Secondary Science
Key Stage 4
Genetics and Medicine - Genes and Disease
Supporting information for teachers
PROGRAMME SYNOPSIS
Genes and Disease shows how modern genetic research is helping us to understand a rare life-threatening heart condition, and the more common skin condition, eczema.
Susie Murray has a rare inherited heart condition called long QT, which, if left untreated, can lead to rapid heart beats, blackouts and even sudden death. Long QT is described as ‘a single gene condition’ but clinical geneticist, Dr Bill Newman, explains that there are at least eight genes that can be involved.
Eczema is an example of a common and complex condition. One in five children in the UK develops eczema, which is caused by both genetic and environmental factors. Professor Irwin McLean tells us that it is only since the arrival of large-scale genomic tests that scientists have been able to investigate all the factors involved and identify new genes contributing to eczema.
The latest genetic research provides powerful tools to understand the causes of different illnesses. It is hoped that by identifying the genetic factors involved, it will be possible to develop better treatments for conditions, such as long QT and eczema.
KEY MESSAGES
Single-gene genetic conditions
Conditions that run in the family, like Long QT Syndrome, usually show that the disease is inherited – meaning that genes are involved in causing the disease.
Differences to a single gene can result in proteins that don’t function correctly, causing disease.
Scientists cannot yet diagnose all single-gene conditions, but technological advance will enable more diagnosis of these rare diseases.
Common and Complex Disease
Common and complex diseases are caused by several genetic differences and lifestyle factors.
Scientists use Genome-Wide Association Studies to investigate the entire human genome. They find differences in genes which correlate with common diseases.
Scientists work with thousands of DNA samples to ensure that the differences they find are not due to chance alone.
Genetic differences cannot be said to ‘cause’ the disease; the results provide a probability that an individual will develop the disease.
Some rare diseases are caused by changes in a single gene. Most common diseases are brought about by the action of several genes, and by the interaction between genes and environment.
The pace of genetics research is increasing rapidly. New technologies will impact on diagnosis, prevention and potentially treatments for disease.
CURRICULUM LINKS
How Science Works:
1a Understand how scientific data is collected and analysed
1d Understand that there are some questions which science cannot currently answer, and some that science cannot currently address.
4a The use of contemporary scientific and technological developments and their benefits, drawbacks and risks.
OCR 21st Century Science
Module B1.2
3 Recall that chromosomes carry in a pair carry the same genes in the same place, but that there are different versions of genes called alleles.
4. Understand that a person may have two alleles the same or two different alleles for any gene
Module B1.3
2. Understand that most characteristics are also affected by environmental factors, for example, lifestyle factors contributing to disease.
AQA – Science A
Module 11.6
Different genes control the development of different characteristics
Edexcel
Topic 2 – relating to:
2.10 Explore the phenomenon that organisms have a size range for that particular
species: height in humans is a continuous variable, influenced by a number of
genes, hormones and nutrition.
USEFUL WEBSITES
Nowgen
Genome British Columbia
National Human Genome Research Institute (USA)
SADS UK (Sudden Arrhythmic Death Syndrome Support Group)
British Skin Foundation
Nowgen is a leading centre for genetics in healthcare and sets out to inform and improve the practice of genetic medicine. Through the Nowgen Schools Genomics Programme we aim to narrow the gap between genomics research and classroom genetics.