Presentation on theme: "Genetic Screening and Counseling. Introduction When you are pregnant, you go through n umber of prenatal tests such as blood test, urine tests, monthly."— Presentation transcript:
Introduction When you are pregnant, you go through n umber of prenatal tests such as blood test, urine tests, monthly medical exams, diet q uestionnaires, and family history tracking. Each of these tests helps to assess the he alth of your baby and to predict any potenti al health risks.
Genetic testing is also one of the tests you migh t choose to have. It identifies the likelihood of h aving certain genetic diseases or disorders to th e children. Some of the genetic disorders are: Down syndrome Sickle cell disease Tay-Sachs disease If your history suggests that genetic testing would be helpful, you may be better to take genetic counseling.
What Is Genetic Counseling? Genetic tests use a variety of laboratory tec hniques in order to determine if a person h as a genetic condition or disease or is likel y to get the disease. Genetic tests are done by analyzing small s amples of blood or body tissues to determi ne if you, your partner, and the baby carry genes for certain inherited disorders.
For example: one of the medical procedur e of genetic testing called a buccal smear uses a small brush or cotton swab to colle ct a sample of cells from the inside surface of the cheek. Then, the sample is sent to a laboratory where technicians look for speci fic changes in chromosomes, DNA, or prot eins. The results are then reported to the g enetic counselor.
Genes: They are composed of DNA which ar e the simplest building blocks of heredity. Th ey are gathered in a person’s chromosomes and form unique “blueprint” for every physica l and biological characteristic of the person
Humans have 46 chromosomes which are arranged in pairs in every living cell. When the egg and sperm join, half of each chrom osomal pair is inherited from each parent. This new combination chromosomes then copies itself again and again during fetal g rowth and development, passing identical genetic information to produce each new c ell in the growing fetus
Human chromosomes carry from 25,000 t o 35,000 genes. However, an error of just one gene (and sometimes, even the error of a single piece of DNA) can cause a seri ous medical condition
Why would you take genetic counseling? To find possible genetic diseases of unborn babies To find out if the parents carry a gene for a disease that might pass on to the baby To screen embryos for disease To test for genetic diseases in adults before they cause any symptoms To conform a diagnosis in a person who has disease symptoms
Positive Results This means that you have the mutation yo u’ve been tested for. It means that you are more likely to get a particular disease than other people, but not necessarily.
Negative results This means that you don’t have the particu lar mutation. This means that the disease doesn’t run in your family. However, it doe sn’t mean that you won’t get the disease. It only means that you are less likely to get t he disease that others.
Types of Genetic Testing Carrier Identification: Genetic tests used by couples whose families have a history of genet ic disorders but whose considering having chil dren. Used to determin e cystic fibrosis, Tay-S achs disease, and sickl e-cell trait.
Prenatal Diagnosis genetic testing of a fe tus. Occurs when there is a risk of bearing a child with genes associated with mental r etardation or physical deterioration. One of the most common genetic disease screen ed by prenatal diagnosis is Down Syndrom e.
Newborn Screening frequently done as a preventative health measure. This test has 52 states in which diseases such as Phen ylketonuria and congenital hypothyroidism can be tested.
Late-onset Disorders Test for adult disea ses cush as cancer and heart disease. Th ese diseases have both genetic and enviro nmental causes. Genetic tests indicate a p redisposition for the diseases.
Identification of genetic info rmation of a specific individu al has received a great deal of press coverage lastly. Pro files (DNA fingerprints) that a re complied from DNA testin g identify unique characterist ics of an individual. This info rmation is now used in legal cases such as criminal inves tigations. It also can be used in major accidents, disasters or wars to determine who ha ve died.
Issues in Genetic Testing Privacy – rights of individuals to maintain priv acy. However, if an infant is found to be a carr ier or likely to develop or be affected by a gen etic disease, these findings might affect the fu ture employability or insurability of the infant. Informed consent - obtaining of permission t o do genetic testing. One must have knowled ge of the risks, benefits, effectiveness, and alt ernatives to testing in order to understand the implications of genetic testing.
Confidentiality - acknowledgment that ge netic information is sensitive and access s hould be limited to those authorized to rec eive it. Future access to a person's genetic information also should be limited.
For further information.. “What is Genetic Testing?” http://www.lbl.gov/Education/ ELSI/Frames/genetic-testing-f.html “Genetic testing” http://www.answers.com/topic/genetic- counseling?cat=health “Genetic counseling” http://www.kidshealth.org/parent/pregnancy_newborn/me dical_problems/genetic_counseling.html “Genetic Testing” http://www.nlm.nih.gov/medlineplus/genetictesting.html# cat1