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Smith-Magenis syndrome
- Other Names:
Chromosome 17p11.2 deletion syndrome; SMSChromosome 17p11.2 deletion syndrome; SMS
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Disease at a Glance
Summary
Smith-Magenis syndrome (SMS) is a developmental disorder that affects many parts of the body. The major features of this condition include mild to moderate intellectual disability, delayed speech and language skills, distinctive facial features, sleep disturbances, and behavioral problems. Most people with SMS have a deletion of genetic material in each cell from a specific region of chromosome 17. Although this region contains multiple genes, the loss of one particular gene, RAI1, is responsible for most of the features of the condition. In most of these cases, the deletion is not inherited, occurring randomly during the formation of eggs or sperm, or in early fetal development. In about 10% of cases, SMS is caused by a genetic change in the RAI1 gene. These genetic changes may occur randomly, or may be inherited from a parent in an autosomal dominant manner.
Estimated Number of People with this Disease
In the U.S., this disease is estimated to be fewer than
50,000
What Information Does GARD Have For This Disease?
Many rare diseases have limited information. Currently GARD is able to provide the following information for this disease:
*Data may be currently unavailable to GARD at this time.
Categories
When do symptoms of this disease begin?
The most common ages for symptoms of a disease to begin is called age of onset. Age of onset can vary for different diseases and may be used by a doctor to determine the diagnosis. For some diseases, symptoms may begin in a single age range or several age ranges. For other diseases, symptoms may begin any time during a person's life.
Prenatal
Before Birth
Newborn Selected
Birth-4 weeks
Infant Selected
1-23 months
Child Selected
2-11 years
Adolescent Selected
12-18 years
Adult Selected
19-65 years
Older Adult
65+ years
The common ages for symptoms to begin in this disease are shown above by the colored icon(s).
Symptoms
These symptoms may be different from person to person. Some people may have more symptoms than others and symptoms can range from mild to severe. This list does not include every symptom.
This disease might cause these symptoms:
This disease might cause these symptoms:
Respiratory System
72 Symptoms
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Respiratory System
The respiratory system is made up of the lungs and the nose, mouth, throat, voice box, windpipe, diaphragm, and muscles of the chest wall. This system controls breathing, providing the body with oxygen and getting rid of carbon dioxide. Common symptoms of problems in the respiratory system include chronic cough, shortness of breath, chronic chest pain, coughing up blood, and chronic mucus production. Diseases of the respiratory system may be diagnosed and treated by a pulmonologist.
72 Symptoms
Causes
Genetic Disease
Smith-Magenis syndrome is a genetic disease, which means that it is caused by one or more genes not working correctly.
Disease causing variants in the following gene(s) are known to cause this disease: RAI1
Questions:
What is a gene?
Genes are part of our DNA, the basic genetic material found in each of our body's cells. Cells are the building blocks of all living things and specialized cells form our body's organs and tissues. DNA is found in the nucleus of a cell and, in humans, is packaged into 23 pairs of chromosomes with the help of special proteins.
Each gene performs a different job in our cells. Some genes serve as the instructions to make proteins. Proteins are needed for the structure, function, and regulation of the body's cells, tissues, and organs. Some genes can turn other genes on or off. Others make RNA molecules that are involved in chemical reactions in the body.
Sources to Learn More: What is a gene? (MedlinePlus) ; What's a Gene? (NHGRI) ; What are proteins and what do they do? (MedlinePlus)Genes are part of our DNA, the basic genetic material found in each of our body's cells. Cells are the building blocks of all living things and specialized cells form our body's organs and tissues. DNA is found in the nucleus of a cell and, in humans, is packaged into 23 pairs of chromosomes with the help of special proteins.
Each gene performs a different job in our cells. Some genes serve as the instructions to make proteins. Proteins are needed for the structure, function, and regulation of the body's cells, tissues, and organs. Some genes can turn other genes on or off. Others make RNA molecules that are involved in chemical reactions in the body.
Sources to Learn More: What is a gene? (MedlinePlus) ; What's a Gene? (NHGRI) ; What are proteins and what do they do? (MedlinePlus)
Each gene performs a different job in our cells. Some genes serve as the instructions to make proteins. Proteins are needed for the structure, function, and regulation of the body's cells, tissues, and organs. Some genes can turn other genes on or off. Others make RNA molecules that are involved in chemical reactions in the body.
Sources to Learn More: What is a gene? (MedlinePlus) ; What's a Gene? (NHGRI) ; What are proteins and what do they do? (MedlinePlus)Genes are part of our DNA, the basic genetic material found in each of our body's cells. Cells are the building blocks of all living things and specialized cells form our body's organs and tissues. DNA is found in the nucleus of a cell and, in humans, is packaged into 23 pairs of chromosomes with the help of special proteins.
Each gene performs a different job in our cells. Some genes serve as the instructions to make proteins. Proteins are needed for the structure, function, and regulation of the body's cells, tissues, and organs. Some genes can turn other genes on or off. Others make RNA molecules that are involved in chemical reactions in the body.
Sources to Learn More: What is a gene? (MedlinePlus) ; What's a Gene? (NHGRI) ; What are proteins and what do they do? (MedlinePlus)
What is a genetic variant?
A genetic variant is a change in a gene's code or DNA sequence that causes the gene to be different than found in most people. A benign variant does not cause health problems or disease because the change does not affect how the gene works. A pathogenic variant does cause health problems or disease because the change does affect how the gene works. A pathogenic variant may also be called a mutation or a disease-causing variant.
Variants can result from DNA copying mistakes made during cell division or certain environmental exposures. Variants that occur in the egg or sperm (germline mutations) can be passed on to offspring, while variants that occur in other body cells (somatic mutations) are not passed on.
Sources to Learn More: What is a genetic variant and how do variants occur? (MedlinePlus); Definition of Variant (NCI); Mutation definition, illustration, and related terms (NHGRI)A genetic variant is a change in a gene's code or DNA sequence that causes the gene to be different than found in most people. A benign variant does not cause health problems or disease because the change does not affect how the gene works. A pathogenic variant does cause health problems or disease because the change does affect how the gene works. A pathogenic variant may also be called a mutation or a disease-causing variant.
Variants can result from DNA copying mistakes made during cell division or certain environmental exposures. Variants that occur in the egg or sperm (germline mutations) can be passed on to offspring, while variants that occur in other body cells (somatic mutations) are not passed on.
Sources to Learn More: What is a genetic variant and how do variants occur? (MedlinePlus); Definition of Variant (NCI); Mutation definition, illustration, and related terms (NHGRI)
Variants can result from DNA copying mistakes made during cell division or certain environmental exposures. Variants that occur in the egg or sperm (germline mutations) can be passed on to offspring, while variants that occur in other body cells (somatic mutations) are not passed on.
Sources to Learn More: What is a genetic variant and how do variants occur? (MedlinePlus); Definition of Variant (NCI); Mutation definition, illustration, and related terms (NHGRI)A genetic variant is a change in a gene's code or DNA sequence that causes the gene to be different than found in most people. A benign variant does not cause health problems or disease because the change does not affect how the gene works. A pathogenic variant does cause health problems or disease because the change does affect how the gene works. A pathogenic variant may also be called a mutation or a disease-causing variant.
Variants can result from DNA copying mistakes made during cell division or certain environmental exposures. Variants that occur in the egg or sperm (germline mutations) can be passed on to offspring, while variants that occur in other body cells (somatic mutations) are not passed on.
Sources to Learn More: What is a genetic variant and how do variants occur? (MedlinePlus); Definition of Variant (NCI); Mutation definition, illustration, and related terms (NHGRI)
What is a genetic disease?
A genetic disease is a disease caused by a change in part of a person's DNA. Genetic diseases may be caused by genetic changes in a single gene, in multiple genes, by a combination of genetic changes and environmental factors (multifactorial inheritance), or changes in chromosomes.
Genetic diseases may be caused by genetic changes that are inherited from the parents and are present at birth, like sickle cell disease. Other genetic diseases present at birth may be caused by random genetic changes that happen while the egg or the sperm is forming or soon after fertilization.
Some diseases, like many cancers, are caused by genetic changes that happen during a person's life. These are known as acquired or somatic cell genetic changes. Such genetic changes are not inherited from a parent, but happen either randomly or due to some environmental exposure (such as cigarette smoke).
Sources to Learn More: Genetic Disorders (MedlinePlus) ; Genetic Disorders (NHGRI)A genetic disease is a disease caused by a change in part of a person's DNA. Genetic diseases may be caused by genetic changes in a single gene, in multiple genes, by a combination of genetic changes and environmental factors (multifactorial inheritance), or changes in chromosomes.
Genetic diseases may be caused by genetic changes that are inherited from the parents and are present at birth, like sickle cell disease. Other genetic diseases present at birth may be caused by random genetic changes that happen while the egg or the sperm is forming or soon after fertilization.
Some diseases, like many cancers, are caused by genetic changes that happen during a person's life. These are known as acquired or somatic cell genetic changes. Such genetic changes are not inherited from a parent, but happen either randomly or due to some environmental exposure (such as cigarette smoke).
Sources to Learn More: Genetic Disorders (MedlinePlus) ; Genetic Disorders (NHGRI)
Genetic diseases may be caused by genetic changes that are inherited from the parents and are present at birth, like sickle cell disease. Other genetic diseases present at birth may be caused by random genetic changes that happen while the egg or the sperm is forming or soon after fertilization.
Some diseases, like many cancers, are caused by genetic changes that happen during a person's life. These are known as acquired or somatic cell genetic changes. Such genetic changes are not inherited from a parent, but happen either randomly or due to some environmental exposure (such as cigarette smoke).
Sources to Learn More: Genetic Disorders (MedlinePlus) ; Genetic Disorders (NHGRI)A genetic disease is a disease caused by a change in part of a person's DNA. Genetic diseases may be caused by genetic changes in a single gene, in multiple genes, by a combination of genetic changes and environmental factors (multifactorial inheritance), or changes in chromosomes.
Genetic diseases may be caused by genetic changes that are inherited from the parents and are present at birth, like sickle cell disease. Other genetic diseases present at birth may be caused by random genetic changes that happen while the egg or the sperm is forming or soon after fertilization.
Some diseases, like many cancers, are caused by genetic changes that happen during a person's life. These are known as acquired or somatic cell genetic changes. Such genetic changes are not inherited from a parent, but happen either randomly or due to some environmental exposure (such as cigarette smoke).
Sources to Learn More: Genetic Disorders (MedlinePlus) ; Genetic Disorders (NHGRI)
Inheritance
All individuals inherit two copies of most genes. The number of copies of a gene that need to have a disease-causing variant affects the way a disease is inherited. This disease is inherited in the following pattern(s):
Questions:
Autosomal dominant inheritance
Autosomal means the gene is located on any chromosome except the X or Y chromosomes (sex chromosomes). Genes, like chromosomes, usually come in pairs. Dominant means that only one copy of the responsible gene (causal gene) must have a disease-causing change (pathogenic variant) in order for a person to have the disease. Mutation is an older term that is still sometimes used to mean pathogenic variant.
In some cases, a person inherits the pathogenic variant from a parent who has the genetic disease. In other cases, the disease occurs because of a new pathogenic variant (de novo) in the causal gene and there is no family history of the disease.
Each child of an individual with an autosomal dominant disease has a 50% (1 in 2) chance of inheriting the variant and the disease. Typically, children who inherit a dominant variant will have the disease, but they may be more or less severely impacted than their parent. Sometimes a person may have a pathogenic variant for an autosomal dominant disease and show no signs or symptoms of the disease.Autosomal means the gene is located on any chromosome except the X or Y chromosomes (sex chromosomes). Genes, like chromosomes, usually come in pairs. Dominant means that only one copy of the responsible gene (causal gene) must have a disease-causing change (pathogenic variant) in order for a person to have the disease. Mutation is an older term that is still sometimes used to mean pathogenic variant.
In some cases, a person inherits the pathogenic variant from a parent who has the genetic disease. In other cases, the disease occurs because of a new pathogenic variant (de novo) in the causal gene and there is no family history of the disease.
Each child of an individual with an autosomal dominant disease has a 50% (1 in 2) chance of inheriting the variant and the disease. Typically, children who inherit a dominant variant will have the disease, but they may be more or less severely impacted than their parent. Sometimes a person may have a pathogenic variant for an autosomal dominant disease and show no signs or symptoms of the disease.
In some cases, a person inherits the pathogenic variant from a parent who has the genetic disease. In other cases, the disease occurs because of a new pathogenic variant (de novo) in the causal gene and there is no family history of the disease.
Each child of an individual with an autosomal dominant disease has a 50% (1 in 2) chance of inheriting the variant and the disease. Typically, children who inherit a dominant variant will have the disease, but they may be more or less severely impacted than their parent. Sometimes a person may have a pathogenic variant for an autosomal dominant disease and show no signs or symptoms of the disease.Autosomal means the gene is located on any chromosome except the X or Y chromosomes (sex chromosomes). Genes, like chromosomes, usually come in pairs. Dominant means that only one copy of the responsible gene (causal gene) must have a disease-causing change (pathogenic variant) in order for a person to have the disease. Mutation is an older term that is still sometimes used to mean pathogenic variant.
In some cases, a person inherits the pathogenic variant from a parent who has the genetic disease. In other cases, the disease occurs because of a new pathogenic variant (de novo) in the causal gene and there is no family history of the disease.
Each child of an individual with an autosomal dominant disease has a 50% (1 in 2) chance of inheriting the variant and the disease. Typically, children who inherit a dominant variant will have the disease, but they may be more or less severely impacted than their parent. Sometimes a person may have a pathogenic variant for an autosomal dominant disease and show no signs or symptoms of the disease.
The National Library of Medicine's Unified Medical Language System (UMLS) is used to classify and organize diseases and disease categories.
Data from Orphanet and Human Phenotype Ontology (HPO) are used to provide information on a disease's symptoms, genes, inheritance, population estimates, and more.
National Academies of Sciences, Engineering, and Medicine. 2015. Improving Diagnosis in Health Care. Washington, DC: The National Academies Press.
U.S. Department of Health and Human Services, Office of Disease Prevention and Health Promotion. (2015). Health Literacy Online: A Guide for Simplifying the User Experience.
- Reference: Access aggregated data from Orphanet at Orphadata. Orphanet is an online database of rare diseases and orphan drugs. Copyright, INSERM 1997.
- Reference: Download data from HPO. Kohler S, Gargano M, Matentzoglu N, et al., The Human Phenotype Ontology in 2021, Nucleic Acids Research, Volume 49, Issue D1, 8 January 2021, Pages D1207–D1217.
- Reference: MedGen Data Downloads and FTP
- Reference: Data from the Newborn Screening Coding and Terminology Guide is available here. Downs SM, van Dyck PC, Rinaldo P, et al. Improving newborn screening laboratory test ordering and result reporting using health information exchange . J Am Med Inform Assoc. 2010 Jan-Feb;17(1):13-8.
National Academies of Sciences, Engineering, and Medicine. 2015. Improving Diagnosis in Health Care. Washington, DC: The National Academies Press.
U.S. Department of Health and Human Services, Office of Disease Prevention and Health Promotion. (2015). Health Literacy Online: A Guide for Simplifying the User Experience.
Last Updated: Nov. 8, 2021