06 Genetic Screening and Genetic Counselling

2,154 views

Published on

Published in: Education
0 Comments
4 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
2,154
On SlideShare
0
From Embeds
0
Number of Embeds
1,207
Actions
Shares
0
Downloads
41
Comments
0
Likes
4
Embeds 0
No embeds

No notes for slide

06 Genetic Screening and Genetic Counselling

  1. 1. Genetic screening and genetic counselling ALBIO9700/2006JK
  2. 2. • Genetic screening : the testing of samples of DNA from a group of people to identify the presence or absence of particular alleles and thus the risk of having or passing on particular genetic conditions – Carrier screening • All the individuals in a family may be screened if one family member develops a particular condition that may be genetic • Potential parents may be screened where there is the possibility that one or both of them might carry a recessive allele for some particular condition (cystic fibrosis) ALBIO9700/2006JK
  3. 3. – Prenatal screening – determine the genetic makeup of unborn child • Chromosomal abnormalities, Downs syndrome (especially if mother is over 34), trisomy 13 and trisomy 18 • Single gene disorders, haemophilia, sickle cell anaemia and cystic fibrosis • Neural tube defects, spina bifida and anencephaly • Prenatal screening includes: – Chorionic villus sampling – where the early placental tissue is sampled (at 10-12 weeks of pregnancy) – Amniocentesis – where fetal cells in amniotic fluid are sampled (13-18 weeks) – Intra-uterine blood test – where fetal blood is sampled (16-18 weeks)– Newborn screening – newborn babies screened for phenylketonuria (PKU) by a simple blood test enables the affected individual to be put onto a protective diet ALBIO9700/2006JK
  4. 4. • Genetic counselling : involves an explanation of the results of genetic screening and the implications in terms of probabilities, dangers, diagnosis and treatment – For the individual – to explain the possible future consequences in terms of health of the individual and whether this is likely to have repercussions on their education and employment and even prospects of obtaining insurance – For the couples who want to have children – to explain what the probabilities are of any children inheriting the defective allele and the chances of any child actually having the disease (depending on allele being dominant, recessive or sex-linked) ALBIO9700/2006JK
  5. 5. • Ethical considerations : – Who decides who should be screened or tested? – Which specific disorders should be screened? – Who should be providing the screening? – Should we screen or test for disorders for which there is no known treatment or cure? – What psychological impact might the results have on the individuals involved? – Should the results be confidential? – If not, who should be able to have access to the information? – Should the results be made available to potential employers, insurers etc.? ALBIO9700/2006JK
  6. 6. • Ethical considerations : – Who decides who should be screened or tested? – Which specific disorders should be screened? – Who should be providing the screening? – Should we screen or test for disorders for which there is no known treatment or cure? – What psychological impact might the results have on the individuals involved? – Should the results be confidential? – If not, who should be able to have access to the information? – Should the results be made available to potential employers, insurers etc.? ALBIO9700/2006JK

×