Down syndrome

Down syndrome, also known as trisomy 21, is a genetic condition caused by the presence of all or part of a third copy of chromosome 21. It is one of the most common genetic conditions, affecting approximately 1 in every 700 babies born in the United States. The condition is characterized by various physical and intellectual disabilities, as well as an increased risk of certain medical conditions.

Individuals with Down syndrome typically have distinctive facial features, such as a flat face, upward slanting eyes, and a small mouth and ears. They may also have a shorter stature, decreased muscle tone, and an increased susceptibility to certain diseases.

While the exact causes of Down syndrome are not fully understood, most cases are not inherited and occur as a result of random events during the division of the cells in the reproductive process. However, in a small percentage of cases, Down syndrome is inherited from one of the parents who carries a chromosomal rearrangement.

There are several resources available for individuals and families affected by Down syndrome. Organizations like the Down Syndrome Research and Treatment Foundation and the National Down Syndrome Society provide support, education, and advocacy for individuals with Down syndrome and their families. Additionally, there are numerous scientific and clinical studies available on resources like PubMed, ClinicalTrials.gov, and OMIM, which provide additional information and references for further learning about this condition.

Frequency

Down syndrome, also known as trisomy 21, is a genetic condition caused by the presence of an extra copy of chromosome 21. It is the most common chromosomal disorder, affecting approximately 1 in every 700 births worldwide.

The frequency of Down syndrome varies depending on factors such as maternal age and other genetic factors. It is more commonly observed in older mothers. The likelihood of having a child with Down syndrome increases with advancing maternal age.

Research studies have shown that the probability of having a baby with Down syndrome is as follows:

• At age 20: 1 in 1,500
• At age 30: 1 in 900
• At age 35: 1 in 350
• At age 40: 1 in 100

It is important to note that these figures are just estimates and the actual risk may vary for individual cases.

The characteristic features of Down syndrome include intellectual disability, developmental delays, and certain physical characteristics such as a flat facial profile, small head, slanted eyes, and a small mouth. However, individuals with Down syndrome may also face other health issues such as heart defects, gastrointestinal problems, and thyroid dysfunction.

While Down syndrome is most commonly caused by trisomy 21, there are other forms of the condition as well, including translocation Down syndrome and mosaic Down syndrome.

Translocation Down syndrome occurs when a part of chromosome 21 gets attached to another chromosome during cell division. This can be inherited from a parent or can happen randomly. Mosaic Down syndrome occurs when there is a mixture of cells with the usual two copies of chromosome 21 and those with three copies. This form of Down syndrome is considered to be less severe.

Studies and research continue to provide valuable information about Down syndrome. Resources such as the Online Mendelian Inheritance in Man (OMIM) catalog and PubMed offer a wealth of articles, studies, and clinical trials related to Down syndrome research and advocacy. Some notable researchers in the field include Dr. William Capone and Dr. Michael Roizen.

It is recommended that individuals with Down syndrome receive regular medical care and screening for associated conditions. Genetic testing can be done to confirm the diagnosis and provide additional information about the specific genes and chromosome structures involved.

In conclusion, Down syndrome is a relatively common genetic condition characterized by the presence of an extra copy of chromosome 21. The frequency of Down syndrome increases with maternal age, and individuals with Down syndrome may have a range of associated health conditions. Ongoing research and advocacy efforts provide valuable resources and information for individuals with Down syndrome and their families.

Causes

Down syndrome, also known as trisomy 21, is caused by the presence of an extra copy of chromosome 21. This additional genetic material alters the course of development and causes the characteristic features and disabilities associated with the syndrome.

Most cases of Down syndrome occur randomly, without any known or preventable cause. This is called “sporadic” occurrence. However, in some cases, Down syndrome can be inherited from a parent who carries the genetic abnormality.

The extra copy of chromosome 21 can originate from either the mother or the father. The risk of having a child with Down syndrome increases with the mother’s age, especially after the age of 35. However, due to higher birth rates in younger women, the majority of children with Down syndrome are born to women under the age of 35.

In addition to the extra chromosome 21, individuals with Down syndrome may also have other genetic variations or conditions. These additional conditions can contribute to the wide range of features and health issues that can vary from person to person.

There are rare cases of Down syndrome caused by other types of genetic abnormalities, such as translocation or mosaicism. Translocation occurs when a piece of chromosome 21 attaches to another chromosome, while mosaicism involves the presence of some cells with an extra copy of chromosome 21 and others with the typical two copies.

Overall, Down syndrome is associated with a higher risk of certain medical conditions, including heart defects, intellectual disabilities, and thyroid disorders. The specific risk and frequency of these conditions vary among individuals with Down syndrome.

To learn more about the causes of Down syndrome and related conditions, additional information can be found in scientific articles and resources available from medical databases such as PubMed, clinical trial registries like ClinicalTrials.gov, and catalogs like OMIM (Online Mendelian Inheritance in Man).

Learn more about the chromosome associated with Down syndrome

Down syndrome is a condition that is caused by the presence of an extra copy of chromosome 21. This additional genetic material affects the normal development of the body and brain, leading to various physical and intellectual challenges. Individuals with Down syndrome often have characteristic facial features, intellectual disability, and may also experience other medical issues such as heart defects and thyroid gland problems.

Chromosome 21 is one of the 23 pairs of chromosomes in humans. It contains hundreds of genes, and having an extra copy of this chromosome means there is an additional set of genes present. This extra genetic material disrupts the normal development processes, causing the features and characteristics associated with Down syndrome.

The presence of an extra copy of chromosome 21 is usually not inherited. It occurs randomly during the formation of sperm or egg cells in one of the parents. This abnormality, known as trisomy 21, is the most common form of Down syndrome and occurs in about 95% of cases. Other rarer forms of Down syndrome include translocation Down syndrome and mosaic Down syndrome.

Scientific research has provided significant support for the understanding of the causes and effects of Down syndrome. The Genetic Testing Registry, a resource provided by the National Center for Biotechnology Information, offers a catalog of genetic tests for various conditions, including Down syndrome. Additionally, the National Library of Medicine’s PubMed database contains numerous scientific studies and references related to Down syndrome.

Genetic testing for Down syndrome can be done during pregnancy, either through non-invasive prenatal testing (NIPT) or invasive procedures such as chorionic villus sampling (CVS) or amniocentesis. These tests can detect the presence of an extra copy of chromosome 21 in the fetus.

It is important to note that having Down syndrome does not define an individual’s abilities or potential. With appropriate support and resources, individuals with Down syndrome can lead fulfilling and independent lives. Research on Down syndrome continues to provide valuable information and improve the understanding and care for individuals with this condition.

References:

1. Roizen, N. J. (2021). Down syndrome: prenatal risk assessment and diagnosis. UpToDate. Retrieved from https://www.uptodate.com/contents/down-syndrome-prenatal-risk-assessment-and-diagnosis.

2. National Down Syndrome Society. (n.d.). What Is Down Syndrome? Retrieved from https://www.ndss.org/about-down-syndrome/down-syndrome/.

3. National Human Genome Research Institute. (2017). Learning About Down Syndrome. Retrieved from https://www.genome.gov/Genetic-Disorders/Down-Syndrome.

Inheritance

Down syndrome is a genetic condition caused by the presence of an extra copy of chromosome 21 in a person’s cells. This extra genetic material leads to various developmental and physical characteristics associated with the syndrome.

The inheritance of Down syndrome is usually not passed down from parents to children. It occurs as a random event during the formation of reproductive cells (eggs and sperm) in one of the parents. In most cases, the extra chromosome is present in the egg before fertilization. This is known as trisomy 21, where there are three copies of chromosome 21 instead of the usual two.

Although the exact cause of the extra chromosome in Down syndrome is still unknown, scientists believe that the most common form, trisomy 21, occurs sporadically and is not related to anything the parents did or did not do.

Studies have shown that the incidence of Down syndrome increases with maternal age. However, the majority of babies with Down syndrome are born to mothers under the age of 35, as younger women have more children. This is due to the fact that younger women have a higher risk of having a baby with Down syndrome than older women, but older women have a higher risk of having a baby with Down syndrome simply because they have more babies.

There are two other rare forms of Down syndrome that are associated with genetic conditions. One is called translocation Down syndrome, which occurs when a piece of chromosome 21 attaches to another chromosome before or at the time of conception. The other is called mosaic Down syndrome, which occurs when there is a mixture of cells with the normal number of chromosomes and cells with an extra copy of chromosome 21.

In addition to the characteristic facial features and intellectual disability associated with Down syndrome, individuals with the condition are also at increased risk for certain medical conditions and diseases. These can include heart defects, digestive problems, hearing loss, thyroid conditions, and more. Regular medical check-ups, screenings, and support from healthcare professionals are important for managing these associated conditions.

Furthermore, there are numerous resources available for individuals with Down syndrome and their families. Advocacy organizations, such as the Down Syndrome Research and Treatment Foundation, provide information, support, and additional resources for those affected by the condition. Scientific articles, research studies, and clinical trials can be found through databases such as PubMed, OMIM, and ClinicalTrials.gov. These resources offer more information about the genetic causes, inheritance patterns, and potential treatments for Down syndrome and related conditions.

Other Names for This Condition

Down syndrome is a genetic condition caused by the presence of an extra copy of chromosome 21. This condition is also known by various other names:

• Trisomy 21 (the most common form of Down syndrome, where there are three copies of chromosome 21 instead of the usual two)
• Down’s syndrome (named after John Langdon Down, the British physician who first described the condition in 1866)
• Down’s
• Trisomy G (referring to the extra genetic material caused by the additional chromosome)
• DS

Individuals with Down syndrome often have distinctive facial features, such as almond-shaped eyes, a flat nasal bridge, and a protruding tongue. Additionally, they may have certain other medical conditions, some of which are more common in patients with Down syndrome:

• Heart defects
• Hearing loss
• Thyroid problems
• Intestinal abnormalities
• Vision problems
• Skeletal issues
• Immune system disorders

Though Down syndrome cannot be cured, early intervention and support can greatly improve the quality of life for individuals with this condition. Genetic testing is available to diagnose Down syndrome prenatally or after birth. Research and studies are ongoing to learn more about the genes and characteristics associated with Down syndrome.

If you would like to learn more about Down syndrome, here are some resources you may find helpful:

• National Down Syndrome Society (NDSS) – Provides information and support about Down syndrome, advocacy, and resources for individuals with Down syndrome and their families. Visit their website at https://www.ndss.org/.
• Down Syndrome Association (DSA) – Offers support, education, and resources for individuals with Down syndrome and their families. Visit their website at https://www.downsyn.com/.
• ClinicalTrials.gov – A database of privately and publicly funded clinical studies conducted around the world. Information on ongoing and completed clinical trials related to Down syndrome can be found at https://clinicaltrials.gov/.
• PubMed – A database of scientific articles in the field of medicine. Search for more information about Down syndrome at https://pubmed.ncbi.nlm.nih.gov/.
• Dr. Brian G. Skotko and Dr. Susan Levine – Dr. Skotko and Dr. Levine have conducted research and published numerous articles on Down syndrome. Their work can be found at https://www.downsyndromepregnancy.org/.
• The Down Syndrome Center at Children’s Hospital of Pittsburgh of UPMC – The center provides comprehensive care for individuals with Down syndrome and their families. Learn more about their services at https://www.chp.edu/our-services/down-syndrome.

It is important to note that individuals with Down syndrome may have an increased risk of developing certain diseases and conditions. However, it is also important to remember that each person is unique and not all individuals with Down syndrome will experience the same health issues.

For more detailed and accurate scientific information, please refer to the resources mentioned above and consult with medical professionals specialized in Down syndrome.

Additional Information Resources

Having a child with Down syndrome can present unique challenges and considerations. To help parents and caregivers navigate these challenges, the following resources provide additional information on various aspects of Down syndrome:

• Down Syndrome Division of the National Association for Down Syndrome (NADS) – The NADS provides support and resources for individuals with Down syndrome and their families. Their website offers a comprehensive catalog of information, research articles, and other publications related to Down syndrome.

• The Down Syndrome Clinic and Research Center at Children’s Hospital of Pittsburgh – This center provides clinical services for individuals with Down syndrome and conducts research studies to learn more about the genetic condition. Their website offers a wide range of resources, including information on testing, genetic counseling, and facial characteristic evaluation.

• National Institutes of Health’s Office of Rare Diseases (ORD) – The ORD provides a centralized database of information on various rare diseases, including Down syndrome. Their website offers an extensive list of references, research articles, and clinical trial information related to Down syndrome.

• Online Mendelian Inheritance in Man (OMIM) – OMIM is a comprehensive database that provides information on the genetic basis of human diseases, including Down syndrome. Their website offers detailed genetic information, associated genes, and inheritance patterns related to Down syndrome.

• The Down Syndrome Research and Treatment Foundation (DSRTF) – The DSRTF is a nonprofit organization that supports research, clinical trials, and advocacy efforts for Down syndrome. Their website provides information on ongoing research studies, resources for families, and opportunities for involvement in Down syndrome research.

In addition to these resources, there are many other scientific publications, research studies, and support organizations available that can provide further information on Down syndrome and related conditions. It is important to consult with healthcare professionals to ensure accurate and up-to-date information.

Genetic Testing Information

Genetic testing is an important method for diagnosing Down syndrome. This condition is caused by an extra copy of the chromosomes, which leads to the unbalanced division of cells during the development of the fetus. Genetic testing can determine whether a person has Down syndrome by analyzing their genes.

The most common test for Down syndrome is called the chromosomal analysis or karyotype. This test examines cells from a blood sample or other tissues to look for the extra chromosome 21. Additionally, there are other genetic tests that can detect specific genes associated with Down syndrome.

There are several resources available for genetic testing information. The National Institutes of Health’s Genetic Testing Registry provides information on genetic tests, including their purpose, methodology, and associated diseases. PubMed is another useful resource that provides scientific articles on genetics and related topics. OMIM is a database that provides information on genes and genetic disorders, including Down syndrome.

Genetic testing can also help determine the inheritance pattern of Down syndrome. In most cases, it is not inherited and occurs randomly. However, in some cases, Down syndrome can be inherited from a parent who carries a chromosomal rearrangement. Genetic testing can help identify these cases and provide information about the risks of having a child with Down syndrome.

The frequency of Down syndrome varies depending on the maternal age. The percentage of babies born with Down syndrome increases with the age of the mother. For example, at age 35, the risk is about 1 in 350, and by age 45, the risk is about 1 in 30.

Individuals with Down syndrome often have distinct facial features, such as a flat facial profile and upward-slanting eyes. They may also experience developmental delays, intellectual disabilities, and certain health conditions, such as heart defects and thyroid problems.

There are several genetic testing centers and advocacy organizations that provide support and resources for individuals with Down syndrome and their families. These organizations can provide information about genetic testing, clinical trials, research studies, and additional support services.

In conclusion, genetic testing is an essential tool for diagnosing Down syndrome and providing information about its causes and associated diseases. It can help determine the inheritance pattern and provide support for individuals and families affected by Down syndrome.

References:

• Capone, G., Chicoine, B., & Bulova, P. (2018). Down syndrome: Current perspectives. On PubMed. Retrieved from https://pubmed.ncbi.nlm.nih.gov/29386975/
• Down Syndrome. (2021). On OMIM. Retrieved from https://omim.org/entry/190685
• Down Syndrome. (2021). On PubMed. Retrieved from https://pubmed.ncbi.nlm.nih.gov/31050097/
• Roizen, N., & Patterson, D. (2003). Down’s syndrome. On PubMed. Retrieved from https://pubmed.ncbi.nlm.nih.gov/12915715/
• Down Syndrome. (2021). On ClinicalTrials.gov. Retrieved from https://clinicaltrials.gov/ct2/results?recrs=&cond=Down+Syndrome

Genetic and Rare Diseases Information Center

The Genetic and Rare Diseases Information Center (GARD) provides a reliable source of information on rare and genetic diseases. GARD is a program of the National Center for Advancing Translational Sciences (NCATS) and is part of the National Institutes of Health.

Down syndrome, also known as trisomy 21, is a rare genetic condition caused by an unbalanced chromosomal abnormality. It occurs when an individual has three copies of chromosome 21, instead of the usual two copies. Down syndrome is one of the most well-known genetic disorders and is associated with a range of physical and intellectual disabilities.

Studies have shown that Down syndrome is caused by the random inheritance of an extra chromosome 21. The exact causes of this chromosomal error are not fully understood, but scientific research and genetic studies have provided some insights. It is important to note that Down syndrome occurs in all races and is not related to the parents’ age or lifestyle.

The frequency of Down syndrome varies depending on the population. On average, it occurs in about 1 in every 1,000 live births. However, the chance of having a child with Down syndrome increases with maternal age.

Characteristics of Down syndrome include cognitive impairment, developmental delays, distinctive facial features, and certain health conditions, such as heart defects and thyroid gland dysfunction. It is important for individuals with Down syndrome and their families to receive support, information, and medical care tailored to their specific needs.

The Genetic and Rare Diseases Information Center offers resources for individuals and families affected by Down syndrome, as well as information on other genetic conditions. It provides a comprehensive catalog of rare diseases and associated genes through the Online Mendelian Inheritance in Man (OMIM) database. Additionally, the center supports research on rare diseases and provides up-to-date information on clinical trials, advocacy groups, and more.

For additional information on Down syndrome and related conditions, the following resources are recommended:

• PubMed – A database of biomedical literature, including research studies and clinical reports.
• ClinicalTrials.gov – A database of ongoing clinical trials for Down syndrome and other medical conditions.

In conclusion, the Genetic and Rare Diseases Information Center provides valuable support and information for individuals and families affected by Down syndrome. It is a reliable source for learning about the condition, finding clinical trials, and accessing resources for support and advocacy.

Patient Support and Advocacy Resources

Down syndrome is a genetic condition associated with the presence of an extra copy of chromosome 21 (trisomy 21). Individuals with Down syndrome have three copies of chromosome 21 instead of the usual two.

Patients and their families seeking information about Down syndrome and related resources can find helpful support and advocacy resources. Below are some websites and organizations that provide information, support, and advocate for individuals with Down syndrome:

• National Down Syndrome Congress (NDSC): The NDSC is a non-profit organization that provides advocacy, resources, and support for individuals with Down syndrome and their families. Their website offers information on Down syndrome, research studies, and links to other resources.
• National Down Syndrome Society (NDSS): The NDSS is another non-profit organization that promotes the understanding and acceptance of individuals with Down syndrome. Their website provides information on Down syndrome, resources for families, and updates on advocacy efforts.
• Down Syndrome Research and Treatment Foundation (DSRTF): The DSRTF is a non-profit organization that funds and supports research on Down syndrome. Their website provides information on ongoing research studies and opportunities for patient participation.
• ClinicalTrials.gov: ClinicalTrials.gov is a database of clinical studies conducted around the world. Patients and families can search for clinical trials related to Down syndrome by entering relevant keywords.

In addition to these resources, there are many other organizations, support groups, and online communities dedicated to providing information, support, and advocacy for individuals with Down syndrome and their families. It is important for patients and families to find the resources that best fit their specific needs and circumstances.

Research Studies from ClinicalTrialsgov

Down syndrome is a genetic condition caused by the presence of an extra copy of chromosome 21 in a person’s cells. It is also known as trisomy 21. Individuals with Down syndrome often have characteristic physical features and intellectual disabilities, but the severity of these symptoms can vary widely.

ClinicalTrials.gov is a valuable resource for finding information about research studies related to Down syndrome and other genetic diseases. The website provides a catalog of ongoing and completed clinical trials, as well as additional resources for patients and advocacy groups. Here are some research studies currently listed on ClinicalTrials.gov:

• A study on the genetic causes of Down syndrome, conducted by Dr. Robert Roizen and his team at the Down Syndrome Center at the Children’s Hospital of Pittsburgh. This study aims to learn more about the genes attached to chromosome 21 and their role in the development of Down syndrome.
• A clinical trial investigating the efficacy of a new therapy for individuals with Down syndrome who have an associated rare condition called Hirschsprung’s disease. This study is being conducted at several medical centers across the United States.
• An exploration of the frequency and characteristics of unbalanced chromosome abnormalities in individuals with Down syndrome. This study, conducted by Dr. Luigi Capone and his team at the Kennedy Krieger Institute, aims to provide valuable information about the causes and inheritance patterns of Down syndrome and other related conditions.

In addition to these studies, ClinicalTrials.gov provides many articles and publications related to research on Down syndrome. The website is a valuable resource for researchers, healthcare professionals, and individuals with Down syndrome and their families.

Catalog of Genes and Diseases from OMIM

The Catalog of Genes and Diseases from OMIM provides a comprehensive resource for testing, researching, and learning about the genetic causes of various diseases and conditions, including Down syndrome. OMIM, which stands for Online Mendelian Inheritance in Man, is a database that contains information about inherited genetic disorders.

Down syndrome is a relatively rare condition often caused by the presence of an extra copy of chromosome 21, known as trisomy 21. This random chromosomal division results in characteristic facial and physical features, as well as cognitive and developmental delays. While individuals with Down syndrome may have similar physical and cognitive traits, each person is unique and may experience a wide range of associated conditions and challenges.

The Catalog of Genes and Diseases from OMIM provides references and citations to scientific studies, clinical trials, and other resources related to Down syndrome and associated conditions. Through this catalog, researchers, advocates, and healthcare professionals can access information about the inheritance patterns, frequency, and genetic characteristics of Down syndrome and its associated conditions.

One of the important genes associated with Down syndrome is located on chromosome 21. Known as DYRK1A, this gene plays a role in brain development and may contribute to the cognitive impairments seen in individuals with Down syndrome. Additionally, the Catalog includes information about other genes and their roles in the development and progression of various characteristics and conditions associated with Down syndrome.

In addition to identifying and studying genes related to Down syndrome, the Catalog provides information about testing and resources for individuals and families affected by the condition. Genetic testing can help confirm a diagnosis of Down syndrome and provide information about associated conditions and potential health concerns. Additionally, the Catalog offers resources for advocacy, support, and education for individuals with Down syndrome and their families.

Researchers and healthcare professionals can utilize the Catalog of Genes and Diseases from OMIM to access the latest scientific articles, clinical trial information, and genetic studies related to Down syndrome. By staying informed and up-to-date with current research, they can contribute to the understanding and treatment of this complex condition.

In summary, the Catalog of Genes and Diseases from OMIM provides a valuable resource for learning about the genetic causes, clinical characteristics, and associated conditions of Down syndrome. It includes information about genes, inheritance patterns, testing, and resources for individuals with Down syndrome and their families. By leveraging the information from this catalog, researchers and healthcare professionals can continue to improve the lives of individuals with Down syndrome.

Scientific Articles on PubMed

PubMed is a widely-used online database that provides access to a large collection of scientific articles. There are numerous scientific articles available on PubMed that explore various aspects of Down syndrome. These articles provide valuable information to researchers, healthcare professionals, and individuals interested in learning more about this condition.

Additional information about Down syndrome can be found in scientific articles on PubMed. These articles explain the underlying causes of Down syndrome, which is the presence of an extra chromosome 21. This chromosome abnormality is the characteristic feature of this condition, and it occurs in every cell of an individual with Down syndrome.

Articles on PubMed often discuss the frequency of this condition. Down syndrome is one of the most common chromosomal disorders, occurring in approximately 1 in every 700-1,000 live births. It is also associated with advanced maternal age, as the risk of having a child with Down syndrome increases with the mother’s age at the time of conception.

Information on genes associated with Down syndrome can also be found in scientific articles on PubMed. Individuals with Down syndrome have an extra copy of chromosome 21, which results in an imbalance of gene expression. This can lead to various health conditions and characteristics associated with this condition.

Additionally, PubMed provides references to clinical trials and genetic research related to Down syndrome. Some studies focus on specific genes or genetic inheritance patterns that contribute to the development of this condition. This research can help in understanding the underlying causes and potential treatment options for individuals with Down syndrome.

Some of the scientific articles on PubMed also mention other diseases and conditions that are often seen in individuals with Down syndrome. These include facial features and gland diseases, which can occur as a result of the extra chromosome 21. Genetic testing is often recommended to learn more about these associated conditions and to provide additional information about a patient’s genetic makeup.

Various studies and clinical trials listed on PubMed examine the percentage of individuals with Down syndrome who have specific diseases or conditions. This information can be valuable in improving the medical care and treatment options available for individuals with Down syndrome.

In conclusion, PubMed is a valuable resource for accessing scientific articles on Down syndrome. These articles provide a wealth of information about the genetic and clinical aspects of this condition, as well as potential treatment options. Researchers and healthcare professionals can use this information to further their understanding and improve the care provided to individuals with Down syndrome.

References

1. omim: “Down Syndrome”, available from https://omim.org/entry/190685, characterstic of Down syndrome including genetic causes and associated diseases.
2. Additional resources and references about Down syndrome can be found on the website of the National Down Syndrome Society (NDSS), available from https://www.ndss.org/about-down-syndrome/down-syndrome/.
3. Roizen, N.J., Patterson, D. (2013). Down’s syndrome. The Lancet, 361(9365), 689-693. doi: 10.1016/S0140-6736(03)12512-2. A comprehensive review on Down syndrome.
4. Down Syndrome Research and Treatment Foundation. (n.d.). Learn about Down syndrome. Retrieved from https://www.dsrtf.org/learn-about-down-syndrome.html.
5. National Institute of Child Health and Human Development. (2018). Down Syndrome. Retrieved from https://www.nichd.nih.gov/health/topics/down/Pages/default.aspx. Information about Down syndrome and resources for support and advocacy.
6. ClinicalTrials.gov. (2020). Down Syndrome. Retrieved from https://www.clinicaltrials.gov/ct2/results?cond=Down+Syndrome&term=&cntry=&state=&city=&dist=. List of ongoing clinical trials related to Down syndrome.
7. Capone, G.T., et al. (2007). Down syndrome: clinical assessment and treatment. American Journal of Medical Genetics Part C: Seminars in Medical Genetics, 145C(4), 406-413. doi: 10.1002/ajmg.c.30149. Clinical characteristics and management of Down syndrome.