S15) Epigenetics Flashcards Preview

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Flashcards in S15) Epigenetics Deck (18)
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1
Q

Identify the symptoms of Sickle Cell Anaemia

A
  • Anaemia
  • Fever
  • Severe pain
  • Sudden death
2
Q

Describe the treatment for Sickle Cell Anaemia

A

Treatment usually aimed to limit symptoms and complications

3
Q

Describe the molecular basis for Sickle Cell Anaemia

A
  • SCA is caused by a single DNA mutation, an A to a T in the beta-globin gene
  • Glutamate changes to valine in the amino acid chain
4
Q

Both beta globin proteins need to be mutated to cause Sickle cell anaemia.

What does this tell us about the disease?

A

Autosomal recessive inheritance

5
Q

What is sickle cell trait?

A
  • Sickle cell trait is a milder form of sickle cell anaemia wherein individuals are heterozygous for the mutation
  • Increases resistance to malaria
6
Q

Discuss the geographical variation with sickle cell anaemia

A
  • SCA is very rare in non-African populations and common in populations with African ancestry
  • Similarity in distribution across populations with malaria endemicity
7
Q

What is epigenetics?

A

Epigenetics is the study of heritable changes in gene expression that does not involve changes to the underlying DNA sequence

8
Q

What is Huntington’s disease?

A

Huntington’s Disease in an inherited neurodegenerative disease, involving the death of brain cells

9
Q

Identify 4 symptoms of Huntington’s Disease

A
  • Seizures
  • Abnormal gait
  • Personality change
  • Dementia
10
Q

Describe the molecular basis for Huntington’s disease

A

Mutation is a short tandem repeat (STR)

11
Q

What pattern of inheritance does Huntington’s disease follow?

A

Autosomal dominant inheritance

12
Q

How can Huntington’s Disease be detected?

A

DNA test detection: use a polymerase chain reaction (PCR) to amplify the CAG repeat

13
Q

In terms of Huntington’s disease, what is meant by the term anticipation?

A
  • Age of onset commonly 40-50 (varies)
  • Anticipitation is when the age of onset becomes earlier and symptoms become more severe from generation to generation
14
Q

How can age of onset be determined in Huntington’s disease?

A
  • Age of onset is affected by CAG repeat length
  • However, there is still a lot of variation as the influence of the age of onset is multifactorial
15
Q

Identify two approaches in which Huntington’s Disease can be treated

A

We all have the HTT gene and it is turned on in all cells:

  • Appproach 1: use a suppressor screen – delete every gene in turn and identify genes that, when deleted, prevent HD.
  • Approach 2: chemical inhibition of kynurenine biochemical pathway
16
Q

What are developmental disorders?

A

Developmental disorders are a group of psychiatric conditions originating in childhood that involve serious mental and physical impairment in different areas

17
Q

Provide the clinical basis for developmental disorders

A
  • Individually rare, but collectively common
  • 2-5% of children born with a major congenital malformation or show neurodevelopmental disorder in childhood
18
Q

What causes developmental disorders?

A
  • Environment (infection, maternal alcohol)
  • New mutation in a gene