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Human genetic diseases caused by gene mutations

Source: University of Michigan School for Environment and Sustainability, licencja: CC BY 2.0, [online], dostępny w internecie: www.flickr.com.

Link to the lesson

Before you start you should know
  • that sexual reproduction results in genetic variation;

  • that some diseases are the result of errors that arise in the DNA.

You will learn
  • 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.

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Nagranie dźwiękowe abstraktu
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Inheritance of cystic fibrosis
Source: Dariusz Adryan, licencja: CC BY 3.0.

Most genetic diseases are caused by mutationsmutationmutations 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 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.

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Ilustracja przedstawia schemat na którym są podpisy: MUTATIONS- na lewo- in the germ cells- od tego członu na lewo: gene; na prawo: chromosome; następnie na prawo in somatic cells. Dodano opisy: 1. They are inherited, 2. They can be inherited if the progeny is fertile, 3. They are not inherited
Mutation inheritance
Source: GroMar Sp. z o.o., licencja: CC BY-SA 3.0.
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Phenyloketynuria test is performed on all newborns three days after birth
Source: Jared Tarbell, Tomorrow Sp. z o.o., www.flickr.com, licencja: CC BY 3.0.
Task 1
Wyjaśnij kluczowe pojęcia związane z tematem abstraktu
Wyjaśnij kluczowe pojęcia związane z tematem abstraktu
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Selected hereditary diseases caused by gene mutations
Source: GroMar Sp. z o.o., licencja: CC BY-SA 3.0.
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Exercise 1
Select all types of mutations that can be passed on to the offspring. Możliwe odpowiedzi: 1. gene mutation in a somatic cell, 2. gene mutation in a reproductive cell, 3. chromosomal mutation in a somatic cell, 4. chromosomal mutation in a reproductive cell
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Exercise 2
Combine the name of the disease with the way it is inherited haemophilia Możliwe odpowiedzi: 1. autosomal dominant, 2. autosomal recessive, 3. conjunction with the X chromosome. Huntington's chorea Możliwe odpowiedzi: 1. autosomal dominant, 2. autosomal recessive, 3. conjunction with the X chromosome. phenylketonuria Możliwe odpowiedzi: 1. autosomal dominant, 2. autosomal recessive, 3. conjunction with the X chromosome
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Exercise 3
Complete the gaps in the text using appropriate words. In most cases, (uzupełnij) mutations are responsible for genetic diseases. Diseases caused by (uzupełnij) mutations are much rarer. Gene mutations can be inherited in a recessive or (uzupełnij) way, or as (uzupełnij) diseases. Some of the diseases caused by gene mutations, if properly (uzupełnij), do not pose a threat to the patient's life, so they can pass the genes to their offspring. Thanks to this, the (uzupełnij) gene can be passed on to subsequent generations. Możliwe odpowiedzi: 1. treated, 2. dominant, 3. defective, 4. sexually linked, 5. gene, 6. chromosome 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

mutation
mutation
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Nagranie dźwiękowe słówka

mutacja – nagła, trwała zmiana w informacji genetycznej organizmu, polegająca na zmianie struktury lub ilości materiału genetycznego

gene mutation
gene mutation
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Nagranie dźwiękowe słówka

mutacja genowa – jeden z typów mutacji; polega na zmianie sekwencji nukleotydów w DNA, co może powodować powstanie nowych alleli genów