Molecular basis of human disease Flashcards
Do genetics have a role in all diseases?
Genetics plays a role, to a greater or lesser extent, in all diseases.
What is the nature vs nurture arguement?
What you are depends on your nature (biological or genetic predisposition that impacts ones traits) or nurture (how you were brought up)
What contributes to disease processes?
Variations in our DNA and differences in how that DNA functions (alone or in combinations), alongside the environment contribute to disease processes.
Define nature
“nature” refers to the biological/genetic predispositions that impact one’s human traits — physical, emotional, and intellectual.
Define nurture.
Nurture,” in contrast, describes the influence of learning and other “environmental” factors on these traits. eg: your upbringing.
Define disease.
A disease is a disorder of structure or function in a human, animal, or plant, especially one that produces specific symptoms or that affects a specific location and is not simply a direct result of physical injury
Give some examples of diseases.
- Infectious diseases (common cold)
- Deficiency diseases (scurvy)
- Mendelian hereditary diseases (sickle cell disease)
- Non-Mendelian hereditary diseases (anxiety, depression, Cardiovascular disease risk)
- Physiological diseases – including autoimmune diseases
Define mendelian hereditary disease
Disorders which occur when specific mutations in single genes — called germline mutations — are inherited from either of one’s two parents.
Examples of mendelian hereditary diseases.
cystic fibrosis, sickle cell disease, and Duchenne muscular dystrophy.
Define non-mendelian hereditary diseases.
conditions that are caused by factors other than changes in DNA sequence, such as environmental exposures or errors during embryonic development.
Define Deficiency diseases
diseases caused by a deficiency of nutrients. E.g. vitamin deficiency. E.g. rickets caused by lack for vitamins + lack of sunlight.
Define epigenetics
Epigenetics is the study of how your behaviours and environment can cause changes that affect the way your genes work.
What may happen if parent individuals have a poor diet?
Parent individuals with a nutrient-poor, high-fat, or high-sugar diet may transmit altered
DNA methylation states to offspring that result in metabolic or developmental disorders
What is dna bound to?
DNA is bound to histones, look slike beans on a string.
How are methol groups added to dna?
DNA can be methylated. Methol groups are added to Cs.
What has an effect on the expression of genes?
both epigenetics and dna changes.
Define genetic disorder.
Agenetic disorderis adiseasethat is caused by a change, or mutation, in an individual’s DNA sequence
What are the 3 types of genetic disorder?
- Single-gene disorders
- Chromosomal disorders
- Complex disorders
WHat are single-gene disorders?
Single-gene disorders, where a mutation affects one gene: sickle cell anaemia, cystic fibrosis
What are chromosomal disorders?
Chromosomal disorders, where chromosomes (or parts of chromosomes) are missing/changed/imbalanced - Down syndrome is a chromosomal disorder
What are complex disorders?
Complex disorders, where there are mutations in two or more genes. Often lifestyle and environment play a role. Colon cancer is an example but so are potentially cardiovascular disease, schizophrenia, depression, bipolar disorder
What diseases/disorders are predictable?
- Mendelian (single gene) disorders can be predicted
- In contrast, infectious diseases are less predictable
- Risk of recurrence is also predictable
What diseases can be predicted before symptoms even begin?
Pre-symptomatic testing is possible
- Some inherited illnesses can be predicted before symptoms start – genes present in every cell. e.g. cystic fibrosis
What techniques are used to predict diseases before they begin?
antenatal testing
newborn screening, heel prick blood test (plasma IRT), carrier testing, cheek cells or blood test
