Autosomal Dominant

Question 1

Law of Segregation

Answer 1

each parent passes one randomly selected allele for each trait

Question 2

Law of Independent Assortment

Answer 2

separate genes are passed independently of one another

Question 3

Autosomal Dominant traits are manifested in _______.

Answer 3

homozygotes and heterozygotes

Question 4

Autosomal Dominant traits map to an _______.

Answer 4

autosome

Question 5

Autosomal Dominant traits are manifested in which gender?

Answer 5

both males and females

Question 6

Autosomal Dominant traits can be passed on by which parent?

Answer 6

either one

Question 7

Autosomal Dominant pedigrees have ______ patterns.

Answer 7

vertical

Question 8

It is rare to have a _______ autosomal dominant condition.

Answer 8

homozygous

Question 9

Penetrance

Answer 9

having the genotype and showing the phenotype

Question 10

100% penetrance means?

Answer 10

If you have the genotype, you will always show the phenotype

Question 11

Name a disease with 100% penetrace.

Answer 11

achondroplasia

Question 12

What is the incidence rate of achondroplasia?

Answer 12

1:15,000

Question 13

What is the new mutation rate in achondroplasia?

Answer 13

80%

Question 14

What are the signs and symptoms of achondroplasia?

Answer 14

short stature, Rhizomelic limb shortening, trident hands, frontal bossing, small foramen magnum, genu varum

Question 15

Achondroplasia is caused by a ___ mutation in the _____ gene on chromosome ____.

Answer 15

amino acid substitution of G to A; FGFR3; 4

Question 16

Paternal age effect can be seen in diseases such as _____.

Answer 16

achondroplasia

Question 17

What is the paternal age effect due to?

Answer 17

increased error rates in spermatogenesis in older men

Question 18

pure dominant

Answer 18

homozygotes and heterozygotes are equally affected

Question 19

incompletely dominant

Answer 19

homozygotes are more severely affected

Question 20

Which diseases have reduced penetrance?

Answer 20

retinoblastoma, BRCA, Huntington Disease

Question 21

Achondroplasia is fatal in the ______ form.

Answer 21

homozygous

Question 22

What is the incidence rate for retinoblastoma?

Answer 22

1:15,000 live births

Question 23

Retinoblastoma associated protein regulates _____.

Answer 23

the cell cycle

Question 24

Retinoblastoma is ____ penetrant.

Answer 24

90%

Question 25

Retinoblastoma gene is ____ on chromosome ____.

Answer 25

RB1; 13

Question 26

On a pedigree, you might see incomplete penetrance when _____.

Answer 26

a generation is skipped

Question 27

expressivity

Answer 27

the degree to which the phenotype is expressed given a genotype

Question 28

Name 2 diseases with variable expressivity.

Answer 28

1) neurofibromatosis type 1 | 2) osteogenesis imperfecta type 1

Question 29

Neurofibromatosis type 1 incidence rate? new mutation rate?

Answer 29

1:3000 births; 50%

Question 30

How is neurofibromatosis type 1 clinically diagnosed?

Answer 30

café-au-lait spots, neurofibromas, freckling in axillary or inguinal areas, optic glioma, lisch nodules, osseous lesions, 1st degree relative

Question 31

1st degree relative

Answer 31

share 50% of your genes (parents, siblings, children)

Question 32

What is the mutation in neurofibromatosis type 1? What kind of mutation? What chromosome?

Answer 32

NF1; loss of function; 17

Question 33

What is the incidence rate of osteogenesis imperfect type 1?

Answer 33

1:30,000

Question 34

What are the signs and symptoms of osteogenesis imperfect type 1?

Answer 34

multiple fractures, mild short stature, adult onset hearing loss, blue sclera

Question 35

What is the mutation in osteogenesis imperfect type 1? What does it do? Which chromosome?

Answer 35

COL1A1; reduces collagen production by half; 7

Question 36

What is the incidence rate of Marfan Syndrome? What is the new mutation rate?

Answer 36

1:5000; 50%

Question 37

What is the mutation in Marfan Syndrome? What does it do? Which chromosome?

Answer 37

FBN1; decreases microfibrils and increases flexibility and stretching of tissues; 15

Question 38

locus heterogeneity

Answer 38

a mutation in more than one locus causing the same clinical condition

Question 39

What is an example of a locus heterogeneity disease?

Answer 39

AD polycystic kidney disease

Question 40

What is the incidence rate of AD polycycstic kidney disease? What is the de novo mutation rate?

Answer 40

1:1000; 5%

Question 41

What are the clinical symptoms of AD polycycstic kidney disease?

Answer 41

bilateral renal cycts, cysts elsewhere, vascular abnormalities, renal disease

Question 42

What is the mutation and chromosome in AD polycycstic kidney disease?

Answer 42

1) PKD1 of chromosome 16 (85% of cases) | 2) PKD2 of chromosome 4 (15% of cases)

Question 43

What is the incidence rate of familial hypercholesterolemia? What is the new mutation rate?

Answer 43

1:200-500; very low

Question 44

What are the clinical manifestations in familial hypercholesterolemia?

Answer 44

very high cholesterol and LDL; xanthomas; CAD and death

Question 45

xanthomas

Answer 45

cholesterol deposits under the skin

Question 46

What is the mutation in familial hypercholesterolemia?

Answer 46

mutations of genes: 1) LDLK 2) APOB 3) PCSK9