causes of disease overview

Question 1

what is a condition with no known cause known as

Answer 1

idiopathic

Question 2

what can diseases be classified as

Answer 2

intrinsic

extrinsic

Question 3

describe the intrinsic causes

Answer 3

• change in an individuals genome
  (nuclear or mitochondrial, inherited mutations and other genetic variations, de novo mutations, epigenetic modifications)
• typically alter function of a gene
• effects of genetic variation can manifest at variety of levels. (cell autonomously and cell non-autonomously)

autonomously = cell x no longer expresses structural protein Y, so cell X is wrong shape

Question 4

describe extrinsic causes

Answer 4

injury 
infection 
nutrition and diet 
lifestyle 
chemical poisoning 
exposure to radiation

Question 5

is age a cause

Answer 5

age just means time in context of causes that accumulate

• can be an intrinsic cause when it describes biological process of ageing
• many diseases associated with chronic inflammation also have biological ageing as a cause

Question 6

alternative descriptions

Answer 6

for most diseases causes grouped as genetic and environmental

terms are versions of intrinsic and extrinsic the are more reflective of that disease.

Question 7

examples of intrinsic disease

Answer 7

cancer (leukaemia, lymphoma, myeloma, breast and prostate)

developmental diseases (neural tube defects)

inherited anaemia (sickle cell disease, b-thalassaemia)

inherited metabolic diseases (phenylketonuria)

Question 8

is Down syndrome intrinsic

Answer 8

yes

• trisomy of chromosome 21, inherited at conception.

Question 9

is COVID 19 extrinsic

Answer 9

yes

• infection with SARs-CoV-2

Question 10

causes of lung cancer

Answer 10

smoking tobacco, chemicals and workplace risks, air pollution, exposure to radon gas = extrinsic

previous lung disease and family history = intrinsic