3.4 genetics 2

Question 1

3 types of inheritance

Answer 1

autosomal dominant, autosomal recessive, sex linked

Question 2

who has the trait in autosomal dominant diseases?

Answer 2

heterozygous

Question 3

what is variability? where can it be seen?

Answer 3

different expression of trait based on the amount of expression, heterozygous individuals for autosomal dominant

Question 4

who has the trait in autosomal recessive diseases?

Answer 4

homozygous recessive individuals (heterozygous does not show the trait)

Question 5

sex linked alleles can be found on what chromosome?

Answer 5

X

Question 6

Females with one allele of a sex linked disease are _____ but if they have male children that inherit this allele they will _____

Answer 6

carriers, have the trait

Question 7

what can you deduce from this pedigree?

Answer 7

-dad is affected, so are kids (2/3)
- both M and F, doesn’t skip a generation
-most likely autosomal dominant

Question 8

how does dentinogenesis imperfecta show?

Answer 8

translucent brown teeth (teeth can vary gray to blue to brown)
blue-ish sclera

Question 9

what is dentinogenesis imperfecta a feature of?

Answer 9

osteogenesis imperfecta

Question 10

dentinogenesis imperfecta is caused by a defect in the _____ gene

Answer 10

COL1 A1/2

Question 11

what is cleidrocranial dysplasia?

Answer 11

• autosomal dominant condition
• dysplasia of bone/teeth
• small facial bones, low nasal bridge, hypertelorism, deafness
  -can put shoulders together

Question 12

in Cleidocranial dysplasia the primary dentition appears ______ and is frequently incomplete

Answer 12

late

Question 13

what is secondary dentition like in Cleidocranial dysplaia?

Answer 13

late, malaligned, some teeth malformed/hypoplastic, supernumerary teeth
-enamel hypoplasia

Question 14

what causes cleidocranial dysplasia

Answer 14

mutations of CBFA1

Question 15

what is crouzons syndrome?

Answer 15

a genetic syndrome in which the seams of the skull fuse abnormally

Question 16

what is brachycephaly?

Answer 16

appearance of short/broad head

Question 17

_______ is bulging eyes due to shallow eye sockets after early fusion of surrounding bones

Answer 17

Exophthalmos

Question 18

_____ is greater than normal distance between the eyes

Answer 18

hypertelorism

Question 19

what is the name for a beak-like nose?

Answer 19

psittichorhina

Question 20

hypoplastic maxilla

Answer 20

not long/wide enough

Question 21

how can crouzons syndrome affect teeth/bite

Answer 21

• narrow/high arched palate
• posterior lingual cross-bite
• hypodontia (missing)
  -increased spacing

Question 22

what is Crouzons syndrome caused by?

Answer 22

mutations in FGFR2 gene

Question 23

what is oligodontia?

Answer 23

missing teeth

Question 24

two known causes of oligodontia?

Answer 24

PAX9, MSX1

Question 25

What can you tell about this Oligodontia pedigree?

Answer 25

-M and F affected
- shows in every generation
-autosomal dominant

Question 26

what is the defect in Exon 4 of PAX9 that causes oligodontia?

Answer 26

inserted Cytosine leads to frame shift mutation (this changes primary protein structure and alters its function)

Question 27

there is another loss of function mutation in PAX9 that can cause____

Answer 27

tooth agenesis

Question 28

what is Primary failure to erupt?

Answer 28

incomplete tooth eruption despite the presence of a clear eruption pathway

Question 29

can ortho treatment help PFE?

Answer 29

no! because there is no eruptive abilty

Question 30

what issue in PTH1R can cause PFE?

Answer 30

G>A substitution, this negates an RNA splice and causes an abnormal protein

Question 31

who is a historical example of a Class III malocclusion?

Answer 31

Charles II of spain

Question 32

what caused the Hapsburg Jaw?

Answer 32

incest

Question 33

What ethnicities is Short Root anomaly seen in more?

Answer 33

mexican, japanese descent