Interactive Resources for Schools
This topic takes on average 55 minutes to read.
There are a number of interactive features in this resource:
Biology
PSHE / Citizenship studies
Biology
PSHE / Citizenship studies
Science (applied)
Chemistry
Biology
Biology
Human biology
Biology
PSHE / Citizenship studies
Science (applied)
There are a number of genetic diseases which we now know are caused by a defect at a single gene locus. These diseases include haemophiliahaemophilia
An X chromosome-linked recessive genetic disorder which affects the clotting mechanisms of the blood. It mainly affects boys.
A, cystic fibrosiscystic fibrosis
A genetic disease caused by a defective, recessive allele. It is characterised by the production of thick, sticky mucous in the lungs and pancreas which cause respiratory and digestive problems.
, Duchenne muscular dystrophymuscular dystrophy
Inherited condition which leads to the progressive weakening and breakdown of muscles. This in turn leads to increasing levels of disability. In its most severe forms it can be fatal.
, sickle cell disease, Huntington’s disease and SCID (severe combined immunodeficiencysevere combined immunodeficiency
A very rare genetic disorder causing children to be born without an effective immune system, so they are extremely vulnerable to any form of infection.
). Gene therapygene therapy
A new, experimental method of fighting disease by replacing a defective gene with a healthy gene.
offers the hope of introducing healthy genes into the cells of people affected by the diseases, enabling them to function normally and restoring the patient to health. New technologies such as CRISPR-Cas9CRISPR-Cas9
A genome editing tool, based on a bacterial system, which provides a precise, fast and relatively cheap method for manipulating the genome of an organism.
are making it easier for scientists to manipulate the genome accurately and safely.
One of the first diseases targeted for gene therapy was cystic fibrosis (CF). For a considerable time, success was very limited. However, from 2015, results have been more promising. Researchers are using different approaches to carry the healthy genes into the lung cells of affected patients. Some are using viruses, some are using lipid bubbles. In 2015, one group recorded lung function in a group of patients treated by gene therapy as 3.7% better than the placeboplacebo
A control that is used in drug trials. It looks exactly the same as the medicine under test but it does not contain the active ingredient.
group. This isn’t much, but for patients with CF, every little bit makes a real difference. 2017 sees the start of a new round of human trials using different, and hopefully more effective, vectors to transmit healthy genes into the lungs of CF patients.
There are a number of trials showing real promise in using gene therapygene therapy
A new, experimental method of fighting disease by replacing a defective gene with a healthy gene.
to treat some of the many forms of inherited blindness. Another disease where gene therapy showed great initial promise was in the treatment of severe combined immunodeficiencysevere combined immunodeficiency
A very rare genetic disorder causing children to be born without an effective immune system, so they are extremely vulnerable to any form of infection.
(SCID). Major problems arose, with some patients developing leukaemialeukaemia
The umbrella name given to a number of cancers of the bone marrow and other organs which produce white blood cells.
– but scientists and doctors persisted and now there are continuing clinical trials of versions of gene therapy for SCID which are showing promise in both infants and older children.
In 2017, scientists announced the successful treatment of a teenage boy who was severely affected by the genetic disorder sickle cell disease. Doctors removed some of his bone marrowbone marrow
Found in the centre of bones, it contains adult stem cells which divide and differentiate to produce red and white blood cells.
, added new genes to the cells to code for healthy beta-globin, and then replaced the bone marrow. Fifteen months later the cells are still making healthy haemoglobinhaemoglobin
The protein that carries oxygen within red blood cells.
and the boy is free from symptoms.
For more information, check out the following content in our Genetic engineeringgenetic engineering
Genetic engineering involves changing the DNA of an organism, usually by deleting, inserting or editing a gene to produce desired characteristics.
resource:
There are many ethical questions about using such new and experimental techniques on patients who are already very sick. Here are two pairs of commonly expressed opinions, one in favour of treatments such as gene therapy and one against. Use the resources listed below – and any others you chose to use – to find out more about gene therapy and the progress made so far. Then from each pair of statements chose the one closest to your own viewpoint. Write one or two paragraphs expressing your opinion, putting forward the main arguments for and against the idea and justifying your position.
|
A:
|
|
|
B:
|
|
