Autosomal Recessive

Question 1

Angelman syndrome involves active _______ from the _______ and inactive __________ from the ________

Answer 1

SNRPN from father

UBE3A from mother

Question 2

Symptoms of hurler syndrome

Answer 2

Progressive intellectual disability, skeletal abnormalities, short stature, corneal clouding, and course facial features

Question 3

Diseases with delayed age of onset can reduce

Answer 3

Natural selection against the disease

Question 4

Example of a heterogenous disease

Answer 4

Osteogenesis imperfecta col1A1 gene on chromosome 17 or chromosome 7

Question 5

Hereditary hemochromatosis treatment

Answer 5

Bloodletting

Question 6

The loss of SNRPN can result in:

Answer 6

Prader-Willi syndrome

Question 7

The hardy-Weinberg equation is used when ____________ is unavailable

Answer 7

Family (individual) history is available

Question 8

Hurler syndrome is a ______________ disease

Answer 8

Autosomal recessive

Question 9

P^2 =

Answer 9

Homozygous frequency

Question 10

Q^2=

Answer 10

Homozygous frequency

Question 11

It is estimated that each person carries five recessive genes in the heterozygous form that would result in lethal phenotype if they were present in a homozygous state. This is called:

Answer 11

Genetic burden

Question 12

Treatment of hurler syndrome

Answer 12

Targeted enzyme replacement therapy, hematopoietic stem cell transplant

Question 13

Penetrance versus variable expression

Answer 13

Penetrance = did inherent, did NOT express

Variable expression = did inherent, did express in some way

Question 14

Imprinting involves:

Answer 14

Methylation of specific nucleotides in the DNA and generally transcriptionally silences the gene

Question 15

When an individual consists of more than one distinct population in eggs or sperm is called

Answer 15

Germline mosaicism

Question 16

What type of disorder is hurler syndrome?

Answer 16

Mucopolysacharidosis, a lysosomal storage disorder

Question 17

The hardy-weinberg principle states that the frequency of ______ in a population is mathematically related to the frequency of _________ in a population

Answer 17

Alleles

Genotypes

Question 18

HFE protein function

Answer 18

Detecting the amount of iron in the body and regulates the production of hepcidin, which influences iron absorption and release

Question 19

A heterogeneous disease is one where mutations:

Answer 19

At different gene loci can produce the same disease phenotype

Question 20

The hardy-weinberg principle equation is used most commonly for determining the likelihood that an individual is

Answer 20

Carrying a particular recessive disease allele

Question 21

Reproduction among family members is referred to as:

Answer 21

Consanguinity

Question 22

How could one with the genotype of retinoblastoma (RB1) not present with the disease?

Answer 22

Reduced penetrance- manifesting a retinoblastoma usually requires a second mutation that inactivated the other RB1 gene allele, 10% of those with the mutant genotype will not develop the disease

Question 23

Anticipation in inheritance involves:

Answer 23

An earlier age of onset and/or more severe expression in more recent generations of a pedigree due to repeat expansions

Question 24

Most common cause of death among those with untreated hemochromatosis

Answer 24

Cardiac failure

Question 25

2pq =

Answer 25

Heterozygous frequency

Question 26

Example of a disease that can display anticipation

Answer 26

Myotonic dystrophy Fragile X Huntington disease

Question 27

Gene that Hurler syndrome effects

Answer 27

A-L-iduronidase | A= alpha

Question 28

Hereditary Hemochromatosis specific gene mutation

Answer 28

Single missense mutation

Question 29

Myotonic dystrophy specific gene mutation

Answer 29

DMPK gene- expansion of a trinucleotide repeat (CTG) in the 3’ untranslated portion of the gene

Question 30

Hereditary Hemochromatosis is a _______________ disease

Answer 30

Autosomal recessive

Question 31

The cause of anticipation is believed to be due to

Answer 31

Slippage of DNA polymerase during DNA replication leading to trinucleotide expansion

Question 32

Germline mosaicism involves a mutation:

Answer 32

Affected all or some of the germ cells in the ovaries or testes, but not enough of their somatic tissue to produce a phenotype in that parents

Question 33

Hereditary Hemochromatosis effects which gene

Answer 33

HFE (high iron)

Question 34

A recessive disease can be passed ________ through generations

Answer 34

Silently

Question 35

Founder Effect:

Answer 35

Intermarriage within small communities can lead to many individuals carrying the same recessive mutations from the founders

Question 36

UBE3A gene function

Answer 36

Ubiquitin-mediated protein degradation, strongly in the brain (cognition)

Question 37

Penetrate refers to:

Answer 37

The proportion of individuals carrying a particular genotype that also express the associated phenotype

Question 38

Prader-Willi syndrome involves active _________ from the ________ and inactive _________ from the _________

Answer 38

UBE3A from the mother | SNRPN from the father

Question 39

_________ is present more often in pedigrees involving autosomal recessive diseases, especially rare diseased

Answer 39

Consanguinity

Question 40

Why are males more commonly affected in hereditary hemochromatosis than females?

Answer 40

Delayed onset of disease (~30 years old), delayed further in women due to menstruation blood loss

Question 41

Hurler syndome results in the

Answer 41

Buildup of glycosaminoglycan in lysosomes

Question 42

On average, _____ of the offspring of the mating between two heterozygous carriers will be affected with the autosomal recessive disease

Answer 42

1/4

Question 43

Examples of pleiotropy

Answer 43

Cystic fibrosis, Marfan syndrome, NF1

Question 44

Loss of UBE3A gene is associated with

Answer 44

Angelman syndrome

Question 45

A _______ gene is one that exerts its effects on multiple aspects of physiology or anatomy

Answer 45

Pleiotropic

Question 46

When does re-imprinting occur?

Answer 46

During opogenesis or spermatogenesis

Question 47

Many recessive diseases involves mutations in genes that encode for

Answer 47

Enzymes

Question 48

Osteogenesis imperfecta can be a __________ disease

Answer 48

Germline mosaic autosomal dominant

Question 49

When two or more siblings are affected with an autosomal DOMINANT disease, but both parents are unaffected, ________ should be considered

Answer 49

Germline mosaicism of one of the parents

Question 50

SNRPN gene function

Answer 50

Small nuclear riboprotein expressed in the brain