22q11 deletion syndrome: Genetics222q11 deletion syndrome: Genetics22q11 deletion syndrome: GeneticsEnglishGeneticsChild (0-12 years);Teen (13-18 years)BodyNAConditions and diseasesAdult (19+) CaregiversNA2018-04-18T04:00:00Z9.8000000000000048.6000000000000854.000000000000Health (A-Z) - ConditionsHealth A-Z<p>Learn about the genetic causes of 22q11 deletion syndrome, risk factors and confirming diagnosis.</p><h2>What is 22q11 deletion syndrome?</h2><p> <a href="/Article?contentid=3043&language=English">22q11 deletion syndrome (22q11DS)</a> is a genetic condition that affects about 1 in 2000 to 1 in 4000 children. 22q11DS is known by several other names including velo-cardio-facial syndrome (VCFS) and DiGeorge syndrome.</p><p>22q11DS can affect many parts of the body <a href="/Article?contentid=3045&language=English">including​</a>:</p><ul><li>the heart</li><li>the immune system</li><li>the palate (roof of the mouth).</li></ul><p>​It can also affect how a person learns.</p><h2>Key points</h2><ul><li>22q11DS is known by many names such as velo-cardio-facial syndrome and DiGeorge syndrome.</li><li>22q11DS is a genetic disorder. It results from a small missing piece of genetic material (DNA) on chromosome 22. This is called a deletion.</li><li>The 22q11 deletion happens most of the time by chance. In some families, the 22q11 deletion can be inherited from a parent.</li><li>Genetic testing on a small blood sample can help to make a diagnosis.</li><li>A genetic counsellor can help you understand the genetics of 22q11DS and the chances for it to happen in a child.</li></ul><h2>Causes of 22q11DS</h2><div class="akh-series"><div class="row"><div class="col-md-12"> <figure> <span class="asset-image-title">The organization of genetic material</span> <img src="https://assets.aboutkidshealth.ca/akhassets/What_is_a_gene_MED_ILL_EN.jpg" alt="Cell with chromosomes, which contain DNA strands with genes and nucleotides" /> </figure> <h3>Chromosome deletion</h3><p>DNA carries a person’s <a href="https://pie.med.utoronto.ca/htbw/module.html?module=genetics">genetic information</a>. DNA is organized into structures called chromosomes. Each cell of the body contains the same number of chromosomes and all of a person’s genetic information. Humans have 46 chromosomes arranged in 23 pairs, with two copies of each chromosome. </p><p>Chromosomes carry all of our genes. Genes determine how a person will grow and develop. Missing genetic information (such as a chromosome deletion) can lead to medical and developmental problems. How a person’s development or health will be affected depends on which genetic material is missing. </p></div></div></div><p>All chromosomes have a long (q) arm and a short (p) arm. People typically have two copies of chromosome 22. People with 22q11DS have a small piece of genetic material (genes) missing on the q arm of one of their two copies of chromosome 22. This is sometimes called a deletion. Even though it is small, the deletion of the 22q11.2 chromosome region involves many genes and can affect many parts of the body.</p> <figure class="asset-c-80"> <span class="asset-image-title">22q11 deletion</span> <img src="https://assets.aboutkidshealth.ca/akhassets/22q11_microdeletion_EN.jpg" alt="Chromosome 22 with missing genetic material" /> <figcaption class="asset-image-caption">This chromosome 22 pair shows a complete chromosome (A) and a chromosome with a deletion (B).</figcaption> </figure> <h3>How did your child get 22q11DS? </h3><p>Most of the time, 22q11DS is the result of a new genetic deletion that occurs when a baby is conceived. This is called a de novo deletion and occurs by chance in either the mom’s egg or the dad’s sperm. A de novo deletion is not caused by anything the parents did before or during the pregnancy. For parents who have a child with a de novo deletion, the chance of having another child with 22q11DS is low. </p> <figure class="asset-c-80"> <span class="asset-image-title"> <em>De novo</em> deletion of 22q11DS</span><img src="https://assets.aboutkidshealth.ca/akhassets/22q11_de_novo_deletion_EN.jpg" alt="Chromosome distribution from unaffected parents resulting in spontaneous new gene deletion before baby is conceived" /> <figcaption class="asset-image-caption">Most of the time, 22q11DS is the result of a new genetic deletion in the egg or sperm before the baby is conceived. This is called a <em>de novo</em> deletion and occurs by chance.</figcaption> </figure> <p>In some people with 22q11DS (about 10%), the deletion is inherited from a parent. Sometimes a parent might not know that they have 22q11DS until after they have a child diagnosed with this condition. A person who has 22q11DS has a 50% chance (1 in 2) of having a child with 22q11DS.</p> <figure class="asset-c-80"> <span class="asset-image-title">22q11DS inherited from a parent</span> <img src="https://assets.aboutkidshealth.ca/AKHAssets/IMD_22q11_inheritance_EN.jpg" alt="Chromosome distribution from an affected parent with 22q11 DS and an unaffected parent, producing two possible combinations" /> <figcaption class="asset-image-caption">22q11DS is caused by a deletion in chromosome 22. A person will have 22q11DS if one chromosome 22 in the pair has the deletion. In this example, the parent with 22q11DS has one chromosome 22 with a deletion and one intact chromosome 22 (without a deletion). If the baby inherits the intact chromosome 22, then the baby will not have 22q11DS. If the baby inherits the chromosome 22 with a deletion, then the baby will have 22q11DS.</figcaption> </figure> <p>You can speak to a genetic counsellor to discuss information regarding how 22q11DS happened in your family and your chances of having a child with 22q11DS.</p><h2>How 22q11DS is diagnosed</h2><p>If the doctor <a href="/Article?contentid=3043&language=English">suspects that a child has 22q11DS</a>, they may order genetic testing. Today, three different tests are able to detect 22q11DS. Each requires a small sample of blood. Some tests look for the 22q11 deletion; others look generally at the chromosomes structures for any deletion or duplication of genetic material. </p><p>Only one of these tests is typically needed to make a diagnosis of 22q11DS. The test that is ordered by your child's doctor is chosen based on your child’s presentation. </p><p>It usually takes several weeks to get these test results back depending on the test chosen and the laboratory. Ask your health-care provider about your specific situation.</p><p>These tests include:</p><h3>FISH (fluorescent in situ hybridization)</h3> <p>Fluorescent In Situ Hybridization (FISH) is a test that looks specifically for a deletion on chromosome 22. This test can miss small or atypical 22q11 deletions.</p><h3>Chromosomal microarray </h3><p>Chromosome microarray is a test that looks for extra or missing pieces across all the chromosomes. This test can detect small or atypical 22q11 deletions.</p><h3>MLPA</h3><p>MLPA is a DNA test that looks for missing or extra pieces in chromosome region 22q11. This test can detect small or atypical 22q11 deletions.</p>
Syndrome de délétion du chromosome 22q11 : GénétiqueSSyndrome de délétion du chromosome 22q11 : Génétique22q11 deletion syndrome: GeneticsFrenchGeneticsChild (0-12 years);Teen (13-18 years)BodyNAConditions and diseasesAdult (19+) CaregiversNA2018-04-18T04:00:00ZHealth (A-Z) - ConditionsHealth A-Z<p>Apprenez-en davantage sur les causes génétiques du syndrome de délétion du chromosome 22q11, ses facteurs de risque et sur la confirmation de son diagnostic.</p><h2>Qu’est-ce que le syndrome de délétion du chromosome 22q11?</h2><p>Le <a href="/Article?contentid=3043&language=French">syndrome de délétion du chromosome 22q11</a> est une maladie génétique qui touche un enfant sur 2 000 à un enfant sur 4 000. On connaît ce syndrome sous différents noms comme le syndrome vélo-cardio-facial et le syndrome de DiGeorge.</p><p>Le syndrome SD22q11 peut toucher <a href="/Article?contentid=3045&language=French">plusieurs parties du corps </a>dont :</p><ul><li>le cœur;</li><li>le système immunitaire;</li><li>le palais (la voûte de la bouche).</li></ul><p>Il peut aussi influencer les fonctions d’apprentissage d’une personne.</p><h2>À retenir</h2><ul><li>On connaît le syndrome de délétion du chromosome 22q11 (SD22q11) sous différents noms comme le syndrome vélo-cardio-facial et le syndrome de DiGeorge.</li><li>Ce syndrome est un trouble génétique. Il est causé par l’absence d’une petite section de matériel génétique (ADN) sur le chromosome 22. On parle alors d’une délétion.</li><li>La délétion 22q11 se produit par hasard la plupart du temps. Dans certaines familles, la délétion 22q11 peut être héritée de l’un ou l’autre des parents.</li><li>Un essai génétique réalisé à partir d’un échantillon de sang peut aider à poser un diagnostic.</li><li>Un conseiller en génétique peut vous aider à comprendre la génétique du syndrome de délétion du chromosome 22q11 et la probabilité qu’il puisse se produire chez un enfant.</li></ul><h2>Les causes du syndrome de délétion du chromosome 22q11</h2><div class="akh-series"><div class="row"><div class="col-md-12"> <figure><span class="asset-image-title">L’organisation du matériel génétique</span><img src="https://assets.aboutkidshealth.ca/akhassets/What_is_a_gene_MED_ILL_FR.jpg" alt="An optometrists chart for a young child" /> </figure> <h3>Délétion de chromosomes</h3><p>L’ADN est porteur des <a href="https://pie.med.utoronto.ca/htbw/module.html?module=genetics">renseignements génétiques</a> d’une personne. L’ADN est organisé selon des structures appelées chromosomes. Chaque cellule du corps comprend le même nombre de chromosomes et contient l’ensemble des renseignements génétiques d’une personne. Les êtres humains possèdent 46 chromosomes arrangés en 23 paires comptant chacune deux exemplaires de chaque chromosome.</p><p>Les chromosomes portent l’ensemble de nos gènes. Les gènes déterminent la façon dont une personne grandira et se développera. L’absence de certains renseignements génétiques (comme une délétion de chromosome) peut mener à des problèmes médicaux et de développement. La manière dont le développement ou la santé d’une personne sera touché dépend de la nature du matériel génétique manquant.</p></div></div></div><p>L’ensemble des chromosomes présente un bras long (bras q) et un bras court (bras p). Les êtres humains ont typiquement deux exemplaires du chromosome 22. Une petite section de matériel génétique (gènes) est absente sur le bras q de l’un des deux exemplaires du chromosome 22 chez les personnes atteintes du syndrome de délétion du chromosome 22q11. On parle parfois d’une délétion. Même si elle est petite, la délétion de la section 22q11 du chromosome implique plusieurs gènes et peut toucher plusieurs parties du corps.</p> <figure class="asset-c-80"><span class="asset-image-title">Délétion du chromosome 22q11</span><img src="https://assets.aboutkidshealth.ca/akhassets/22q11_microdeletion_FR.jpg" alt="An optometrists chart for a young child" /><figcaption class="asset-image-caption">Cette paire de chromosomes 22 montre un chromosome complet (A) et un chromosome qui présente une délétion (B).</figcaption> </figure> <h3>Comment votre enfant a-t-il contracté le syndrome de délétion du chromosome 22q11?</h3><p>La plupart du temps, le syndrome de délétion du chromosome 22q11 est le résultat d’une délétion génétique originale qui se produit au moment de la conception d’un bébé. On parle alors de délétion de novo et elle survient au hasard dans l’ovule de la mère ou le spermatozoïde du père. Les actions des parents avant et pendant la grossesse ne peuvent en aucun cas avoir provoqué une délétion de novo. Les parents dont l’un des enfants présente une délétion de novo sont peu susceptibles d’avoir un autre enfant atteint du syndrome SD22q11.</p> <figure class="asset-c-80"><span class="asset-image-title">Délétion de novo du syndrome de délétion du chromosome 22q11</span><img src="https://assets.aboutkidshealth.ca/akhassets/de_novo_mutation_FR.jpg" alt="An optometrists chart for a young child" /><figcaption class="asset-image-caption">La plupart du temps, un syndrome de délétion du chromosome 22q11 est le résultat d’une nouvelle délétion génétique se produisant dans l’ovule ou le spermatozoïde avant que le bébé ne soit conçu. On nomme ceci une délétion de novo et elle survient au hasard.</figcaption> </figure> <p>Chez certaines personnes aux prises avec ce syndrome (environ 10 % des cas), la délétion est héritée de l’un des parents. Parfois, un parent peut ignorer être porteur du syndrome de délétion du chromosome 22q11 jusqu’au moment du diagnostic de la maladie chez l’un de ses enfants. La probabilité qu’une personne atteinte du syndrome SD22q11 ait un enfant qui soit aussi atteint du syndrome est de 50 %.</p> <figure class="asset-c-80"><span class="asset-image-title">Syndrome de délétion du chromosome 22q11 hérité de l’un des parents</span><img src="https://assets.aboutkidshealth.ca/AKHAssets/IMD_22q11_inheritance_FR.jpg" alt="" /><figcaption class="asset-image-caption">La conformation 22q11 est causée par une délétion sur le chromosome 22. Une personne sera porteuse du syndrome de délétion du chromosome 22 si un chromosome de la paire présente une délétion. Dans le présent exemple, un parent porteur du SD22q11 possède un chromosome 22 avec une délétion et un second chromosome 22 qui est intact (sans délétion). Si le bébé hérite du chromosome 22 intact, il ne sera pas porteur du syndrome de délétion du chromosome 22q11. Si le bébé hérite du chromosome 22 portant une délétion, il sera porteur du SD22q11.</figcaption> </figure> <p>Vous pouvez consulter un conseiller en génétique afin d’en savoir davantage sur la façon dont ce syndrome est survenu dans votre famille et sur vos probabilités d’avoir un enfant qui en soit atteint.</p><h2>De quelle façon diagnostique-t-on le syndrome de délétion du chromosome 22q11?</h2><p>Si le médecin <a href="/Article?contentid=3043&language=French">suspecte qu’un enfant est atteint du syndrome de délétion du chromosome 22q11</a>, il peut prescrire un essai génétique. De nos jours, trois différents essais génétiques peuvent détecter le syndrome SD22q11. Chacun requiert la prise d’un petit échantillon de sang. Certains essais visent à détecter la délétion du chromosome 22q11; d’autres observent la structure des chromosomes en général afin de déceler toute délétion ou duplication du matériel génétique. Un seul de ces essais est habituellement nécessaire afin de poser un diagnostic du syndrome de délétion du chromosome 22q11. L’essai qui est prescrit par le médecin de votre enfant est choisi en fonction de son état.</p><p>Les résultats des essais sont habituellement disponibles après plusieurs semaines en fonction de l’essai demandé et du laboratoire. Consultez votre fournisseur de soins de santé pour en apprendre davantage sur votre situation.</p><p>Ces essais comprennent :</p><h3>L’hybridation in situ en fluorescence </h3><p>L’hybridation in situ en fluorescence est un essai qui permet de rechercher de manière spécifique une délétion le chromosome 22. Elle peut omettre de petites délétions sur la région chromosomique 22q11 ou des délétions atypiques.</p><h3>La puce d’hybridation génomique comparative</h3><p>La puce d’hybridation génomique comparative est un essai qui recherche des sections surnuméraires ou manquantes sur l’ensemble des chromosomes. Cet essai peut détecter de petites délétions sur la région chromosomique 22q11 ou des délétions atypiques.</p><h3>L’amplification multiplex de sonde nucléique</h3><p>L’amplification multiplex de sonde nucléique est un essai d’ADN qui recherche des sections surnuméraires ou manquantes sur la région chromosomique 22q11. Cet essai peut détecter de petites délétions sur la région chromosomique 22q11 ou des délétions atypiques.</p>

 

 

 

 

22q11 deletion syndrome: Genetics3044.0000000000022q11 deletion syndrome: Genetics22q11 deletion syndrome: Genetics2EnglishGeneticsChild (0-12 years);Teen (13-18 years)BodyNAConditions and diseasesAdult (19+) CaregiversNA2018-04-18T04:00:00Z9.8000000000000048.6000000000000854.000000000000Health (A-Z) - ConditionsHealth A-Z<p>Learn about the genetic causes of 22q11 deletion syndrome, risk factors and confirming diagnosis.</p><h2>What is 22q11 deletion syndrome?</h2><p> <a href="/Article?contentid=3043&language=English">22q11 deletion syndrome (22q11DS)</a> is a genetic condition that affects about 1 in 2000 to 1 in 4000 children. 22q11DS is known by several other names including velo-cardio-facial syndrome (VCFS) and DiGeorge syndrome.</p><p>22q11DS can affect many parts of the body <a href="/Article?contentid=3045&language=English">including​</a>:</p><ul><li>the heart</li><li>the immune system</li><li>the palate (roof of the mouth).</li></ul><p>​It can also affect how a person learns.</p><h2>Key points</h2><ul><li>22q11DS is known by many names such as velo-cardio-facial syndrome and DiGeorge syndrome.</li><li>22q11DS is a genetic disorder. It results from a small missing piece of genetic material (DNA) on chromosome 22. This is called a deletion.</li><li>The 22q11 deletion happens most of the time by chance. In some families, the 22q11 deletion can be inherited from a parent.</li><li>Genetic testing on a small blood sample can help to make a diagnosis.</li><li>A genetic counsellor can help you understand the genetics of 22q11DS and the chances for it to happen in a child.</li></ul><h2>Causes of 22q11DS</h2><div class="akh-series"><div class="row"><div class="col-md-12"> <figure> <span class="asset-image-title">The organization of genetic material</span> <img src="https://assets.aboutkidshealth.ca/akhassets/What_is_a_gene_MED_ILL_EN.jpg" alt="Cell with chromosomes, which contain DNA strands with genes and nucleotides" /> </figure> <h3>Chromosome deletion</h3><p>DNA carries a person’s <a href="https://pie.med.utoronto.ca/htbw/module.html?module=genetics">genetic information</a>. DNA is organized into structures called chromosomes. Each cell of the body contains the same number of chromosomes and all of a person’s genetic information. Humans have 46 chromosomes arranged in 23 pairs, with two copies of each chromosome. </p><p>Chromosomes carry all of our genes. Genes determine how a person will grow and develop. Missing genetic information (such as a chromosome deletion) can lead to medical and developmental problems. How a person’s development or health will be affected depends on which genetic material is missing. </p></div></div></div><p>All chromosomes have a long (q) arm and a short (p) arm. People typically have two copies of chromosome 22. People with 22q11DS have a small piece of genetic material (genes) missing on the q arm of one of their two copies of chromosome 22. This is sometimes called a deletion. Even though it is small, the deletion of the 22q11.2 chromosome region involves many genes and can affect many parts of the body.</p> <figure class="asset-c-80"> <span class="asset-image-title">22q11 deletion</span> <img src="https://assets.aboutkidshealth.ca/akhassets/22q11_microdeletion_EN.jpg" alt="Chromosome 22 with missing genetic material" /> <figcaption class="asset-image-caption">This chromosome 22 pair shows a complete chromosome (A) and a chromosome with a deletion (B).</figcaption> </figure> <h3>How did your child get 22q11DS? </h3><p>Most of the time, 22q11DS is the result of a new genetic deletion that occurs when a baby is conceived. This is called a de novo deletion and occurs by chance in either the mom’s egg or the dad’s sperm. A de novo deletion is not caused by anything the parents did before or during the pregnancy. For parents who have a child with a de novo deletion, the chance of having another child with 22q11DS is low. </p> <figure class="asset-c-80"> <span class="asset-image-title"> <em>De novo</em> deletion of 22q11DS</span><img src="https://assets.aboutkidshealth.ca/akhassets/22q11_de_novo_deletion_EN.jpg" alt="Chromosome distribution from unaffected parents resulting in spontaneous new gene deletion before baby is conceived" /> <figcaption class="asset-image-caption">Most of the time, 22q11DS is the result of a new genetic deletion in the egg or sperm before the baby is conceived. This is called a <em>de novo</em> deletion and occurs by chance.</figcaption> </figure> <p>In some people with 22q11DS (about 10%), the deletion is inherited from a parent. Sometimes a parent might not know that they have 22q11DS until after they have a child diagnosed with this condition. A person who has 22q11DS has a 50% chance (1 in 2) of having a child with 22q11DS.</p> <figure class="asset-c-80"> <span class="asset-image-title">22q11DS inherited from a parent</span> <img src="https://assets.aboutkidshealth.ca/AKHAssets/IMD_22q11_inheritance_EN.jpg" alt="Chromosome distribution from an affected parent with 22q11 DS and an unaffected parent, producing two possible combinations" /> <figcaption class="asset-image-caption">22q11DS is caused by a deletion in chromosome 22. A person will have 22q11DS if one chromosome 22 in the pair has the deletion. In this example, the parent with 22q11DS has one chromosome 22 with a deletion and one intact chromosome 22 (without a deletion). If the baby inherits the intact chromosome 22, then the baby will not have 22q11DS. If the baby inherits the chromosome 22 with a deletion, then the baby will have 22q11DS.</figcaption> </figure> <p>You can speak to a genetic counsellor to discuss information regarding how 22q11DS happened in your family and your chances of having a child with 22q11DS.</p><h2>How 22q11DS is diagnosed</h2><p>If the doctor <a href="/Article?contentid=3043&language=English">suspects that a child has 22q11DS</a>, they may order genetic testing. Today, three different tests are able to detect 22q11DS. Each requires a small sample of blood. Some tests look for the 22q11 deletion; others look generally at the chromosomes structures for any deletion or duplication of genetic material. </p><p>Only one of these tests is typically needed to make a diagnosis of 22q11DS. The test that is ordered by your child's doctor is chosen based on your child’s presentation. </p><p>It usually takes several weeks to get these test results back depending on the test chosen and the laboratory. Ask your health-care provider about your specific situation.</p><p>These tests include:</p><h3>FISH (fluorescent in situ hybridization)</h3> <p>Fluorescent In Situ Hybridization (FISH) is a test that looks specifically for a deletion on chromosome 22. This test can miss small or atypical 22q11 deletions.</p><h3>Chromosomal microarray </h3><p>Chromosome microarray is a test that looks for extra or missing pieces across all the chromosomes. This test can detect small or atypical 22q11 deletions.</p><h3>MLPA</h3><p>MLPA is a DNA test that looks for missing or extra pieces in chromosome region 22q11. This test can detect small or atypical 22q11 deletions.</p>https://assets.aboutkidshealth.ca/akhassets/What_is_a_gene_MED_ILL_EN.jpg22q11 deletion syndrome: GeneticsFalse