Inheritance Patterns

Question 1

Shape of males in pedigree drawing

Answer 1

Square

Question 2

Shape of females in pedigree drawing

Answer 2

Circle

Question 3

In a pedigree drawing, what do partners have between them?

Answer 3

Partners have a line between them

Question 4

In a pedigree drawing, what do siblings have above them

Answer 4

Siblings have a line above them

Question 5

In a pedigree drawing, who are shaded?

Answer 5

People who are affected are shaded

Question 6

In a pedigree drawing, who have dots inside?

Answer 6

Carriers have dots inside

Question 7

In a pedigree drawing, what do double lines mean?

Answer 7

Are a consanguineous couple(Same blood)

Question 8

What does SB on a pedigree drawing mean?

Answer 8

Still born baby

Question 9

What does the diamond symbol in a pedigree drawing represent?

Answer 9

Means unknown sex

Question 10

What do small triangle symbols in a pedigree drawing represent?

Answer 10

Spontaneous abortion

Question 11

What does a triangle with a line going through it represent?

Answer 11

Represents therapeutic abortion

Question 12

What represents identical twins, non-identical twins?

Answer 12

Identical twins have diagonal lines and a line between them

Non identical twins have only diagonal lines

Question 13

What does a diamond with the letter P inside represent?

Answer 13

Represents someone who is pregnant of a child with an unknown sex

Question 14

What symbol represents no offspring?

Answer 14

SEARCH ONLINE

Question 15

In what form are autosomal dominant inheritance?

Answer 15

Clearly in heterozygous form

Question 16

How many generations are affected by autosomal dominant inheritance?

Answer 16

Multiple generations are affected by autosomal dominant inheritance

Question 17

What will most individuals with autosomal dominant inheritance have?

Answer 17

Most will have an affected parent

Question 18

What is the risk to offspring for autosomal dominant inheritance?

Answer 18

50% risk to offspring

Question 19

Characteristics of autosomal dominant inheritance

Answer 19

• Most individuals have an affected parent
• Males and females are equally likely to inherit
• An affected individuals siblings/children whom aren’t affected, do not carry the mutation and cannot pass it on to their offspring

Question 20

FEATURES OF AUTOSOMAL DOMINANT INHERITANCE

What is penetrance and incomplete penetrance?

Answer 20

Penetrance is the percentage of individuals who carry the mutation and develop symptoms of the disorder
-Many dominant disorders show age dependent penetrance
Incomplete penetrance is when you have the genotype, but not phenotypically expressed

Question 21

FEATURES OF AUTOSOMAL DOMINANT INHERITANCE

What is variable expressivity?

Answer 21

Variation in several symptoms of disorders between individuals with the same mutation

Question 22

FEATURES OF AUTOSOMAL DOMINANT INHERITANCE

What varies between autosomal dominant disorders?

Answer 22

De novo mutation rate varies considerably between autosomal disorder conditions

Question 23

FEATURES OF AUTOSOMAL DOMINANT INHERITANCE

What is somatic mosaicism?

Answer 23

It is when new mutation arises in early stages of embryogenesis
-Present in only some tissue/cells

Question 24

FEATURES OF AUTOSOMAL DOMINANT INHERITANCE

What is germ line mosaicism?

Answer 24

It is when new mutations arise during oogenesis or spermatogenesis
-Mutation present in variable proportion of gametes and can be transmitted to offspring

Question 25

FEATURES OF AUTOSOMAL DOMINANT INHERITANCE | What is anticipation?

Answer 25

Worsening of disease severity in successive generations | -Characteristically occurs in triplet repeat disorders

Question 26

In what form is autosomal recessive inheritance?

Answer 26

Clearly in homozygous form

Question 27

Who aren't affected by autosomal recessive inheritance?

Answer 27

Carriers aren't affected

Question 28

What sexes are affected by autosomal recessive inheritance?

Answer 28

Both sexes affected

Question 29

How many generations are affected by autosomal recessive inheritance?

Answer 29

Usually one generation affected

Question 30

What may be a factor of autosomal recessive inheritance?

Answer 30

May be consanguinity

Question 31

What are compound heterozygotes?

Answer 31

-2 mutations in the same gene however these mutations are different

Question 32

What is a homozygote?

Answer 32

-2 mutations in the same gene however these mutations are identical

Question 33

What are the features of autosomal recessive inheritance?

Answer 33

- Trait often found in clusters of siblings | - All offspring of affected person are obligate carriers

Question 34

Chromosomes in men and women

Answer 34

Men-XY | Women-XX

Question 35

What are the affects on BOTH genders of X-linked inheritance?(Recessive)

Answer 35

- Women are carriers and are unaffected | - No male to male transmission

Question 36

What are the affects on BOTH genders of X-linked inheritance?(Dominant)

Answer 36

- Women are affected | - Males are more severely affected

Question 37

What type of genes are never passed from father to son?

Answer 37

X-linked genes never passed from father to son

Question 38

In X-linked recessive inheritance, who are the obligate carriers?

Answer 38

All daughters of affected males are obligate carriers

Question 39

In X-linked recessive inheritance, what do children of carrier females have a chance of inheriting mutant alleles?

Answer 39

Children of carrier females have a 50% chance of inheriting mutant alleles

Question 40

What is skewed X-inactivation in X-linked recessive inheritance?

Answer 40

Normally the majority of genes on one of a women's X chromosome are inactivated

Question 41

Who are manifesting carriers?

Answer 41

Some women who have symptoms in x-linked recessive conditions?

Question 42

Y linked inheritance

Answer 42

Always and only passed through fathers to sons

Question 43

What is a mutation?

Answer 43

Change in genetic material

Question 44

What do a pathogenic mutation result in?

Answer 44

Results in an alteration of the function of the gene product and can cause disease

Question 45

What is a silent mutation?

Answer 45

A base change has no change in the amino acid