Genetics

Question 1

define precision medicine

Answer 1

form of testing to identify a subgroup of patients that will respond to treatment

Question 2

what is the most common genodermatoses?

Answer 2

tuberous sclerosis

Question 3

presentation of tuberous sclerosis

Answer 3

infantile seizures
ash-leaf macule/shagreen patches
periungual fibromas
facial angiofibroma
cortical tubers (seizures)
enamel pitting

Question 4

genetic inheritance of tuberous sclerosis

Answer 4

AD in TSC1 and 2 genes in chromosomes 9 and 16 which code for tuberin and hamartin (inactivation of tumour suppressors)

Question 5

does tuberous sclerosis show genetic heterogeneity?

Answer 5

yes

Question 6

define genetic heterogeneity?

Answer 6

mutations in different genes can lead to the same phenotype

Question 7

describe variable penetrance

Answer 7

some people do not show features of disease, whereas disease expression causes different people to be affected differently

Question 8

define epidermolysis bullosa

Answer 8

group of genetic fragility conditions with more than 10 genes involved.
can be dominant, recessive, new mutations or acquired

Question 9

three main types of epidermolysis bullosa

Answer 9

simplex
junctional
dystrophic

Question 10

presentation of neurofibromatosis 1

Answer 10

cafe au lait macules (also type 2)
neurofibromas
plexiform neuroma (diffuse)
axillary or inguinal freckling
optic glioma
Lisch nodules
distinct bony lesions

Question 11

genetics of neurofibromatosis 1

Answer 11

activation fo GDP-Ras pathway

Question 12

define haploinsufficiency

Answer 12

only one copy of gene is working so half functioning protein made

Question 13

define dominant negative

Answer 13

expression of abnormal protein interferes with normal protein

Question 14

define gain of function

Answer 14

mutant protein gains new function, affecting cell processes

Question 15

define complete loss of protein

Answer 15

AR- 2 faulty copies of gene produces no protein