Genetics in Medicine

Question 1

define human genetics?

Answer 1

the science of heredity and variation in humans and mechanisms of inheritance and genetic variation. Medical genetics is a subset of this that is important in medicine and medical research e.g. things of clinical importance

Question 2

define molecular genetics?

Answer 2

the study of structure and function of individual genes including DNA

Question 3

what happens when a gene does not perform its normal function correctly?

Answer 3

genetic disorder

Question 4

what can cause inherited disorders?

Answer 4

single gene, imprinted, mitochondrial or chromosomal

Question 5

what do genetic biomarkers show?

Answer 5

susceptibility to a certain disease

Question 6

define pharmacogenetics?

Answer 6

who will respond, in what way, and why including their genes?

Question 7

where can be drug treatments be targetted?

Answer 7

genetic faults which can be germline (Factor IX) or somatic (Imatinib)

Question 8

what are the clinical genetics spectrums?

Answer 8

child - a lot of childhood disease is genetically determined
adult - often more complex
pregnancy - time limited

Question 9

what does a family tree and clinical examination detect?

Answer 9

the pattern of inheritance, and the defining phenotype, and directs testing

Question 10

what are the subsets of diagnostic tests?

Answer 10

non-genetic such as radiology or biochemistry, or genetic such as DNA and chromosomes

Question 11

what is carrier testing used for?

Answer 11

autosomal and X-linked recessive

Question 12

what test is done for inborn errors of metabolism?

Answer 12

enzyme assay - blood test

Question 13

what test is done for thalaessemia?

Answer 13

haematological blood test

Question 14

what test is done for achondroplasia?

Answer 14

skeletal dysplasia Xray

Question 15

what DNA is tested in prenatal testing and why?

Answer 15

test the foetal DNA to prevent genetic disease

Question 16

what is screening?

Answer 16

where a large number of people are tested to see if carrier and given the advice so they do not pass it on

Question 17

what are some advantages of testing?

Answer 17

early diagnosis and interventions, and reproductive choices

Question 18

what are some disadvantages of testing?

Answer 18

there may not be treatment, anxiety,

Question 19

what proportion of children is hospital does rare disease account for?

Answer 19

1/4 to 1/3

Question 20

what does KCNJ10 do?

Answer 20

it changes the ion currents in the brain and leads to epilepsy

Question 21

what happens if there is a mutation in renal salt balance gene such as a mineralocorticoid receptor gene?

Answer 21

rare syndrome of blood pressure

Question 22

what does epilepsy result from?

Answer 22

mutation in ion channels

Question 23

what happens if the TNF alpha receptor gene is mutated?

Answer 23

autoimmune disorders

Question 24

how does microcephaly arise?

Answer 24

mutation in the ASPM gene

Question 25

which cells respond to blood glucose level?

Answer 25

beta cells

Question 26

what enzyme converts glucose to glucose-6-phosphate generating ATP?

Answer 26

glucokinase

Question 27

how is insulin released?

Answer 27

glucose-6-phosphate is an inhibitor of potassium channel, beta cells depolarised, calcium leaves and rise leads to degranulation of insulin to be released

Question 28

what is MODY?

Answer 28

maturity onset diabetes of the young - mutation in glucokinase

Question 29

what is neonatal diabetes caused by?

Answer 29

mutation in the potassium ion channel

Question 30

where do sulfonylureas target?

Answer 30

potassium channel to treat NN diabetes

Question 31

what is chronic myelogenous leukaemia?

Answer 31

it is when a hybrid gene is produced from translocation - abnormal tyrosine kinase - drug target this (chromosome 9 and 22 = Philadelphia chromosome)