Usually, this is done by a genetic counselor trying to determine if the person has a genetic abnormality. This is one of the most common causes of mental deficiencies. Trisomy 9, believed to be the 4th most common trisomy, has many long lived affected individuals but only in a form other than a full trisomy, such as trisomy 9p syndrome or mosaic trisomy 9. The third leads to a translocation down syndrome child. Click on karyotyping under human biology and read the introduction page. Discuss chromosomes as a means of organising dna and how genetic disease can be caused through incorrect numbers of chromosomes e. The human male determines the sex of all of his offspring. Transcription disorders disorders with meiosis monosomies and trisomies how to construct karyotype charts spotting disorders with karyotype charts down, turner, klinefelter, edward, patau, triplox and jacobs disorders. Students then diagnose the chromosomal aneuploidy based on the karyotype, list the symptoms associated with the disorder, and discuss the implications of the diagnosis. After a positive screening, women are offered prenatal foetus karyotyping, the gold standard. If the karyotype is abnormal, circle the abnormality in the karyotype. Then explain what is wrong with the karyotype, and where the abnormality is located specifically on the chromosome.
Chromosome analysis national human genome research. Its characterized by a variety of distinctive physical features, an increased risk of certain medical problems, and varying degrees of developmental and intellectual delays. Karyotyping activity with case histories from the university of arizonas biology project. This important model can be broken down into four main ideas. Start studying karyotyping and down s syndrome lc 1. This excess genetic material, in the form of additional genes along chromosome 21, results in down syndrome. The incidence of this syndrome is 1100,000 live births. This product offered by spyglass biology contains a single worksheet about disorders caused by nondisjunction as well as reading karyotypes to identify the disorders. This classroom activity is based on a constructivist learning design and engages students in physically constructing a karyotype of three mock patients.
Combination of water and land exercise is an effective strategy to improve daily activities in down syndrome children. The second, combined with a normal gamete from the other parent, gives rise to a typical child. It was later determined that an extra partial or complete chromosome 21 results in the characteristics associated with down syndrome. Sep 30, 2015 the students can then take that information and research it online or at a library to find the syndrome s name and symptoms long answer set. Disorder name description of disorder subject circle c, d, or e symptoms list 12 from diagnosis down syndrome extra chromosome 21 c d e klinefelter syndrome extra x in male xxy c d e turner. A karyotype test can be performed in several ways, and can be done during. What notation would you used to characterize pacient as karyotype. You will be arranging chromosomes into a completed karyotype, and interpreting your findings just as if you were working in a genetic analysis program at a hospital or clinic. Testing for down syndrome is offered as a part of routine antenatal care for women in most developed nations, and has been increasingly introduced in developing countries. These guidelines are designed to assist the pediatrician in caring for the child in whom the diagnosis of down syndrome has been confirmed by karyotype. A picture of all the chromosomes in a cell arranged in pairs. It was noted that combination of exercise and aqua therapy showed significant improvement in many motor parameters in downs syndrome children. While the karyotype of a typical person shows 23 pairs of chromosomes for a total of 46, the karyotype of a person with down syndrome shows an additional 21st chromosome, resulting in a total number of 47. The 5 disorders are down syndrome, klinefelters, xyy syndrome, turners syndrome, and trisomy x.
To obtain a karyotype, doctors draw blood and photograph the. Health supervision for children with down syndrome american. Then have students cut out and complete the karyotype ensure there is a mixture of the three patient karyotypes across the class. Karyotype karyotype of a person with down syndrome the chromosomal basis of down syndrome to understand why down syndrome occurs, the structure and function of the human chromosome must be understood. This exercise is a simulation of human karyotyping using digital images of chromosomes from actual human genetic studies. Reliable molecular methods for rapid aneuploidy diagnosis. How do two physically healthy parents produce a child with down syndrome and a second child with cri du chat syndrome. A case of down syndrome with 45 chromosomes was presented. Choose from 500 different sets of karyotype flashcards on quizlet. Karyotype analysis of human chromosome easybiologyclass. When finished, use the print screen option to copy your karyotype into a word processing document or image editor. Down syndrome is a chromosomal abnormality characterized by the presence of an extra copy of genetic material on chromosome 21, either in whole trisomy 21 or part such as due to translocations.
Such changes, primarily the result of nondisjunction or translocation, are so severe that the pregnancy ends in miscarriage or fertilization does not occur at all. It is usually associated with physical growth delays, mild to moderate intellectual disability, and characteristic facial features. Diagnosing chromosome disorders, haspi medical biology lab 17 names. Down syndrome is a chromosomal condition that is associated with intellectual disability, a characteristic facial appearance, and weak muscle tone hypotonia in infancy. Although women of any age can have a child with down syndrome, the chance of having a child with this condition increases as a woman gets older. Karyotype analysis activity the american biology teacher. Syndrome trisomy 21 is a genetic disorder caused by the presence of an extra 21st chromosome.
One way to determine the underlying cause of a syndrome with a genetic basis is to produce a karyotype and then look for chromosomal abnormalities that may explain it. These syndromes therefore may have a genetic basis. Print the three patient karyotypes attached as a pdf. Karyotype of the propositus was determined as 45, xy. Trisomy 21 is a prototypical genetic condition in which characteristic facial features fig. The website was created by university of arizonas biology project and provides the opportunities to create and analyse chromosomes while creating a karyotype. Karyotyping requests for a clinical diagnosis of down syndrome were also identified. Down syndrome can be diagnosed by physical features in most cases, and is confirmed by a karyotype usually done on a blood sample. The students worksheets are five pages long since they include an introduction in each set. What type of cell samples are used for karyotyping. This ordering and pairing of chromosomes is called a karyotype. Down syndrome, a common chromosomal disease, is caused by trisomy of chromosome 21. This activity is perfect for group and whole class discussion.
Trisomy 21 down syndrome is the most common cause of genetic mental retardation, occurring in one in 700 live births. Use guided inquiry to analyze 7 human karyotypes and match with descriptions on a chart. Accuracy of the clinical diagnosis of down syndrome. Analysis of a normal karyotype observe the karyotype below. Although the pediatricians initial contact with the child is usually during infancy, occasionally the pregnant woman who has been given the prenatal diagnosis of down syndrome will be referred for counseling. The last becomes a translocation carrier, like the parent. Mosaic down syndrome is a rare, less severe form of down syndrome. Ninth grade lesson creating karyotypes betterlesson. Down syndrome is correlated with age of mother but can also be the result of nondisjunction of the fathers chromosome 21.
In this activity, you will use a computer model to look at chromosomes and prepare a karyotype. With advanced medical treatments, the average life span of an individual with down syndrome is now about 50 years. Down syndrome is the most common chromosome abnormality in humans. It occurs in about one per 1,000 babies born each year. Individuals who have down syndrome have unique facial features and physical features, certain medical findings such as heart defects, gastrointestinal problems, etc. Rapid testing versus karyotyping in downs syndrome. All affected individuals experience cognitive delays, but the intellectual disability is usually mild to moderate. The test results can show whether or not your baby has down syndrome, trisomy, trisomy 18, or other genetic problems.
Learn vocabulary, terms, and more with flashcards, games, and other study tools. In individuals with down syndrome, however, the cells usually contain 47, not 46, chromosomes. A karyotype is a picture of chromosomes that have been organized in homologous pairs from. Next to each karyotype, identify it as either normal or abnormal. About 5,300 babies with down syndrome are born in the united states each year, and approximately 200,000 people in this country have the condition. The effects of the extra copy varies greatly from individual to individual, depending on the extent of the extra copy, genetic background, environmental factors, and random chance. Down syndrome with 45 chromosomes journal of human genetics. Analysis questions 1 how many autosomes any chromosome that that is not a sex chromosome are in a normal human karyotype. Individuals with down syndrome are more likely to survive through birth and beyond as compared to other trisomy disorders. This is the fifth report of down syndrome with 45 chromosomes. In this lesson, students will analyze the effect of environmental and hereditary factors on fetal development, including prenatal brain development. People with down syndrome may have a variety of birth defects. Down syndrome, also known as trisomy 21, is a genetic disorder that occurs when a person has a full or partial extra copy of chromosome 21. Student work ol karyotype activity the university of arizonas biology project provides an amazing activity for students to work with real data to reinforce the content of todays.
Chromosome analysis national dna day april 25, 2005. Occasionally chromosomal material is lost or rearranged during the formation of gametes or during cell division of the early embryo. These features may be present in babies who do not have down syndrome, so a karyotype chromosomal analysis is done to make a diagnosis. How does subject cs karyotype differ from a normal karyotype. The 5 disorders are down syndrome, klinefelters, xyy syndrome, turners syndrome, and. Instead of the usual 46 chromosomes present in each cell, lejeune observed 47 in the cells of individuals with down syndrome. Rapid testing versus karyotyping in downs syndrome screening. Trisomy 21 down syndrome z individuals with down syndrome have a typical facial appearance z all have some degree of mental retardation, but for most it is mild or moderate z can learn to read, write, do some math, and live daytoday with minimal assistance from others z others require a lot of attention and care z. Trisomy 21, commonly referred to as down syndrome, is caused by an additional copy of the 21st chromosome that typically results from a nondisjunction event during gametogenesis. Translocation down syndrome is often referred to as familial down syndrome. A lab technician can create a karyotype by collecting a sample of cells from an individual.
Start studying karyotyping and downs syndrome lc 1. Down syndrome ds or dns, also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. This activity is targeted at undergraduates in a nonmajors genetics course. We explain the condition, its cause, symptoms, and how to diagnose it. You will diagnose patients for abnormalities and learn the correct notation for characterizing karyotypes. Karyotype curiosities determining different karyotypes when geneticists want to look at a persons chromosomes, they make a karyotype. Karyotype and idiogram ppt karyotype, idiogram and its significance ppt what is karyotype. What notation would you used to characterize pacient bs karyotype. A down syndrome karyotype is a genetic screening tool that identifies the presence of a chromosome 21 abnormality. Introduction mendels model of inheritance is the basis for modern genetics. Down syndrome is usually identified at birth by physical traits. The students can then take that information and research it online or at a library to find the syndromes name and symptoms long answer set. Age of diagnosis was determined using date of receipt.
The purpose of karyotype analysis is to look at the gross anatomical structures of the chromosomes of an individual. What notation would you used to characterize pacient cs karyotype. The karyotype activity consists of two sets of chr omosomes, mom s chromosomal contribution and dads chromosomal contribution. Genesis, a database located in the department of medical genetics, was used to identify the number of down syndrome karyotypes including trisomy, translocation, and mosaic sample variants. In all, 80% of antenatal karyotypes are generated by downs syndrome screening programmes dssp. Feb 04, 2019 down syndrome ds or dns, also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. The extra 21st chromosome is detected by using a procedure called a karyotype. Karyotyping activity this exercise is a simulation of human karyotyping using digital images of chromosomes from actual human genetic studies. Dec 14, 2017 mosaic down syndrome is a rare, less severe form of down syndrome. Making a karyotype, an online activity from the university of utahs genetic science learning center. This results in a number of characteristic features, such as short. Sep 15, 2010 in all, 80% of antenatal karyotypes are generated by down s syndrome screening programmes dssp.
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