Microdeletion syndrome: Difference between revisions
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{{Short description|A genetic disorder caused by the deletion of a small chromosomal segment}} | |||
'''Microdeletion syndrome''' is a genetic disorder characterized by the deletion of a small segment of a chromosome. These deletions can lead to a variety of developmental and physical abnormalities, depending on the specific genes that are lost. Microdeletion syndromes are often identified through genetic testing, such as [[fluorescence in situ hybridization]] (FISH) or [[comparative genomic hybridization]] (CGH). | |||
Microdeletion syndromes are | ==Overview== | ||
Microdeletion syndromes are a subset of [[chromosomal deletion]] syndromes, where a small part of a chromosome is missing. These deletions can occur on any chromosome and can vary in size. The loss of genetic material can disrupt the function of multiple genes, leading to a range of clinical features. | |||
== | ==Common Microdeletion Syndromes== | ||
Several well-known microdeletion syndromes have been identified, each associated with specific clinical features: | |||
===22q11.2 Deletion Syndrome=== | |||
[[22q11.2 deletion syndrome]], also known as DiGeorge syndrome or velocardiofacial syndrome, is one of the most common microdeletion syndromes. It is caused by the deletion of a small segment on chromosome 22. Clinical features can include congenital heart defects, cleft palate, immune deficiencies, and developmental delays. | |||
== | ===Williams Syndrome=== | ||
[[Williams syndrome]] is caused by a deletion on chromosome 7. It is characterized by distinctive facial features, cardiovascular problems, and developmental delays. Individuals with Williams syndrome often have a unique cognitive profile, with strengths in verbal abilities and weaknesses in visuospatial tasks. | |||
===Prader-Willi Syndrome=== | |||
[[Prader-Willi syndrome]] results from a deletion on chromosome 15. It is associated with hypotonia, obesity, intellectual disability, and endocrine abnormalities. The syndrome is caused by the loss of paternal genes in the 15q11-q13 region. | |||
== | ===Angelman Syndrome=== | ||
[[Angelman syndrome]] is caused by a deletion on the maternal chromosome 15, in the same region as Prader-Willi syndrome. It is characterized by severe intellectual disability, lack of speech, seizures, and a happy demeanor. | |||
==Diagnosis== | |||
Microdeletion syndromes are typically diagnosed using genetic testing techniques. [[Fluorescence in situ hybridization]] (FISH) can be used to detect specific deletions, while [[comparative genomic hybridization]] (CGH) allows for the detection of larger deletions across the genome. [[Next-generation sequencing]] (NGS) is also increasingly used to identify microdeletions. | |||
== | ==Management== | ||
Management of microdeletion syndromes is often multidisciplinary, involving specialists in genetics, cardiology, neurology, and developmental pediatrics. Treatment is symptomatic and supportive, focusing on addressing the specific medical and developmental needs of the individual. | |||
==Images== | |||
[[File:Chromosome_deletion.png|thumb|right|Diagram of a chromosomal deletion.]] | |||
==Related pages== | |||
* [[Chromosomal deletion]] | |||
* [[Genetic disorder]] | * [[Genetic disorder]] | ||
* [[ | * [[Fluorescence in situ hybridization]] | ||
* [[ | * [[Comparative genomic hybridization]] | ||
[[Category:Genetic disorders]] | [[Category:Genetic disorders]] | ||
[[Category: | [[Category:Chromosomal abnormalities]] | ||
Revision as of 17:43, 18 February 2025
A genetic disorder caused by the deletion of a small chromosomal segment
Microdeletion syndrome is a genetic disorder characterized by the deletion of a small segment of a chromosome. These deletions can lead to a variety of developmental and physical abnormalities, depending on the specific genes that are lost. Microdeletion syndromes are often identified through genetic testing, such as fluorescence in situ hybridization (FISH) or comparative genomic hybridization (CGH).
Overview
Microdeletion syndromes are a subset of chromosomal deletion syndromes, where a small part of a chromosome is missing. These deletions can occur on any chromosome and can vary in size. The loss of genetic material can disrupt the function of multiple genes, leading to a range of clinical features.
Common Microdeletion Syndromes
Several well-known microdeletion syndromes have been identified, each associated with specific clinical features:
22q11.2 Deletion Syndrome
22q11.2 deletion syndrome, also known as DiGeorge syndrome or velocardiofacial syndrome, is one of the most common microdeletion syndromes. It is caused by the deletion of a small segment on chromosome 22. Clinical features can include congenital heart defects, cleft palate, immune deficiencies, and developmental delays.
Williams Syndrome
Williams syndrome is caused by a deletion on chromosome 7. It is characterized by distinctive facial features, cardiovascular problems, and developmental delays. Individuals with Williams syndrome often have a unique cognitive profile, with strengths in verbal abilities and weaknesses in visuospatial tasks.
Prader-Willi Syndrome
Prader-Willi syndrome results from a deletion on chromosome 15. It is associated with hypotonia, obesity, intellectual disability, and endocrine abnormalities. The syndrome is caused by the loss of paternal genes in the 15q11-q13 region.
Angelman Syndrome
Angelman syndrome is caused by a deletion on the maternal chromosome 15, in the same region as Prader-Willi syndrome. It is characterized by severe intellectual disability, lack of speech, seizures, and a happy demeanor.
Diagnosis
Microdeletion syndromes are typically diagnosed using genetic testing techniques. Fluorescence in situ hybridization (FISH) can be used to detect specific deletions, while comparative genomic hybridization (CGH) allows for the detection of larger deletions across the genome. Next-generation sequencing (NGS) is also increasingly used to identify microdeletions.
Management
Management of microdeletion syndromes is often multidisciplinary, involving specialists in genetics, cardiology, neurology, and developmental pediatrics. Treatment is symptomatic and supportive, focusing on addressing the specific medical and developmental needs of the individual.
