Genetic Conditions – GCSE Biology (Combined) CCEA Revision

Genetic conditions are diseases or disorders caused by abnormalities in a person’s genome.
These can be due to changes in a single gene, several genes, or due to changes in the overall structure or number of chromosomes.
Genetic conditions can be either inherited from parents or be the result of mutations in an individual’s genome.

Gene mutations can lead to the production of proteins that do not function properly or are not produced at all, resulting in a genetic condition.
Chromosomal disorders, where there are missing or extra chromosomes or pieces of chromosomes, can also result in genetic conditions.
Changes to genes or chromosomes can occur naturally during the formation of egg or sperm cells, and be passed to the offspring.

Cystic Fibrosis: A condition caused by a mutation in the CFTR gene, which leads to a build-up of thick, sticky mucus in the lungs and digestive system.
Down’s Syndrome: A chromosomal disorder resulting from an additional chromosome 21, leading to learning disabilities and certain physical features.
Huntington’s disease: An inherited condition caused by a mutation on the HTT gene, affecting the brain and nervous system.

Some genetic conditions like cystic fibrosis and sickle cell anaemia are recessive, meaning an individual must inherit two copies of the mutated gene to be affected.
Some conditions like Huntington’s disease are dominant, and an individual needs only one copy of the mutated gene to have the condition.
The chance of inheriting a genetic condition is not influenced by the gender of the parent, unless it is a sex-linked condition, these are disorders associated with genes located on the sex chromosomes.

With the advent of genetic technologies, many genetic conditions can now be diagnosed before birth, or even before implantation in the case of IVF screening.
Some genetic conditions can be managed with treatments that improve the symptoms, but most cannot be cured.
Genetic conditions can have a major impact on life expectancy and quality of life, and many people affected by genetic conditions require long-term care.
In some cases, knowledge of a serious genetic condition can lead to ethical considerations around reproductive choices, such as whether to have children who might inherit the condition.

Scientific research is crucial in understanding the causes of genetic conditions, how they affect the body, and for developing new treatments.
The use of genetic technologies in the diagnosis and potential treatment of genetic conditions is a rapidly expanding field.
Part of this field includes gene therapy, which tries to change the genes directly, or genetic engineering, which involves adding, removing, modifying, or manipulating the genes in a living organism.