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Trisomy 13 (Patau syndrome)TTrisomy 13 (Patau syndrome)Trisomy 13 (Patau syndrome)EnglishGeneticsChild (0-12 years)BodyNAConditions and diseasesCaregivers Adult (19+)NA2016-07-19T04:00:00Z11.900000000000039.4000000000000995.000000000000Health (A-Z) - ConditionsHealth A-Z<p>Information for parents about trisomy 13, a rare genetic condition that causes developmental delay and affects many different organ systems.</p><h2>What is a trisomy?<br></h2><p>The term trisomy (say: TRY-so-mee) means that there are three chromosomes, rather than the usual pair of chromosomes. For example, a baby with <a href="/Article?contentid=9&language=English">Down syndrome</a> usually has three copies of chromosome 21, rather than the usual pair. The condition is thus called “trisomy 21.”</p><h2>What is trisomy 13?</h2><p>Trisomy 13 is a rare chromosome abnormality that affects approximately one in every 8,000 to 12,000 live births. Babies with trisomy 13 have many abnormalities, involving nearly every organ system in the body, as well as developmental delay. Trisomy 13 is also called Patau syndrome, after the physician who first described the disorder.</p> <figure class="asset-c-80"> <span class="asset-image-title">Patau syndrome karyotype</span> <img src="https://assets.aboutkidshealth.ca/akhassets/Trisomy_13_Patau_syndrome_MED_ILL_EN.jpg" alt="Pairs of chromosomes in a female with an extra copy of chromosome 13" /> <figcaption class="asset-image-caption">People with Patau syndrome have an extra copy of chromosome 13.</figcaption> </figure> <br><h2>Key points</h2> <ul> <li>Trisomy 13 is a rare condition caused by an extra copy of chromosome 13. </li> <li>Babies with trisomy 13 have many abnormalities, involving nearly every organ system in the body, as well as developmental delay. </li> <li>It is difficult to predict the life expectancy of a baby with trisomy 13. </li> <li>Parents of a baby with trisomy 13 are encouraged to seek genetic counselling.</li> </ul><h2>Signs and symptoms of trisomy 13</h2><p>Babies with trisomy 13 often have a normal birth weight, a small head and a sloping forehead. Noses are usually large (“bulbous”), ears are low-set and unusual in shape, eye defects occur frequently, and cleft lip and palate as well as heart defects are very common. Many babies with trisomy 13 are born with small areas of missing skin on the scalp (cutis aplasia), which resemble ulcers.</p><p>The <a href="https://pie.med.utoronto.ca/htbw/module.html?module=brain-child">brains</a> in babies with trisomy 13 usually have major structural problems and often, the brain does not divide properly into two hemispheres, resulting in a condition called holoprosencephaly. Many babies with trisomy 13 have extra fingers and toes (polydactyly). Some present with a sac attached to the abdomen in the area of the umbilical cord (omphalocele), which contains some of the abdominal organs, as well as <a href="/Article?contentid=371&language=English">spina bifida</a>. Girls may have an abnormally shaped uterus, called a bicornuate uterus. In boys, the <a href="/Article?contentid=884&language=English">testes sometimes fail to descend into the scrotum</a>.</p><h2>What causes trisomy 13?</h2><p>Usually each egg and sperm cell contains 23 chromosomes. At the time of <a href="/Article?contentid=310&language=English">fertilization</a>, the sperm and egg unite and create a cell with 23 chromosome pairs, or 46 chromosomes. In this manner, a child receives exactly half of their genetic material from each parent. </p><p>Sometimes, an error occurs when the egg or sperm cell is forming, causing it to have an extra chromosome. When this cell contributes the extra chromosome 13 to the embryo, trisomy 13 results. The extra chromosome 13 can come from either the mother’s egg cell or the father’s sperm cell. The abnormalities seen in babies with trisomy 13 result from having this extra chromosome 13 in each of the body’s cells. The incidence of this form of trisomy 13 is increased with maternal age.</p><p>Occasionally, the extra chromosome 13 is attached to another chromosome in the egg or sperm; this is called a translocation. This is the only form of trisomy 13 that can be inherited in a family. Sometimes, a parent can carry a “balanced” rearrangement where chromosome 13 is attached to another chromosome. However, since the parent does not have any extra or missing chromosome material, they are said to have a “balanced translocation” since they are normal and healthy.</p><p>Rarely, mosaic trisomy 13 may occur when the error in cell division occurs after fertilization. These babies have some cells with an extra chromosome 13 and others with the normal number. These cases usually have milder manifestations. </p><h2>Diagnosis of trisomy 13</h2><p>Babies with trisomy 13 have a unique group of characteristics and can be diagnosed by physical examination. To confirm the diagnosis, a small blood sample can be taken and the chromosomes can be analyzed to determine the presence of an extra chromosome 13.</p><p>Chromosomal abnormalities can also be diagnosed before birth by analyzing cells in the amniotic fluid obtained by <a href="/Article?contentid=342&language=English">amniocentesis</a>, or from the placenta, obtained by <a href="/Article?contentid=342&language=English">chorionic villus sampling (CVS)</a> or from the fetal blood obtained by cordocentesis. Screening for trisomy 13 is also available through first trimester screening (FTS), integrated prenatal screening (IPS) or by non-invasive prenatal testing (NIPT). The diagnosis of trisomy 13 can also be suggested by detailed <a href="/Article?contentid=342&language=English">fetal ultrasound</a>; however, ultrasound is not 100% accurate, since not all abnormalities can be seen on ultrasound and the same abnormalities seen prenatally in trisomy 13 can also be seen in other conditions. In contrast, a chromosome analysis, whether performed on fetal/newborn blood sample, cells from the amniotic fluid or placental sample, is over 99.9% accurate.</p>
Trisomie 13 (syndrome de Patau)TTrisomie 13 (syndrome de Patau)Trisomy 13 (Patau syndrome)FrenchGeneticsChild (0-12 years)BodyNAConditions and diseasesAdult (19+) CaregiversNA2016-07-19T04:00:00ZHealth (A-Z) - ConditionsHealth A-Z<p>Renseignements pour les parents au sujet de la trisomie 13, un trouble génétique rare qui cause des retards de développement et touche différents systèmes organiques.</p><h2>Qu’est-ce qu’une trisomie?</h2><p>Le terme trisomie (prononcez : tri-zo-mi) signifie que trois chromosomes sont présents plutôt que la paire habituelle de chromosomes. Par exemple, un bébé atteint du <a href="/Article?contentid=9&language=French">syndrome de Down</a> présente généralement trois exemplaires du chromosome 21 au lieu de la paire habituelle. Le trouble est ainsi nommé « trisomie 21 ».</p><h2>Qu’est-ce que la trisomie 13?</h2><p>La trisomie 13 est une anomalie chromosomique rare qui affecte approximativement une naissance sur 8 000 à 12 000. Les bébés atteints de trisomie 13 présentent plusieurs anomalies, touchant presque tous les systèmes organiques du corps, de même que des retards de développement. La trisomie 13 est aussi nommée syndrome de Patau, d’après le médecin qui a été le premier à décrire ce trouble.</p> <figure class="asset-c-80"><span class="asset-image-title">Caryotype du syndrome de Patau</span><img src="https://assets.aboutkidshealth.ca/akhassets/Trisomy_13_Patau_syndrome_MED_ILL_EN.jpg" alt="Les paires de chromosomes d’une femelle avec une copie supplémentaire du chromosome 13" /><figcaption class="asset-image-caption">Les personnes atteintes du syndrome de Patau présentent un exemplaire excédentaire du chromosome 13.</figcaption> </figure><h2>À retenir</h2><ul><li>La trisomie 13 est un trouble rare causé par un exemplaire excédentaire du chromosome 13.</li><li>Les bébés atteints de trisomie 13 présentent plusieurs anomalies, touchant presque tous les systèmes organiques du corps, de même que des retards de développement.</li><li>Il est difficile de prédire l’espérance de vie d’un bébé atteint de trisomie 13.</li><li>On suggère aux parents d’un bébé atteint de trisomie 13 de demander une consultation génétique.</li></ul><h2>Symptômes de la trisomie 13</h2><p>Les bébés atteints de trisomie 13 ont souvent un poids normal à la naissance, une petite tête et un front bombé. Leur nez est généralement large (« bulbeux »), la position des oreilles est basse et leur forme inhabituelle, les problèmes oculaires sont fréquents et un bec-de-lièvre, une fente palatine et des malformations cardiaques sont très communs. Plusieurs bébés atteints de trisomie 13 sont nés avec des petites zones sur le crâne où la peau est manquante (aplasie cutis), qui ressemblent à des ulcères.</p><p>Le cerveau des bébés porteurs de la trisomie 13 présente habituellement des problèmes majeurs de structure et, souvent, il ne se divise pas convenablement en deux hémisphères, ce qui aboutit à la maladie appelée holoproencéphalie. De nombreux bébés atteints de la trisomie 13 ont des doigts et des orteils surnuméraires (polydactylie). Certains se présentent avec une poche attachée à l’abdomen vers le cordon ombilical (omphalocèle), poche qui contient certains des viscères, et ils ont une <a href="/Article?contentid=371&language=French">spina bifida</a>. Les filles peuvent avoir un utérus avec une forme anormale, appelé utérus bicorne. Chez les garçons, les <a href="/Article?contentid=884&language=French">testicules parfois ne descendent pas dans le scrotu</a>m.</p><h2>Qu’est-ce qui cause la trisomie 13?</h2><p>Habituellement, chaque ovule et chaque spermatozoïde comprend 23 chromosomes. Au moment de la <a href="/Article?contentid=310&language=French">fécondation</a>, le spermatozoïde et l’ovule s’unissent et créent une cellule composée de 23 paires de chromosomes, soit 46 chromosomes. De cette façon, un enfant reçoit exactement la moitié de son matériel génétique de chacun de ses parents.</p><p>Parfois, une erreur se produit lors de la formation de l’ovule ou du spermatozoïde, entraînant la présence d’un chromosome excédentaire. Lorsque cette cellule donne un chromosome 13 excédentaire à l’embryon, il en résulte une trisomie 13. Le chromosome 13 excédentaire peut provenir de l’ovule de la mère ou du spermatozoïde du père. Les anomalies observées chez les bébés atteints de trisomie 13 sont le résultat de la présence de ce chromosome 13 excédentaire dans chacune des cellules du corps. L’incidence de cette forme de trisomie 13 augmente avec l’âge de la mère.</p><p>À l’occasion, le chromosome excédentaire 13 est attaché à un autre chromosome de l’ovule ou du spermatozoïde; on parle alors d’une translocation. Il s’agit de la seule forme de trisomie 13 pouvant être héréditaire dans une famille. Parfois, un parent peut être porteur d’un réarrangement « équilibré » où le chromosome 13 est attaché à un autre chromosome. Cependant, puisque le parent ne possède pas de matériel chromosomique excédentaire ou manquant, on dit qu’il présente une « translocation équilibrée » puisqu’il est normal et en santé.</p><p>En de rares occasions, une trisomie 13 mosaïque peut se produire quand l’erreur de division cellulaire survient après la fécondation. Certaines cellules de ces bébés possèdent un chromosome 13 excédentaire et d’autres ont le nombre habituel. Ces cas présentent habituellement une forme atténuée de la maladie.</p><h2>Diagnostic de la trisomie 13</h2><p>Les bébés atteints de trisomie 13 possèdent un ensemble unique de caractéristiques qui peuvent être diagnostiquées par un examen physique. Afin de confirmer un diagnostic, un petit échantillon de sang peut être prélevé et les chromosomes peuvent être analysés pour déterminer la présence d’un chromosome 13 excédentaire.</p><p>Les anomalies chromosomiques peuvent aussi être diagnostiquées avant la naissance en analysant les cellules contenues dans le liquide amniotique obtenues par <a href="/Article?contentid=342&language=French">amniocentèse</a>, par le placenta au moyen du <a href="/Article?contentid=342&language=French">prélèvement de villosités choriales (PVC</a>) ou à partir du sang fœtal obtenu par cordocentèse. Le dépistage de la trisomie 13 est aussi possible par le dépistage au premier trimestre (DPT), le dépistage prénatal intégré (DPI) ou le dépistage prénatal non invasif (DPNI). Le diagnostic de la trisomie 13 peut aussi être soupçonné par une <a href="/Article?contentid=342&language=French">échographie fœtale</a> détaillée; cependant, l’échographie n’est pas précise à 100 % puisque toutes les anomalies ne peuvent pas être détectées à l’échographie et les mêmes anomalies observées de manière prénatale dans le cas de la trisomie 13 peuvent aussi être observées dans d’autres troubles. Par ailleurs, une analyse chromosomique, qu’elle soit réalisée au moyen d’un échantillon sanguin, de cellules prélevées du liquide amniotique ou du placenta, est précise à plus de 99,9 %.</p>

 

 

 

 

Trisomy 13 (Patau syndrome)876.000000000000Trisomy 13 (Patau syndrome)Trisomy 13 (Patau syndrome)TEnglishGeneticsChild (0-12 years)BodyNAConditions and diseasesCaregivers Adult (19+)NA2016-07-19T04:00:00Z11.900000000000039.4000000000000995.000000000000Health (A-Z) - ConditionsHealth A-Z<p>Information for parents about trisomy 13, a rare genetic condition that causes developmental delay and affects many different organ systems.</p><h2>What is a trisomy?<br></h2><p>The term trisomy (say: TRY-so-mee) means that there are three chromosomes, rather than the usual pair of chromosomes. For example, a baby with <a href="/Article?contentid=9&language=English">Down syndrome</a> usually has three copies of chromosome 21, rather than the usual pair. The condition is thus called “trisomy 21.”</p><h2>What is trisomy 13?</h2><p>Trisomy 13 is a rare chromosome abnormality that affects approximately one in every 8,000 to 12,000 live births. Babies with trisomy 13 have many abnormalities, involving nearly every organ system in the body, as well as developmental delay. Trisomy 13 is also called Patau syndrome, after the physician who first described the disorder.</p> <figure class="asset-c-80"> <span class="asset-image-title">Patau syndrome karyotype</span> <img src="https://assets.aboutkidshealth.ca/akhassets/Trisomy_13_Patau_syndrome_MED_ILL_EN.jpg" alt="Pairs of chromosomes in a female with an extra copy of chromosome 13" /> <figcaption class="asset-image-caption">People with Patau syndrome have an extra copy of chromosome 13.</figcaption> </figure> <br><h2>Key points</h2> <ul> <li>Trisomy 13 is a rare condition caused by an extra copy of chromosome 13. </li> <li>Babies with trisomy 13 have many abnormalities, involving nearly every organ system in the body, as well as developmental delay. </li> <li>It is difficult to predict the life expectancy of a baby with trisomy 13. </li> <li>Parents of a baby with trisomy 13 are encouraged to seek genetic counselling.</li> </ul><h2>Signs and symptoms of trisomy 13</h2><p>Babies with trisomy 13 often have a normal birth weight, a small head and a sloping forehead. Noses are usually large (“bulbous”), ears are low-set and unusual in shape, eye defects occur frequently, and cleft lip and palate as well as heart defects are very common. Many babies with trisomy 13 are born with small areas of missing skin on the scalp (cutis aplasia), which resemble ulcers.</p><p>The <a href="https://pie.med.utoronto.ca/htbw/module.html?module=brain-child">brains</a> in babies with trisomy 13 usually have major structural problems and often, the brain does not divide properly into two hemispheres, resulting in a condition called holoprosencephaly. Many babies with trisomy 13 have extra fingers and toes (polydactyly). Some present with a sac attached to the abdomen in the area of the umbilical cord (omphalocele), which contains some of the abdominal organs, as well as <a href="/Article?contentid=371&language=English">spina bifida</a>. Girls may have an abnormally shaped uterus, called a bicornuate uterus. In boys, the <a href="/Article?contentid=884&language=English">testes sometimes fail to descend into the scrotum</a>.</p><h2>What causes trisomy 13?</h2><p>Usually each egg and sperm cell contains 23 chromosomes. At the time of <a href="/Article?contentid=310&language=English">fertilization</a>, the sperm and egg unite and create a cell with 23 chromosome pairs, or 46 chromosomes. In this manner, a child receives exactly half of their genetic material from each parent. </p><p>Sometimes, an error occurs when the egg or sperm cell is forming, causing it to have an extra chromosome. When this cell contributes the extra chromosome 13 to the embryo, trisomy 13 results. The extra chromosome 13 can come from either the mother’s egg cell or the father’s sperm cell. The abnormalities seen in babies with trisomy 13 result from having this extra chromosome 13 in each of the body’s cells. The incidence of this form of trisomy 13 is increased with maternal age.</p><p>Occasionally, the extra chromosome 13 is attached to another chromosome in the egg or sperm; this is called a translocation. This is the only form of trisomy 13 that can be inherited in a family. Sometimes, a parent can carry a “balanced” rearrangement where chromosome 13 is attached to another chromosome. However, since the parent does not have any extra or missing chromosome material, they are said to have a “balanced translocation” since they are normal and healthy.</p><p>Rarely, mosaic trisomy 13 may occur when the error in cell division occurs after fertilization. These babies have some cells with an extra chromosome 13 and others with the normal number. These cases usually have milder manifestations. </p><h2>Diagnosis of trisomy 13</h2><p>Babies with trisomy 13 have a unique group of characteristics and can be diagnosed by physical examination. To confirm the diagnosis, a small blood sample can be taken and the chromosomes can be analyzed to determine the presence of an extra chromosome 13.</p><p>Chromosomal abnormalities can also be diagnosed before birth by analyzing cells in the amniotic fluid obtained by <a href="/Article?contentid=342&language=English">amniocentesis</a>, or from the placenta, obtained by <a href="/Article?contentid=342&language=English">chorionic villus sampling (CVS)</a> or from the fetal blood obtained by cordocentesis. Screening for trisomy 13 is also available through first trimester screening (FTS), integrated prenatal screening (IPS) or by non-invasive prenatal testing (NIPT). The diagnosis of trisomy 13 can also be suggested by detailed <a href="/Article?contentid=342&language=English">fetal ultrasound</a>; however, ultrasound is not 100% accurate, since not all abnormalities can be seen on ultrasound and the same abnormalities seen prenatally in trisomy 13 can also be seen in other conditions. In contrast, a chromosome analysis, whether performed on fetal/newborn blood sample, cells from the amniotic fluid or placental sample, is over 99.9% accurate.</p><h2>Life expectancy of a baby with trisomy 13</h2><p>Fifty per cent of babies born with trisomy 13 survive beyond their first 7.5 to 12.5 days. About 20% of babies born with trisomy 13 survive the first year of life. It is difficult to predict the life expectancy of a baby with trisomy 13 if the baby does not have any immediate life-threatening problems. For babies that have survived their first 30 days of life, 47% were alive at one year. About 13% of children born with trisomy 13 survive until 10 years of age.</p> <h2>There is a small chance of having another child with trisomy 13</h2><p>The risk of having a baby with trisomy 13 increases slightly with the mother’s age. However, the average age of the mother at delivery of a baby with trisomy 13 is 32 years. In general, in each subsequent <a href="/Article?contentid=316&language=English">pregnancy</a>, the chance of having another baby with trisomy 13 is no greater than 1%. </p><h2>Genetic counselling is recommended</h2><p>Parents of a baby with trisomy 13 are encouraged to seek <a href="/Article?contentid=343&language=English">genetic counselling</a>. This can help parents to:</p><ul><li>understand the results of chromosomal tests in detail</li><li>understand the chances that other babies will be affected</li><li>understand the diagnosis options for future pregnancies</li></ul>https://assets.aboutkidshealth.ca/akhassets/Trisomy_13_Patau_syndrome_MED_ILL_EN.jpgTrisomy 13 (Patau syndrome)False

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