Human genetic diseases caused by gene mutations
that sexual reproduction results in genetic variation;
that some diseases are the result of errors that arise in the DNA.
to distinguish between hereditary and non‑hereditary changes and to give examples of them;
to give examples of human diseases that are caused by mutations.
Most genetic diseases are caused by mutationsmutations in single genes. The mutated allele is usually recessive. If it occurs in the population once per 100 alleles, then the probability of developing a particular disease is 1: 10,000. Genetic diseases are usually very severe and incurable. Medicine can only relieve their symptoms.
One of the more common recessive genetic diseases caused by gene mutationgene mutation is cystic fibrosis. This disease is caused by a mutation in the gene located on chromosome 7. Cystic fibrosis is the production of thick mucus by the glands lining the airways and the digestive system. Huge amounts of sticky mucus impede breathing and digestion and facilitate the development of pathogenic bacteria. Over 1,600 different mutations of this gene are known to cause this disease.
Another common genetic disorder caused by recessive mutation is phenylketonuria. People with this disease do not have the enzyme that breaks down the phenylalanine amino acid, which, when its level is too high, can damage the nervous system. Early detection of the disease allows to start a diet low in phenylalanine, which limits the effects of the disease.
Mark all types of mutations that can be passed on to the offspring.
- gene mutation in a somatic cell
- gene mutation in a reproductive cell
- chromosomal mutation in a somatic cell
- chromosomal mutation in a reproductive cell
Combine the name of the disease with the way it is inherited
autosomal recessive, conjunction with the X chromosome, autosomal dominant
| haemophilia | |
| Huntington's chorea | |
| phenylketonuria |
Complete the gaps in the text using appropriate words.
sexually linked, chromosome, dominant, treated, gene, defective
In most cases, .............................. mutations are responsible for genetic diseases. Diseases caused by .............................. mutations are much rarer. Gene mutations can be inherited in a recessive or .............................. way, or as .............................. diseases. Some of the diseases caused by gene mutations, if properly .............................., do not pose a threat to the patient's life, so they can pass the genes to their offspring. Thanks to this, the .............................. gene can be passed on to subsequent generations.
Summary
The diseases caused by gene mutations include: cystic fibrosis and phenylketonuria, conditioned by recessive alleles, and Huntington's chorea, conditioned by the dominant allele.
Keywords
phenylketonuria, genetic diseases, allele
Glossary
mutacja – nagła, trwała zmiana w informacji genetycznej organizmu, polegająca na zmianie struktury lub ilości materiału genetycznego
mutacja genowa – jeden z typów mutacji; polega na zmianie sekwencji nukleotydów w DNA, co może powodować powstanie nowych alleli genów