Translocation trisomy For parents of a child with Down syndrome due to a translocation, there may be an increased chance of Down syndrome in future pregnancies. This is because one of the two parents may be a carrier of a balanced translocation. However, not all parents of people with translocation trisomy 21 have a translocation. Regardless of the type of Down syndrome a person has, all people with Down syndrome have an extra, critical portion of chromosome 21 present in all or some of their cells.
This extra genetic material disrupts the normal course of development, causing the characteristic features of Down syndrome. Diagnosis Diagnosis. During pregnancy, a woman can opt to have specific tests that may either screen for, or diagnosis, Down syndrome in a fetus. A screening test poses no risks to the fetus and can determine the likelihood that a fetus has Down syndrome.
It may show that a fetus is at an increased risk to be affected, but cannot determine whether it is definitely affected. Depending on the type of screening tests a woman has, they may be done during the 1st trimester, the 2nd trimester, or both. If a screening test shows an increased risk for Down syndrome, a woman may then choose to have a diagnostic test. Examples of diagnostic tests include chorionic villus sampling in the 1st trimester and amniocentesis in the 2nd trimester.
During these tests, a small sample of genetic material is obtained from the amniotic fluid or placenta, and the fetus' chromosomes are then analyzed in a laboratory. However, women who have a positive NIPT result should then have invasive diagnostic testing to confirm the result.
People with questions about the different options for prenatal screening or diagnostic testing should speak with a genetic counselor.
A genetic counselor can discuss the benefits, limitations and risks of each test, and help each person decide which test if any is best for them.
If a diagnosis of Down syndrome is not made prenatally, the diagnosis can be made in the newborn. Down syndrome may be suspected if a newborn has characteristic physical features of the condition. The diagnosis can then be confirmed by obtaining a karyotype a blood test to look at a picture of the newborn's chromosomes. Treatment Treatment.
Early intervention services , quality educational programs, a stimulating home environment, good health care, and positive support from family and friends can help people with Down syndrome develop to their full potential.
The Research Down syndrome Foundation have a webpage with information about active reseach projects. Committee on Genetics. J Pediatr Health Care. Find a Specialist Find a Specialist. Healthcare Resources To find a medical professional who specializes in genetics, you can ask your doctor for a referral or you can search for one yourself.
You can also learn more about genetic consultations from MedlinePlus Genetics. Related Diseases Related Diseases. Conditions with similar signs and symptoms from Orphanet. Differential diagnosis includes Zellweger syndrome, 9qter deletion or other chromosomal abnormalities. Visit the Orphanet disease page for more information. Research Research. Clinical Research Resources ClinicalTrials. Click on the link to go to ClinicalTrials.
Please note: Studies listed on the ClinicalTrials. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study. Patient Registry A registry supports research by collecting of information about patients that share something in common, such as being diagnosed with Down syndrome.
The type of data collected can vary from registry to registry and is based on the goals and purpose of that registry. Some registries collect contact information while others collect more detailed medical information. Learn more about registries. Organizations Organizations. Organizations Supporting this Disease. Association for Children with Down Syndrome, Inc. Do you know of an organization? Living With Living With. Their Web site offers general and condition-specific education resources to help teachers and parents better understand the needs of students who have genetic conditions.
Learn More Learn More. Click on the link to view information on this topic. March of Dimes has a factsheet on Down syndrome. MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic. This website is maintained by the National Library of Medicine. The Merck Manual provides information on this condition for patients and caregivers. A Positive Exposure program called FRAME has an educational film about Down syndrome that was created to change how medical information is presented to healthcare professionals.
Positive Exposure is an organization that uses photography, film, and narrative to transform public perceptions of people living with genetic, physical, intellectual, and behavioral differences.
In-Depth Information Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free. Each entry has a summary of related medical articles.
It is meant for health care professionals and researchers. Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
PubMed is a searchable database of medical literature and lists journal articles that discuss Down syndrome. Click on the link to view a sample search on this topic. Have a question? References References. Down syndrome. Genetics Home Reference Web site. Chen H. Down Syndrome. Medscape Reference. Complete trisomy In this case, an error during the formation of the egg or the sperm results in either one having an extra chromosome. So after the egg and sperm unite, the resulting cells will also have three copies of chromosome The complete extra copy of chromosome 21 is in all of the person's cells—or a complete trisomy.
Almost all Down syndrome cases result from complete trisomy Not every cell in the body is exactly the same. This is called "mosaicism. Messerlian GM, et al. Down syndrome: Overview of prenatal screening. National Library of Medicine. Down syndrome. Genetics Home Reference. Facts about Down syndrome. Centers for Disease Control and Prevention. Frequently asked questions. Prenatal genetic diagnostic tests. American College of Obstetricians and Gynecologists.
Ostermaier KK. Down syndrome: Management. Down syndrome: Clinical features and diagnosis. Accessed Jan. Gabbe SG, et al. Genetic screening and prenatal genetic diagnosis. In: Obstetrics: Normal and Problem Pregnancies. Philadelphia, Pa. Rink BD, et al. Screening for fetal aneuploidy. Both mitosis and meiosis involve the ordered distribution of chromosomes to form daughter cells. If non-disjunction occurs, it can result in individuals having an abnormal number of chromosomes for example, three copies of chromosome 21 in their cells.
Translocation: One copy of chromosome 21 becomes attached to another chromosome and is inherited as a passenger on that other chromosome. People with Down's syndrome can live into their 40s and 50s. Related Content:. What is a genetic disorder? What is a chromosome disorder? What is a chromosome?
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