Mosaic trisomy 15

Mosaic trisomy 15 is usually new to the person who has it, meaning that neither parent has mosaic trisomy 15. If this is the case, it is most likely not necessary to test other family members. However, it may be necessary to test the parents to see if they have a chromosome change called a translocation that makes it more likely for their children to have this disorder. Check with your healthcare team if you have additional questions about who in your family should be tested.

Start by checking with your healthcare team for resources in your area. You can also join an online support group. There are multiple online support group for people with different types of trisomies. One such group is called Trisomy Online and can be found at: http://www.trisomyonline.org/families.htm.

Other helpful groups are:

People with mosaic trisomy 15 can see a medical genetics team. These healthcare providers specialize in genetic disorders and will be able to evaluate and address all of the individual needs of someone with mosaic trisomy 15. They may refer people with mosaic trisomy 15 to specialists depending on their individual symptoms. For example, newborns may see a surgeon if they need to have a heart problem fixed.

The most common abbreviation for this disorder is Mosaic Ts15.

In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46 chromosomes. Each pair is numbered 1 through 22 except for the sex chromosomes which are denoted by "X" and "Y." Women have two Xs while men have one X chromosome and a Y chromosome. In complete trisomy 15, ALL of the cells of the body have an extra chromosome 15, which means that there are 47 chromosomes in all the cells. A fetus with an extra chromosome 15 in all its cells will usually miscarry and not make it to term. In MOSAIC trisomy 15, only some of the cells of the body have an extra chromosome 15, which means that there are 47 chromosomes in those cells while the other cells in the body have the typical 46 chromosomes. The cells with the extra chromosome 15s are called "trisomic," as they have a third chromosome 15. The word "mosaic" means that only some cells in the body have the extra chromosome while others do not. An extra chromosome 15 in some of the body’s cells causes a range of symptoms, including specific facial features, being small in the womb, and heart problems. Everyone with mosaic trisomy 15 will have a different set of symptoms because they will have a different number of trisomic cells and those cells will be in different parts of the body.

When mosaic trisomy 15 is found before a baby is born, through amniocentesis or chorionic villus sampling, it can be very difficult to predict what health problems will occur. If the test finding mosaic trisomy 15 is a chorionic villus sampling, then there is a chance that all the trisomy 15 cells are only in the placenta and not in the baby (confined placenta mosaicism). In this case, an amniocentesis may be suggested to look at the baby’s cells directly. If the cells with extra chromosome 15 are in the baby and the placenta, usually the baby’s health is predicted based upon the percent of cells that have the extra chromosome 15, if the extra chromosome is from mom or dad, and the number of health problems or birth defects seen on ultrasound. Medical geneticists and genetic counselors can be very helpful in discussing the possible outcomes based on this information.

Most often infants with many cells that have the extra chromosome 15 are very sick and die early in life; however, individuals with fewer trisomic cells have fewer health issues and may live longer. Rarely, individuals with a very small number of trisomic cells found on prenatal testing can have very few to no medical issues and live a normal life span.

Unfortunately, the symptoms of mosaic trisomy 15 are usually severe. At birth, babies may have problems with the heart, along with other organ systems.

When mosaic trisomy 15 is found before a baby is born, through amniocentesis or chorionic villus sampling, it can be very difficult to predict what health problems will occur. If the test finding mosaic trisomy 15 is a chorionic villus sampling, then there is a chance that all the trisomy 15 cells are only in the placenta and not in the baby (confined placenta mosaicism). In this case, an amniocentesis may be suggested to look at the baby’s cells directly. If the cells with extra chromosome 15 are in the baby and the placenta, usually the baby’s health is predicted based upon the percent of cells that have the extra chromosome 15, if the extra chromosome is from mom or dad, and the number of health problems or birth defects seen on ultrasound. Medical geneticists and genetic counselors can be very helpful in discussing the possible outcomes based on this information.

Most often infants with many cells that have the extra chromosome 15 are very sick and die early in life; however, individuals with fewer trisomic cells have fewer health issues and may live longer. Rarely, individuals with a very small number of trisomic cells found on prenatal testing can have few to no medical issues and live a normal life span.

To find a genetic professional near you who can discuss genetic testing, visit the following two sites: A listing of medical geneticists can be found at the American College of Medical Geneticists website ([link url="” target=”_blank”>www.acmg.net) and genetic counselors can be found on the National Society of Genetic Counselors website: [link url="” target=”_blank”>www.nsgc.org.

Scientists and doctors are not sure exactly how having an extra chromosome can cause the symptoms of mosaic trisomy 15. Chromosomes contain DNA, which is the set of instructions telling the body how to grow, develop and function. In mosaic trisomy 15, the extra set of instructions that are in some cells because of the extra copy of chromosome 15 appears to interfere with typical development.

The word "mosaic" means that only some cells have the extra chromosome while others do not. An extra chromosome 15 causes a range of symptoms, including specific facial features, being small in the womb, and heart problems. Everyone with mosaic trisomy 15 can have a different set of symptoms because they may have a different number of trisomic cells (those with the extra chromosome 15), and the trisomic cells may be in different parts of the body.

Humans normally have 23 pairs of chromosomes for a total of 46 chromosomes. Each pair is numbered 1 through 22 except for the sex chromosomes which are denoted by "X" and "Y." Women have two Xs while men have one X and Y. In mosaic trisomy 15, some of the cells of the body have an extra chromosome 15, which means that there are 47 chromosomes in those cells. The word "mosaic" means that only some cells have the extra chromosome while others do not. This extra chromosome causes the symptoms of mosaic trisomy 15.

Mosaic trisomy 15 usually happens because of a random change in either the sperm or egg. That change causes the egg or sperm to have an extra chromosome. Usually, the change is new to the child, meaning that neither parent has mosaic trisomy 15. However, it is possible for a chromosome change in a parent (called a translocation) to make it more likely that a child will have mosaic trisomy 15.

People with mosaic trisomy 15 can have many different symptoms, including changes to growth. Babies with mosaic trisomy 15 are often small before birth, which is sometimes called intrauterine growth retardation (IUGR). Other symptoms include problems with the heart, specific facial features, and trouble with other organs. Everyone with mosaic trisomy 15 can have a different set of symptoms because they may have a different number of trisomic cells, and the trisomic cells may occur in different parts of the body.

There is complete penetrance with mosaic trisomy 15. This means that everyone who has an extra chromosome 15 in some of their cells has the disorder. It is possible, however, that people with mosaic trisomy 15 will have different features from one another (variable expression). This is because different people with mosaic trisomy 15 may have a different number of trisomic cells, and the trisomic cells may be in different parts of the body.

When mosaic trisomy 15 is found before a baby is born, through amniocentesis or chorionic villus sampling, it can be very difficult to predict what health problems will occur. If the test finding mosaic trisomy 15 is a chorionic villus sampling, then there is a chance that all the trisomy 15 cells are only in the placenta and not in the baby (confined placenta mosaicism). In this case, an amniocentesis may be suggested to look at the baby’s cells directly. If the cells with extra chromosome 15 are in the baby and the placenta, usually the baby’s health is predicted based upon the percent of cells that have the extra chromosome 15, if the extra chromosome is from mom or dad, and the number of health problems or birth defects seen on ultrasound. Medical geneticists and genetic counselors can be very helpful in discussing the possible outcomes based on this information.

There is not one symptom that is characteristic of mosaic trisomy 15. Most commonly, babies with the condition will be small in the womb (IUGR) and have a heart defect.

Mosaic trisomy 15 is not included on newborn screening. However, if mosaic trisomy 15 is suspected, the medical team can order a chromosomal analysis through karyotype or microarray. This is a picture of the chromosomes, which are instructions for the body. It allows your healthcare team to see if there is an extra chromosome 15 in some of the cells of the body.

The main test to diagnosis mosaic trisomy 15 is chromosome analysis using karyotype, or picture of the chromosomes. The karyotype allows your healthcare team to see if there is an extra chromosome 15 in some of the cells of the body. An extra trisomy 15 chromosome can also be detected on a test called a chromosomal microarray analysis, which searches for extra or missing chromosomes and chromosome pieces. Your healthcare team may also suggest uniparental disomy testing, or UPD testing to determine if the extra chromosome is from mom or dad as that can lead to other genetic conditions such as Prader-Willi syndrome or Angelman syndrome. These tests are performed using a sample of cells from the placenta (chorionic villus samplic) or amniotic fluid (amniocentesis) during pregnancy, or from a blood sample after birth. If mosaic trisomy 15 is diagnosed by any of these methods, the doctors may perform other tests to look for symptoms that may have been missed. For example, they may want to look at the heart to be sure there are no problems.

Mosaic trisomy 15 is a very rare condition, and as of February 2016 there was no clinical research available for mosaic trisomy 15. To check if a study is currently going on for this disorder, go to [link url="clinicaltrials.gov” target=”_blank”>clinicaltrials.gov and search for mosaic trisomy 15.

Mosaic trisomy 15 is a very rare condition that can occur randomly in any pregnancy; however, there is a slightly higher chance of it occurring in pregnancies of women over age 35 and in pregnancies achieved through in vitro fertilization (IVF).

There is no cure for mosaic trisomy 15. However, there are treatments for the individual symptoms of mosaic trisomy 15. For example, surgery may be needed at birth to repair problems with the heart.

Having an extra copy of chromosome 15 in some, but not all, cells of the body causes mosaic trisomy 15. Mosaic trisomy 15 usually happens because of a random change in either the sperm or egg. That change causes the egg or sperm to have an extra chromosome. Usually, the change is new to the child, meaning that neither parent has mosaic trisomy 15 and there is no other family history of the condition. However, it is possible for a chromosome change in a parent (called a translocation) to make it more likely that a child will have mosaic trisomy 15.

Trisomy usually happens because the sperm or egg has an extra chromosome. When they combine, they make a cell (which will become a baby) with 47 chromosomes. Mosaicism (where some cells of the body are different from others-there are at least two cell types) occurs when the extra chromosome is not passed on to all the cells created from the original cell; hence, the baby has some cells that have a trisomy with 47 chromosomes and some cells that are normal with 46 chromosomes. The extra chromosome is "lost" as the body’s cells are made or replicated.

There are also other, less common, causes such as an inherited chromosomal translocation, or a chromosome change in one of the parents that predisposes to mosaic trisomy 15.

Your doctor should be knowledgeable about the symptoms of mosaic trisomy 15 and that different children will have different health issues.

If both parents have normal chromosomes with no rearrangements or extra chromsomes, then the chances are low that a second child will have mosaic trisomy 15. Usually, mosaic trisomy 15 is caused by a chromosomal change that is random and new to the child. This means that neither parent has the extra copy of chromosome 15, and the chances are low that the same change will happen in another pregnancy. There are some exceptions to this, so be sure to check with your medical team or a genetic counselor for your personalized risk.

It is hard to predict exactly how long someone with mosaic trisomy 15 will live. Most often infants with many cells that have the extra chromosome 15 disorder are very sick and many die early in life. However, individuals with fewer cells with the extra chromosome 15 tend to have fewer health issues and may live longer. Rarely, individuals with a very small number of cells with an extra chromosome 15 found on prenatal testing may have very few to no medical issues and live a normal life span.

When mosaic trisomy 15 is found before a baby is born, through amniocentesis or chorionic villus sampling, it can be very difficult to predict what health problems will occur. If the test finding mosaic trisomy 15 is a chorionic villus sampling, then there is a chance that all the trisomy 15 cells are only in the placenta and not in the baby (confined placenta mosaicism). In this case, an amniocentesis may be suggested to look at the baby’s cells directly. If the cells with the extra chromosome 15 are in the baby and the placenta, usually the baby’s health is predicted based upon the percent of cells that have the extra chromosome 15, if the extra chromosome is from mom or dad, and the number of health problems or birth defects seen on ultrasound. Medical geneticists and genetic counselors can be very helpful in discussing the possible outcomes based on this information.

Chromosomal mosaicism, where some cells of the body have a different number of chromosomes from other cells, usually happens because of a random change in either the sperm or egg. That change causes the egg or sperm to have an extra chromosome. Usually, the change is new to the child, meaning that neither parent has mosaic trisomy 15. However, it is possible for a chromosome change in a parent (called a translocation) to make it more likely that a child will have mosaic trisomy 15.

If mosaic trisomy 15 is suspected, a sample of the DNA from the developing fetus is needed to diagnose the disorder. Fetal DNA can be found in the placenta or in the amniotic fluid (the liquid surrounding the fetus in the womb). Before 14 weeks of gestation, the placenta can be sampled through chorionic villus sampling (CVS). During this procedure, the doctor inserts an instrument through the vagina or through the mother’s abdomen to obtain the sample. After 14 weeks, the amniotic fluid can be sampled by inserting a needle through the mother’s abdomen.

When mosaic trisomy 15 is found before a baby is born, through amniocentesis or chorionic villus sampling, it can be very difficult to predict what health problems will occur. If the test finding mosaic trisomy 15 is a chorionic villus sampling, then there is a chance that all the trisomy 15 cells are only in the placenta and not in the baby (confined placenta mosaicism). In this case, an amniocentesis may be suggested to look at the baby’s cells directly. If the cells with extra chromosome 15 are in the baby and the placenta, usually the baby’s health is predicted based upon the percent of cells that have the extra chromosome 15, if the extra chromosome is from mom or dad, and the number of health problems or birth defects seen on ultrasound. Medical geneticists and genetic counselors can be very helpful in discussing the possible outcomes based on this information.

It may be difficult to find ways to donate to mosaic trisomy 15 research specifically because it is a rare condition. It is possible to donate to organizations that focus on chromosome abnormalities or NORD, which is an organization that supports research in a variety of less common diseases. Here are some options:

The test used to diagnose mosaic trisomy 15 is called a karyotype. This is a way to see and count the number of chromosomes in the cells of the body. Chromosomes contain DNA and provide the instructions for the body on how to grow and function. Mosaic trisomy 15 is caused by an extra chromosome 15 in some cells of the body. By looking at a karyotype, your healthcare team is able to see if there is an extra chromosome 15 in some of the cells of the body. An extra 15 chromosome can also be detected on a test called a chromosomal microarray analysis which searches for extra or missing chromosomes and chromosome pieces.

Your healthcare team may also suggest an additional test called uniparental disomy testing, or UPD testing. Seeing an extra copy of chromosome 15 in some cells (mosaic trisomy 15) sometimes means that there was an extra copy of chromosome 15 in other cells that then disappeared. These cells will look normal on a karyotype (two copies of chromosome 15), but the two copies could be from the same parent. Having two copies of chromosome 15 from the same parent causes other genetic conditions such as Prader-Willi syndrome or Angelman syndrome. So, when trisomy 15 is seen on a karyotype, your doctor may also want to do UPD testing to see if both copies of chromosome 15 in the non-trisomic cells were inherited from the same parent.

It is also possible that some symptoms are seen on an ultrasound before birth, which will make the healthcare team suspect that the child has mosaic trisomy 15.

Since this is a rare disorder, it may be difficult to find research in mosaic trisomy 15 specifically. To find current studies, go to [link url="clinicaltrials.gov” target=”_blank”>clinicaltrials.gov and search for mosaic trisomy 15.

If you are pregnant with a child that has mosaic trisomy 15, you may be referred to a maternal fetal medicine doctor (MFM). These doctors specialize in pregnancies that require special care and attention. They often work with a genetic counselor who can help you understand mosaic trisomy 15 and find resources.

If a child with mosaic trisomy 15 is live born, a referral to a medical genetics clinic may be made. A medical geneticist and pediatric genetic counselor can help you understand and address your child’s specific needs. You may also want to seek out clinics that specialize in caring for the specific symptoms. For example, if a child has a heart defect, they may need to see a pediatric or adult cardiologist. If a child has severe health problems, a pediatric hospice team may also be helpful for the whole family.

Trisomy 15 and mosaic trisomy 15 is most often found during prenatal testing through chorionic villus sampling (CVS). In one study, most trisomy 15 seen before birth via CVS was found through additional testing to only be present in the placenta (confined placental mosaicism), which doesn’t affect the baby. However, there was 1 baby with true mosaic trisomy 15. This tell us that true mosaic trisomy 15 in a fetus is quite rare. In the past 20 years, only approximately 20 people with this disorder have been written about in the scientific community, although internet support groups have helped people find each other and learn more about having mosaic trisomy 15.

Some of these online communities include:

If a child with mosaic trisomy 15 has a congenital heart defect, or a problem with the heart at birth, (s)he may or may not require surgery. Sometimes, only one procedure is needed. Other times, multiple surgeries and medication may be necessary. The treatment depends on the specific defect. If your child with mosaic trisomy 15 has a congenital heart defect, you should work with a medical geneticist and pediatric cardiologist to understand your child’s specific needs and to make a plan.

Usually, chromosome testing is done on the blood. If testing is being done prenatally, it may be done through chorionic villus sampling or via amniocentesis.

The more cells that have an extra chromosome 15 in the body, the more severe the medical problems are expected to be, however, there is no way to control how many cells in the body, or which cells in the body, will have the extra chromosome 15. Otherwise, there is nothing that makes the symptoms of mosaic trisomy 15 worse.

Some of the symptoms of mosaic trisomy 15 can be treated. For example, surgery may be needed at birth to repair problems with the heart. Other symptoms can be treated as necessary.

It can also be called chromosome 15, trisomy mosaicism.

There are multiple online support group for people with different types of trisomies. One such group is called Trisomy Online and can be found at:http://www.trisomyonline.org/families.htm

Other helpful groups are:

All forms of mosaic trisomy 15 are genetic. Everyone with mosaic trisomy 15 has an extra chromosome 15 in some cells of the body.

There are no other forms of mosaic trisomy 15. However, people with this disorder can have different symptoms from each other because they may have a different number of trisomic cells in the body, and these trisomic cells may be in different parts of the body.

There are many genetic diseases with similar symptoms to mosaic trisomy 15, including other more common chromosome conditions, like trisomy 18 (Edwards syndrome). Mosaic trisomy 15 should be confirmed with genetic testing.