Mendelian Inheritance

Question 1

what do disease-associated mutations alter

Answer 1

protein function

Question 2

breifly describe sickle cell disorders (SCD)

wtf is this bro?

Answer 2

• abnormal HB gene
• sickling:
  Pain
  Cold, dehydration, infections, jeaundice, stroke, leg ulcers, eyes, kidneys
• african, mediterranean, middle-east, indian
• anaesthetic issues

Question 3

male

pedigree chart

Answer 3

square

Question 4

female

pedigree chart

Answer 4

circle

Question 5

if both parents carriers, what proportion of children unaffected with be a non-carrier

Answer 5

1/3 as 2 carrier, 1 non-carrier, and 1 affected

Question 6

visual representation of carrier/non-carrier parents

sheet

Answer 6

see sheet

Question 7

what 2 ways can disease-associated mutations which alter protein function be expressed (in terms of phenotype)

weird one ik

Answer 7

as carriers or affected

Question 8

heterozygote advantage

Answer 8

The case in which the heterozygous genotype has a higher relative fitness than either the homozygous dominant or homozygous recessive genotype

Question 9

breifly describe cystic fibrosis

Answer 9

• single gene alteration
• More than 3000 diff mutations
• 1/25 carrier but 1/2500 affected

Question 10

chance someone in population is carrier of cystic fibrosis

Answer 10

1/25

Question 11

if we assume 1/25 population are carriers, explain some chances of family being affected/carriers etc.

cystic fibrosis

Answer 11

• parents of affected male are both obligate carriers
• chance of mother’s sister being carrier = 0.5
• chance of her daughter being a carrier = 0.25
• Chance daughter’s partner is carrier = 1/25
• chance daughter and partner both carriers = 0.25 x 1/25
• chance baby of daughter affevted = 0.25 x 1/25 x0.25

Question 12

achondroplasia

Answer 12

genetic condition affecting a protein in the body called the fibroblast growth factor receptor. In achondroplasia, this protein begins to function abnormally, slowing down the growth of bone in the cartilage of the growth plate

Question 13

what can dominant inheritence disease-associated mutations do to protein function

Answer 13

alter it: non-functional or missing proteint or protein that has gain of function

Question 14

autosomal dominant

Answer 14

pattern of inheritance - one copy of a mutated (changed) gene from one parent can cause the genetic condition. A child who has a parent with the mutated gene has a 50% chance of inheriting that mutated gene

Question 15

common characteristics of autosomal dominant inheritance

Answer 15

• each child has 50% chance of inheriting mutation
• no “skipped” generations
• equally transmitted by men and women
• male to male transmission

Question 16

huntington’s disease - dominant/recessive? effect/type of disease

Answer 16

Autosomal dominant and neuro-degenerative disease

Question 17

duchenne muscular dystrophy

Answer 17

genetic disorder characterized by progressive muscle degeneration and weakness due to the alterations of a protein called dystrophin that helps keep muscle cells intact - X-linked, thus typically affects boys

Question 18

X-linked (sex-linked) inheritance

Answer 18

• only males affected clasically
• can skip generations
• unaffected women and affected men can transmit condition
• no male to male transmission

Question 19

what can multiple genes in the same molecular pathway cause

Answer 19

the same mendelian disease
* long QT, ARVC and cardiomyopathy
* many genes
* each has strong effect
* mode of inheritance can differ:

Autosomal dominant
autosomal recessive
XL variants in > 1 gene

no idea wft this is, just copied from PP

Question 20

pedigree chart

Answer 20

squares and boxes - watch videos on how to calc genetic risk from pedigree structure