects it can have.

What are common treatments for Down syndrome? | NICHD - Eunice Kennedy ...

There is no single, standard treatment for Down syndrome. Treatments are based on each individual's physical and intellectual needs as well as his or her personal strengths and limitations. 1 People with Down syndrome can receive proper care while living at home and in the community. A child with Down syndrome likely will receive care from a team of health professionals, including, but not ...

What causes Down syndrome? | NICHD - Eunice Kennedy Shriver National ...

Down syndrome is caused by a random error in cell division that results in the presence of an extra copy of chromosome 21. The type of error is called nondisjunction ...

What is Down syndrome?

Down syndrome describes a set of cognitive and physical symptoms that result from an extra copy or part of a copy of chromosome 21. Chromosomes carry the genes that tell the body to develop in certain ways and to perform certain functions. Most cells of the human body contain 23 pairs of chromosomes—one set of chromosomes from each parent— ...

What is the degree of intellectual disability in people with Down syndrome?

1. The degree of intellectual disability in people with Down syndrome varies but is usually mild to moderate.

Why do they take a blood sample of a baby with Down syndrome?

But because individuals with Down syndrome may not have these symptoms, and because many of these symptoms are common in the general population, the health care provider will take a sample of the baby's blood to confirm the diagnosis. The blood sample is analyzed to determine the number of the baby's chromosomes. 11.

How many chromosomes are there in Down syndrome?

People with Down syndrome have either a full or partial extra copy of chromosome 21, for a total of 47 chromosomes. (The syndrome is sometimes called 47,XX,+21 or 47,XY,+21 to indicate the extra chromosome 21.) The extra chromosome disrupts the normal course of development and results in the physical features and intellectual ...

How many types of chromosomal changes can lead to Down syndrome?

Research shows that three types of chromosomal changes can lead to Down syndrome.

When does mosaic trisomy 21 occur?

It can also occur early in development when some cells lose an extra chromosome 21 that was present at conception. The symptoms of someone with mosaic trisomy 21 may vary from those of someone with complete trisomy 21 or translocation trisomy 21, depending on how many cells have the extra chromosome. 1, 2.

Which chromosome is most likely to cause mild to moderate intellectual disability?

Down syndrome is the most frequent chromosomal cause of mild to moderate intellectual disability, and it occurs in all ethnic and economic groups. 2

What are the physical characteristics of Down syndrome?

Some common physical features of Down syndrome include: A flattened face, especially the bridge of the nose. Almond-shaped eyes that slant up. A short neck.

Why can't people tell the difference between the two types of Down syndrome?

People often can’t tell the difference between each type without looking at the chromosomes because the physical features and behaviors are similar. Trisomy 21: About 95% of people with Down syndrome have Trisomy 21. 2 With this type of Down syndrome, each cell in the body has 3 separate copies of chromosome 21 instead of the usual 2 copies.

How Many Babies are Born with Down Syndrome?

Down syndrome remains the most common chromosomal condition diagnosed in the United States. Each year, about 6,000 babies born in the United States have Down syndrome. This means that Down syndrome occurs in about 1 in every 700 babies. 1

How many copies of chromosome 21 are there in Down syndrome?

For children with mosaic Down syndrome, some of their cells have 3 copies of chromosome 21, but other cells have the typical two copies of chromosome 21. Children with mosaic Down syndrome may have the same features as other children with Down syndrome. However, they may have fewer features of the condition due to the presence of some (or many) ...

What is the extra chromosome in Down syndrome?

Babies with Down syndrome have an extra copy of one of these chromosomes, chromosome 21. A medical term for having an extra copy of a chromosome is ‘trisomy.’. Down syndrome is also referred to as Trisomy 21. This extra copy changes how the baby’s body and brain develop, which can cause both mental and physical challenges for the baby.

What is the percentage of people with Down syndrome who are translocated?

Translocation Down syndrome: This type accounts for a small percentage of people with Down syndrome (about 3%). 2 This occurs when an extra part or a whole extra chromosome 21 is present, but it is attached or “trans-located” to a different chromosome rather than being a separate chromosome 21.

Why is there an extra chromosome 21?

Causes and Risk Factors. The extra chromosome 21 leads to the physical features and developmental challenges that can occur among people with Down syndrome. Researchers know that Down syndrome is caused by an extra chromosome, but no one knows for sure why Down syndrome occurs or how many different factors play a role.

What Is Down Syndrome?

This condition is called Down syndrome, and it is the most common chromosomal abnormality, one that leads to severe intellectual disabilities and health problems. One in about 700 to 1000 children will be born with this condition. Most children with this problem are born to mothers under the age of 35, but older mothers have an increased risk of having a child with Down syndrome. For example, the chances that a woman aged 45 will have a child with Down syndrome are 20 times greater than normal.

What part of the brain is responsible for emotion?

One thing that has been noted is that children with Down syndrome seem to have difficulties in tasks involving many areas of the brain, including the prefrontal cortex, an area of the brain responsible for behavior, attention, decision making, emotion, and complex thought. Since it's so important in so many areas of life, it's no surprise that the prefrontal cortex is at the very front of your brain just like someone of equal importance would want to be at the front of a line.

How many chromosomes do you get from your mother?

However, women aren't solely to blame here by any means. The reason this genetic condition occurs is as follows. When a baby is conceived, it receives 23 chromosomes from its mother and 23 chromosomes from its father for a total of 46 chromosomes. The way to remember that is to think about the fact that the perfect number of chromosomes you can get from either your mother or father is 23. That would be considered to be a slam dunk, exactly what you want. And who's the best NBA player in history? Michael Jordan, number 23 for the Chicago Bulls.

What part of the brain is responsible for behavior, attention, decision making, emotion, and complex thought?

One thing that has been noted is that children with Down syndrome seem to have difficulties in tasks involving many areas of the brain, including the prefrontal cortex, an area of the brain responsible for behavior, attention, decision making, emotion, and complex thought.

What are the symptoms of extra chromosomes?

The effect the extra chromosome may have on the prefrontal cortex and other areas of the brain may explain some of the signs and symptoms associated with this condition, such as intellectual disabilities, late onset of motor activities (such as walking), and seizures.

Why do we have extra chromosomes in our eggs?

One thing we know for sure is that chromosome 21 is the chromosome whose additional copy in the egg or sperm causes a child to develop Down syndrome.

What is the most common chromosomal abnormality?

Lesson Summary. In this lesson, we learned about a condition that is called Down syndrome, which is the most common chromosomal abnormality, one that leads to severe intellectual disabilities and health problems.

What is Down Syndrome?

Typically, the nucleus of each cell contains 23 pairs of chromosomes, half of which are inherited from each parent. Down syndrome occurs when an individual has a full or partial extra copy of chromosome 21.

What are the physical characteristics of Down syndrome?

A few of the common physical traits of Down syndrome are low muscle tone, small stature, an upward slant to the eyes, and a single deep crease across the center of the palm – although each person with Down syndrome is a unique individual and may possess these characteristics to different degrees, or not at all.

How Common is Down Syndrome?

According to the Centers for Disease Control and Prevention, approximately one in every 700 babies in the United States is born with Down syndrome, making Down syndrome the most common chromosomal condition. About 6,000 babies with Down syndrome are born in the United States each year.

When Was Down Syndrome Discovered?

It was this scholarly work, published in 1866, that earned Down the recognition as the “father” of the syndrome. Although other people had previously recognized the characteristics of the syndrome, it was Down who described the condition as a distinct and separate entity.

What is the Likelihood of Having a Child with Down Syndrome?

Down syndrome occurs in people of all races and economic levels, though older women have an increased chance of having a child with Down syndrome. A 35 year old woman has about a one in 350 chance of conceiving a child with Down syndrome, and this chance increases gradually to 1 in 100 by age 40. At age 45 the incidence becomes approximately 1 in 30. The age of the mother does not seem to be linked to the risk of translocation.

Does Down Syndrome Run in Families?

All 3 types of Down syndrome are genetic conditions (relating to the genes), but only 1% of all cases of Down syndrome have a hereditary component (passed from parent to child through the genes). Heredity is not a factor in trisomy 21 (nondisjunction) and mosaicism. However, in one-third of cases of Down syndrome resulting from translocation there is a hereditary component – accounting for about 1% of all cases of Down syndrome.

What Impact Does Down Syndrome Have on Society?

Individuals with Down syndrome are becoming increasingly integrated into society and community organizations, such as school, health care systems, work forces, and social and recreational activities. Individuals with Down syndrome possess varying degrees of cognitive delays, from very mild to severe. Most people with Down syndrome have cognitive delays that are mild to moderate.

What are the best treatments for DSDD?

Several therapies have revealed some clinical benefit in patients with DSDD. Symptomatically, antipsychotics (eg, risperidone), SSRIs (eg, fluoxetine and sertraline), and anticholinergic drugs (eg, donepezil and rivastigmine) have been used to address many of the neuropsychiatric disturbances observed in DSDD. 4 In 3 recent studies, 25% of patients showed a response to SSRIs, which seem to improve mood symptoms, motor symptoms, and sleep disturbance. 12, 31 Tamasaki et al 31 reported a case study of a 14-year-old boy with DSDD symptoms who was treated with donepezil, which led to a complete psychosocial recovery; however, the efficacy of cholinergic medications for cognitive impairment in individuals with DS is debatable, and they are not US Food and Drug Administration approved for children and adolescents. 32, 33 Another therapeutic option for persons with DSDD is antipsychotic treatment. Across 4 studies, 70% of patients experienced at least some improvement in motor symptoms, sleep disturbance, and catatonia with antipsychotic therapy. 2, 12, 13

What are the triggers of regression in DSDD?

An alternative hypothesis proposes that psychological stress may act as a trigger of regression in DSDD ( Fig 1 ). In their studies, Stein et al 22 and Mircher et al 5 postulated that such behavioral changes may be a way for persons with DS to express distress in the context of their developmental delays. Across 3 studies, 86% of persons with DSDD ( n = 30 of 35) reported identifiable life stressors preceding the onset of symptoms. In the largest study of 30 patients, Mircher et al 5 described a new school environment as the most common life stressor preceding a diagnosis of DSDD (51%). 11, 22 Other common stressors were awareness of disability triggered by the wedding or departure of a sibling (23%), assault (17%), illness of a close one (13%), and overstimulation (10%). 5 Although notable, many children with DS experience similar stressful triggers and do not have similar neuropsychiatric changes, rendering stress-related triggers an incomplete explanation. Stein et al 22 also reported on the role of environmental changes as potential triggers for regression in DSDD. In their case study, the authors reported that a patient with DS developed reactive depression after moving to a new city and changing schools. 23 The authors postulated that the patient dealt with distress through complex behavioral and adaptive changes because she failed to express her distress with the usual verbal channels. 22 This description would exist on the spectrum of an acute stress reaction as opposed to a primary psychiatric disease and thus may explain the recovery noted in patients over time. Mircher et al 5 put forth a hypothesis that explains the susceptibility in terms of widespread dysregulation of serotoninergic and cholinergic circuits. If this were the case, DSDD may be amenable to treatment with selective serotonin reuptake inhibitors (SSRIs), which have only been explored in a few studies thus far. 24, 25

What causes DSDD?

Whereas the etiology of DSDD is not fully understood, 2 possible causes that have been proposed are immune dysregulation and psychological stress triggering neuropsychiatric presentations (analogous to Rollin’s 6 original report). The demographic profile of DSDD includes a postpubertal onset and an elevated female/male patient ratio of 2:1 in the 2 largest studies to date. 4, 5 This finding has raised the suspicion that inflammation may play a role in the etiology of DSDD because this demographic is mirrored in other inflammatory disorders such as multiple sclerosis and autoimmune encephalitis. 4, 5, 13, 15 Additionally, recent research has revealed the presence of other autoantibodies, such as antinuclear antibodies, anti-microsomal antibodies, striational antibodies, thyroperoxidase antibodies, and anti-tissue transglutaminase antibodies, which have elevated levels in some individuals with DSDD. 11 These findings may be understood as a consequence of DS, which is generally associated with high serum levels of proinflammatory cytokines, high rates of complement protein consumption, and various other forms of immune dysregulation. 16 As the autoimmune etiology of several psychiatric syndromes becomes increasingly accepted, researchers speculate that some cases of DSDD may be driven by autoimmunity. 17, 18

What are the symptoms of DSDD?

In 3 large studies, up to 87% of patients with DSDD were diagnosed with language regression, with symptoms ranging in severity from dysfluency to mutism . 5, 11, 12 Among patients in whom severity of language regression was quantified, 38% had partial language regression and 52% had mutism. 5, 11, 12 Mood symptoms are also reported and include depression (42%), social withdrawal (34%), and anxiety (16%). 5, 12, 13 In recent studies, catatonia was observed in 47% of cases labeled as DSDD, which is higher than rates originally reported by Rollin 6 (38%). 5, 11, 12 New-onset insomnia was also described in 43% of cases. 4, 5, 7, 11, 12 Pooled estimates from 4 studies revealed a 14% rate of psychotic symptoms, including delusions and hallucinations, in persons with DSDD. 4, 5, 11, 12 Aggressive behavior was reported in 42% of patients. 2, 5, 11, 13 As was highlighted by Mircher et al, 5 aggression in persons with DSDD may be directed toward self (auto-aggression) or others (hetero-aggression). A minority of patients with DSDD (12%) also had anorexia as part of their clinical presentation. 11, 12

What is DSDD in children?

Down syndrome disintegrative disorder (DSDD), a developmental regression in children with Down syndrome (DS), is a clinical entity that is characterized by a loss of previously acquired adaptive, cognitive, and social functioning in persons with DS usually in adolescence to early adulthood. Initially reported in 1946 as “catatonic psychosis,” there has been an increasing interest among the DS community, primary care, and subspecialty providers in this clinical area over the past decade. This condition has a subacute onset and can include symptoms of mood lability, decreased participation in activities of daily living, new-onset insomnia, social withdrawal, autistic-like regression, mutism, and catatonia. The acute phase is followed by a chronic phase in which baseline functioning may not return. No strict criteria or definitive testing is currently available to diagnose DSDD, although a comprehensive psychosocial and medical evaluation is warranted for individuals presenting with such symptoms. The etiology of DSDD is unknown, but in several hypotheses for regression in this population, psychological stress, primary psychiatric disease, and autoimmunity are proposed as potential causes of DSDD. Both psychiatric therapy and immunotherapies have been described as DSDD treatments, with both revealing potential benefit in limited cohorts. In this article, we review the current data regarding clinical phenotypes, differential diagnosis, neurodiagnostic workup, and potential therapeutic options for this unique, most disturbing, and infrequently reported disorder.

What is the most common cause of intellectual disability?

Down syndrome (DS) is the most common cause of intellectual disability worldwide and occurs in ∼1 in 800 live births; it is most frequently caused by trisomy of chromosome 21 due to nondisjunction or translocation events. 1 – 3 In recent years, multiple centers have reported a specific pattern of developmental regression in individuals with DS, wherein patients lose language, behavioral, and cognitive skills that they previously acquired. 4, 5 This condition has been more recently referred to as Down syndrome disintegrative disorder (DSDD). DSDD can be severe, with implications on both quality of life and the autonomy of persons with DS. 4 It is, therefore, key for all providers to be aware of DSDD to evaluate and potentially treat this condition. The etiology, pathophysiology, and therapeutic options for DSDD are currently unclear, although clinical data are rapidly emerging. Our focus for this review is to summarize the current knowledge of clinical features, potential etiologies, neurodiagnostic workup, and therapeutic options and to identify future areas of focus and research in this field.

What is DSDD in psychology?

Because there are no diagnostic criteria available, DSDD is best described as a clinical syndrome that should be considered in adolescents and young adults with DS and subacute-onset behavioral changes. 13 It is also key to appreciate that persons with DS may experience adaptive, social, or cognitive regression for reasons other than DSDD, making a complete workup critical in the assessment of these patients (see Evaluation and Differential Diagnosis). Compared with the typical onset of autistic regression in persons with DS, DSDD takes place when patients are older, typically between the first and third decade. 4, 13 The acute regression appears to last for ∼6 months and is followed by a chronic phase in which previous skills may not be completely recovered ( Table 3 ). In 2 studies, it has been reported that 58% of persons with DSDD experience a partial or total recovery. Only 7.5% of patients experience additional worsening, whereas 35% of patients stabilize. 4, 5 However, in patients with stabilizing DSDD, a complete recovery to the premorbid baseline condition appears to be infrequent. 2, 4

How do people with Down syndrome learn?

This finding has been demonstrated across a number of areas of development including the acquisition of language, motor skills and literacy . This suggests that teaching will be more effective when information is presented with the support of pictures, gestures or objects.

How does Down syndrome affect social development?

Social development. The social functioning of babies and children with Down syndrome is relatively less delayed than other areas of development. Babies with Down syndrome look at faces and smile only a week or two later than other children and they are usually sociable infants. Infants with Down syndrome enjoy communicating and make good use ...

How does Down syndrome affect motor skills?

Motor development. Motor skills develop at a slower rate for children with Down syndrome than for those without. These delays in motor development reduce infants' opportunities for exploring and learning about the world around them and therefore further affect cognitive development. Poor oral motor control may impact the development ...

How many years behind reading skills for Down syndrome?

Number skills. Most children with Down syndrome struggle with basic number skills and their number skills are typically some 2 years behind their reading skills. There is a need for more research into the reasons for this. Currently, the best available advice is to draw on what is known about the children's learning strengths ...

Why is visual support important for Down syndrome?

This information has led to educators stressing the importance of using visual supports including pictures, signs and print when teaching children with Down syndrome as this approach makes full use of their stronger visual memory skills.

Why is reading important for children with Down syndrome?

Reading makes an important contribution to vocabulary and language development for all children and this may be a particular benefit for children with Down syndrome, given their specific language delays.

Can Down syndrome affect visual memory?

The ability of children with Down syndrome to hold and process verbal information is not as good as their ability to hold and process visual information. These verbal short-term memory problems make it more difficult to learn new words and sentences. They also make it more difficult to process spoken language and this can adversely affect ...

How do people with Down syndrome learn?

This finding has been demonstrated across a number of areas of development including the acquisition of language, motor skills and literacy . This suggests that teaching will be more effective when information is presented with the support of pictures, gestures or objects.

How does Down syndrome affect social development?

Social development. The social functioning of babies and children with Down syndrome is relatively less delayed than other areas of development. Babies with Down syndrome look at faces and smile only a week or two later than other children and they are usually sociable infants. Infants with Down syndrome enjoy communicating and make good use ...

How does Down syndrome affect motor skills?

Motor development. Motor skills develop at a slower rate for children with Down syndrome than for those without. These delays in motor development reduce infants' opportunities for exploring and learning about the world around them and therefore further affect cognitive development. Poor oral motor control may impact the development ...

How many years behind reading skills for Down syndrome?

Number skills. Most children with Down syndrome struggle with basic number skills and their number skills are typically some 2 years behind their reading skills. There is a need for more research into the reasons for this. Currently, the best available advice is to draw on what is known about the children's learning strengths ...

Why is visual support important for Down syndrome?

This information has led to educators stressing the importance of using visual supports including pictures, signs and print when teaching children with Down syndrome as this approach makes full use of their stronger visual memory skills.

Why is reading important for children with Down syndrome?

Reading makes an important contribution to vocabulary and language development for all children and this may be a particular benefit for children with Down syndrome, given their specific language delays.

Can Down syndrome affect visual memory?

The ability of children with Down syndrome to hold and process verbal information is not as good as their ability to hold and process visual information. These verbal short-term memory problems make it more difficult to learn new words and sentences. They also make it more difficult to process spoken language and this can adversely affect ...

Why are children born with Down syndrome?

However, most children with Down syndrome are born to women under age 35 because younger women have far more babies. Being carriers of the genetic translocation for Down syndrome. Both men and women can pass the genetic translocation for Down syndrome on to their children. Having had one child with Down syndrome.

What is the genetic variation that causes Down syndrome?

Any one of three genetic variations can cause Down syndrome: Trisomy 21. About 95 percent of the time, Down syndrome is caused by trisomy 21 — the person has three copies of chromosome 21, instead of the usual two copies, in all cells. This is caused by abnormal cell division during the development of the sperm cell or the egg cell.

What is Down syndrome?

Down syndrome is a genetic disorder caused when abnormal cell division results in an extra full or partial copy of chromosome 21. This extra genetic material causes the developmental changes and physical features of Down syndrome. Down syndrome varies in severity among individuals, causing lifelong intellectual disability and developmental delays. ...

What is the XY chromosome?

This XY chromosome pair includes the X chromosome from the egg and the Y chromosome from the sperm. In Down syndrome, there is an additional copy of chromosome 21, resulting in three copies instead of the normal two copies. Down syndrome is a genetic disorder caused when abnormal cell division results in an extra full or partial copy ...

Why do women have a greater risk of having a baby with Down syndrome?

A woman's chances of giving birth to a child with Down syndrome increase with age because older eggs have a greater risk of improper chromosome division.

Why are Down syndrome patients at greater risk for obstructive sleep apnea?

Sleep apnea. Because of soft tissue and skeletal changes that lead to the obstruction of their airways, children and adults with Down syndrome are at greater risk of obstructive sleep apnea.

How long can a person with Down syndrome live?

Life spans have increased dramatically for people with Down syndrome. Today, someone with Down syndrome can expect to live more than 60 years, depending on the severity of health problems.

What Is Down Syndrome?

How Many Babies Are Born with Down Syndrome?

Types of Down Syndrome

Causes and Risk Factors

Diagnosis

• Each person with Down syndrome is an individual — intellectual and developmental problems may be mild, moderate or severe. Some people are healthy while others have significant health problems such as serious heart defects. Children and adults with Down syndrome have distinct …

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Screening Tests

Diagnostic Tests

Other Health Problems

Treatments

Other Resources

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What Is Down Syndrome?

Why Does Down Syndrome occur?

Clinical Signs, Symptoms, and Diagnostics