Typical Mendelian Inheritance

Question 1

Autosomal dominant inheritance

Answer 1

Male-male transmission
vertical degree pattern
equal disease frequency and severity between males and females

Variable expressivity: People within the same family can be affected differently even with the same mutation

Incomplete penetrance: have the mutation but may not develop the disease

Offsprings of affected individuals uslally have a 50:50 risk

Question 2

Autosomal dominant condition example

Answer 2

breast cancer, adult polycystic kidney disease, huntingtons disease

Question 3

Autosomal recessive

Answer 3

Equal frequency and severity in males and females
horizontal degree pattern
Disease expressed homozygotes
-homozygous - 2 mut alleles
-compound heterozygotes - 2 different mut on same gene

Importance of consaguinity
expressivity more contant within family

Question 4

Auosomal recessive disease examples

Answer 4

CF 
PKU 
Congeintal adrenal hyperplasia 
Spinal muscular atrophy (SMA) 
haemochromatosis

Question 5

X-linked recessive features

Answer 5

Male > female 
No male-male transmission 
Pedigree pattern = knights move 
Male -female transmission 
-all daughters are carriers 
Female- female 
-50% daughters carriers

Question 6

X-linked recessive examples

Answer 6

Duchenne muscular dystrophy

Becker muscular dystrophy

Question 7

Skewed X inactivation

Answer 7

x-inactivating process not being completed

Question 8

X-linked dominant

Answer 8

never male-male transmission
vertical pedigree pattern
all daughter affected - male-female
50% daughters affected - female-female

Question 9

X-linked dominant genetic conditions

Answer 9

Vitamin D resistant rickets - (PHEX) gene 
Rett syndrome (MECP2) 
Incongenti pigmenti (NEMO)

Question 10

mendelian

Answer 10

Single gene disorder

Question 11

Obligate carrier

Answer 11

must be carrier from family tree, show no disease symptoms