Mutations Causing Conditions which may be Passed On in Families

Mutations refer to changes in the DNA sequence. They can occur spontaneously or due to exposure to certain environmental factors like radiation or specific chemicals.
They can be harmful, neutral, or in some cases, beneficial. Mutations that confer a survival advantage can lead to evolution over generations.
Inherited disorders are caused by mutations in genes. These disorders are passed on from parents to offspring through their gametes (egg and sperm cells).
Examples of inherited disorders include Cystic Fibrosis and Huntingdon’s disease. They are caused by mutations in single genes and are known as single-gene disorders or monogenic disorders.
Cystic Fibrosis is a condition in which thick sticky mucus builds up in the lungs and digestive tract, causing problems with breathing and digestion. It is caused by a mutation in the CFTR gene.
Huntingdon’s disease is a neurological disorder that breaks down nerve cells in the brain over time, leading to cognitive and physical impairment. It’s caused by a mutation in the HTT gene.
These mutations are present in every cell of an individual as they are present in the DNA received from the egg and sperm.
When the mutation occurs in only one copy of the gene, it is known as a dominant mutation. An individual who inherits a dominant mutation will develop the disorder. Huntingdon’s disease is an example of this.
In some cases, the mutation needs to be present in both copies of the gene to cause the disorder. This is known as a recessive mutation. Cystic Fibrosis is an example of a condition caused by a recessive mutation.
Carriers of recessive mutations do not show symptoms of the disease but can pass the mutation onto their offspring.
Genetic testing can be used to identify carriers of these mutations or to diagnose individuals with these disorders. It involves the analysis of DNA to look for specific mutations.
Genetic counselling can provide information and support to people who have, or may be at risk of, genetic disorders. It can help individuals understand their risk and make informed decisions.
Inheritance patterns can be predicted using genetic diagrams (e.g. Punnett squares) or family trees.
Although not all genetic disorders can be treated, the symptoms can often be managed. For some diseases, gene therapy may offer a potential treatment in the future.