Keeping People Healthy: Week Two Flashcards
What are the three main types of single gene mutations?
- Autosomal dominant
- Autosomal recessive
- X-linked recessive
There is a vertical pattern with many generation affected. Is the condition dominant or recessive?
Dominant
There is a horizontal pattern. Is the condition dominant or recessive?
Recessive
When there are both females and males affected, is this autosomal or x-linked?
Autosomal
When there is male to male transmission, s this autosomal or x-linked?
Autosomal
What is the knights-move inheritance?
This is when two males are affected through an uninfected female. There are only males affected and this is X-linked recessive.
What are some symptoms of Down Syndrome?
- upward slanting of eyes
- small nose
- low set ears
- learning difficulties
- higher incidence of conditions like heart problems
What is triploidly?
Three sets of chromosomes
What is XXY?
Klinefelter syndrome
What is the chromosome arrangement in Klinefelter syndrome?
XXY
What is triple X syndrome?
XXX
What is the definition of malformation?
This is a structural abnormality causes by an abnormal process that is intrinsic to development.
Give an example of a malformation
Spina Bifia
What is the definition of Disruption?
This is a defect in the body causes by a process that interferes with the normal development.
Give an example of a disruptive disease
Thalidomide induced
What is the definition of Deformation?
This is a structural deformity caused by mechanical forces
What is an example of deformation?
Amniotic band constriction
What does thalidomide affect during pregnancy?
Limb development
What does tetracycline affect during pregnancy?
Tooth enamel
What does streptomycin affect during pregnancy?
Inner ears
What does methotrexate affect during pregnancy?
Craniofacial development
What kind of drug is methotrexate?
DMARD
What condition is caused when a pregnant women is dependent on alcohol?
Fetal alcohol syndrome
Why is screening done?
This is done to identify individuals who are more likely to be helped rather then a harmed by further tests or treatment. Screening uses a defined population.
What group of people get AAA screening?
Men aged 65
What group of people get diabetic retinopathy screening?
Diabetics over 12
What is the best method for monitoring the effectiveness of a screening programme?
Randomised controlled trials
What are some pitfalls in studying screening effects?
- healthy volunteer bias
- Lead time bias
- Length time bias
What is Lead time bias?
Survival period is perceived to be a lot longer
What is length time bias?
The tests are more likely to diagnose slow-growing tumours and these have a longer survival rate
What is sensitivity?
The test identifying people with the condition
What is specificity?
The test identifying people without the condition
What is positive predicted result?
How likely the positive result is true
What is negative predicted result?
How likely the negative result is true
What are some potential harms of screening programmes?
- false positive and false negatives
- over diagnosis and treatment
- resource allocation and opportunity costs
- exacerbating inequalities
What is the meaning of malnutrition?
This is a condition that results from eating a diet in which nutrients are either too much or not enough
What is food insecurity?
A state of being without reliable access to a sufficient quality of nutritious food
What are some factors contributing to under-nutrition in the elderly?
Physiological: illness
Social: difficulties accessing foods, affording foods, inability to prepare food, social isolation
What is the definition of severe acute malnutrition?
Below 3 stranded deviation of median weight for height, visible severe wasting or nutritional oedema
What is the definition of moderate malnutrition?
Weight loss and 2-3 standard deviations for median weight of height
What is the definition of mild malnutrition?
Weight loss and 1-2 standard deviations below median weight for height
Name the determinants of heath and well-being
- people
- lifestyle
- community
- local economy
- activities
- built environment
- natural environment
- global ecosystem
What factor is vWF bound to and what is the function of this?
vWF is bound to factor 8 and this allows factor VIII to be inactive. Factor VIII released by thrombin action.
Are mutations in the germ line inherited or non-inherited?
Inherited
Are mutations in the somatic cells inherited or non-inherited?
Non-inherited
What is the disposable soma aging theory?
DNA repair activity is much higher in the germ line and higher in terms of energy. Soma is less important and mutations rates are higher, therefore, cells will accumulate DNA damage and die.
What are two consequences of DNA damage?
Cancer and Aging.
What carries out DNA unwinding during replication?
DNA helicase
What enzyme mediates DNA replication and what ends does it travel from?
DNA polymerase mediates DNA replication and goes from the 3’ - 5’ end.
What enzyme follows DNA polymerase and functions to detect any DNA damage?
DNA mismatch repair complex.
What happens with DNA mismatch repair complex detects DNA damage?
The DNA mismatch repair complex will send signals to DNA polymerase to stop activity. DNA exonuclease will be recruited and this cuts the new daughter strand until the damage has been removed.
What cancer is common from a mutation in the DNA mismatch repair complex?
Non-polyposis colon cancer
Give four examples of DNA damage
- base modification
- base loss
- single stranded break
- double stranded break
Give an example of endogenous mutagens
Hydrogen peroxide
What mutations do x-rays cause?
Double-stranded breaks
What mutation does UV radiation cause?
Thymidine dimerization
Explain the function of Nucleotide excision complex
This complex detect DNA damage. This complex is made up of many different subunits and each part is specialised for a certain damage. They will bind to damage and recruit DNA endonuclease.
DNA endonuclease will make a single-stranded cut and remove the DNA damage. DNA polymerase will then be recruited to replace the bases.
Name two conditions where there is defective nucleotide excision repair complex
- xeroderma pigmentosum
- cockayne syndrome
What are some symptoms of xeroderma pigmentosum?
There is a high risk of skin caner. There is accelerated aging and dwarfism.,
What are some symptoms of cockayne syndrome?
There is accelerated aging and dwarfism.
What are the two methods for repairing double-stranded breaks?
- homology dependent
- non-homology end-joining
Explain the method of homology dependent method of repairing double stranded breaks
An endonuclease is recruited and this exposes the DNA damage. The sister chromatid is recruited and replication occurs. This process requires energy but is very reliable as no information is lost. This occurs in germ-line cells.
Explain non-homology end-joining
This occurs more in somatic cells. DNA that is damaged is removed and two ends, where the DNA has been removed, join together. This means that information is lost.
What chromosomes are involved in the Philadelphia chromosome translocation?
9 and 22
What condition does the Philadelphia chromosome translocation cause?
Chronic Myelogenous Leukaemia
What chromosome is ABL located on?
Chromosome 9
What chromosome is BCR on?
Chromosome 22
Explain the pathology of Philadelphia chromosome translocation?
A trigger causes a translocation mutation where ABL, located on chromosome 9, is switched to chromosome 22. This crates the fusion-gene, BCR-ABL. This causes uncontrolled growth of the myeloid cells.
What is Nijmegen breakage syndrome?
This is an autosomal recessive condition where there is defective homologous dependent repair system.
What genes are mutated in inherited breast and ovarian cancer?
BRCA1 and BRCA2 (these are involved in homology dependant repair.
Describe the two pathways that damaged DNA can go through
- Little DNA damage allows repair
- High DNA damage causes apoptosis
What is the difference between vaccine and immunization?
Vaccine: induced immunity through vaccine
Immunization: vaccine induced immunity and antibody transfer
What are some aims of immunization?
- to protect those at risk
- eradicate or contain a disease
What is the definition of eradication?
Disease and causative agent removed worldwide