Genetic Disease

Question 1

How many protein-encoding genes are in the human genome?

Answer 1

19,000

Question 2

T/F: Permanent change in the germ cells can be inherited.

Answer 2

True

Question 3

Permanent DNA damage in the _______ cells may result in a tumor or developmental abnormality.

Answer 3

Somatic

Question 4

Autosomal dominant, autosomal recessive, and sex-linked disorders are all __________ disorders.

Answer 4

Mendelian

Question 5

What are cytogenetic disorders?

Answer 5

Involve chromosomal aberrations: autosomes or sex chromosomes

Question 6

T/F: Different mutations at different spots on a gene will always have unique manifestations.

Answer 6

FALSE

Question 7

Huntington’s disease is an autosomal __________ disorder.

Answer 7

Dominant

Question 8

What is incomplete penetrance?

Answer 8

Person has a mutant gene but doesn’t or only partially extremes it phenotypically

Question 9

What is variable expressively?

Answer 9

Expression can be identified in all affected persons, but to differing extents

Question 10

What is a new or “de novo” mutation?

Answer 10

Neither parent affected/no family history

Question 11

What is an example of an autosomal dominant disease withe variable expressivity?

Answer 11

Neurofibromatosis

Question 12

What is the largest group of Mendelian disorders?

Answer 12

Autosomal recessive

Question 13

Many AR conditions are ________ defects, leading to __________ dysfunction.

Answer 13

Enzyme; metabolic

Question 14

What one trait may be linked to the Y chromosome?

Answer 14

Hairy ears

NO DISEASES

Question 15

T/F: In x-linked disorders, women will more often express the disease.

Answer 15

FALSE

Women have another X-chromosome to protect them.

Question 16

What is a common example of an X-linked disorder?

Answer 16

Hemophilia A

Question 17

Describe lyonizations and unfavorable lyonizations?

Answer 17

Lyonization: one of the X chromosomes from the mom will be inactivated (normally results in mixture of active maternal and paternal X chromosomes)

Unfavorable lyonizations: inactivation of high number of normal X chromosomes may result in X-linked disease expression in a heterozygous female

Question 18

Marian syndrome is an ___ disorder involving in a mutation with the ______ gene.

Answer 18

AD; FBN1

Question 19

What are some complications of Marfan syndrome?

Answer 19

Aortic aneurysm and dissection

Question 20

Which disease causes a problem with collagen synthesis? These patients may be circus performers due to their stretchable skin.

Answer 20

Ehlers-Danlos Syndromes

Question 21

Familial hypercholesterolemia is due to a genetic disorder of the ____ receptor.

Answer 21

LDL

Question 22

Cystic fibrosis is caused by a genetic disorder of the _______ channel protein.

Answer 22

chloride

Question 23

Familial hypercholesterolemia is seen in how many people?

Answer 23

1 in 500

Question 24

Patients will develop early atherosclerosis, especially if they are homozygous, for which disease?

Answer 24

Familial hypercholesterolemia

Question 25

A 20 year old patient dies of myocardial infarction due to an atherosclerosis. Which disease lead to this?

Answer 25

Homozygous for familial hypercholesterolemia

Question 26

Phenylketonuria, galactosemia, and lysosomal storage diseases are all caused by mutations in _______ proteins.

Answer 26

Enzyme

Question 27

Phenylketonuria is an ____ disorder. It will often cause ______________ by 6 months of birth.

Answer 27

AR; mental retardation

Question 28

How would you treat phenylketonuria?

Answer 28

Restrict diet of phenylalanine

Question 29

Accumulation of large insoluble molecules in macrophages leads to neuronal damage and other neural problems in a young child. What is the disorder?

Answer 29

Lysosomal storage disease - mutated enzyme

Question 30

Mucopolysaccharide storage disease is a type of _________ storage disease?

Answer 30

Lysosomal

Question 31

Which disease is caused by a deficiency of alpha-L-iduronidase?

Answer 31

Hurler Disease

Question 32

________ is an X-linked disease caused by a deficiency of L-iduronate sulfatase.

Answer 32

Hunter

Question 33

T/F: Hunter disease often has a much better outlook than Hurler disease.

Answer 33

TRUE

Question 34

How many newborns has a chromosomal abnormality?

Answer 34

1 in 200

Question 35

A normal chromosome count (2 x 23 = 46) is termed _________?

Answer 35

Euploid

Question 36

An increase in chromosome count that is a multiple of that normally seen (i.e. 3 x 23) is termed __________ and generally results in abortion.

Answer 36

polyploidy

Question 37

Any number that is not an exact multiple of the normal chromosome count is termed _______.

Answer 37

Aneuploidy

Question 38

Having one extra chromosome is termed _________.

Answer 38

Trisomy

Question 39

Having one less chromosome is termed _________>

Answer 39

Monosomy

Question 40

____________ is transfer of a part of one chromosome to another nonhomologous chromosome.

Answer 40

Translocation

Question 41

When fragments are exchanged between two chromosomes it is termed _________ translocation.

Answer 41

Reciprocal

Question 42

_________ is the loss of a portion of a chromosome.

Answer 42

Deletion

Question 43

__________ is when the chromosome breaks in two points, then the released fragment is reunited after a complete turnaround.

Answer 43

Inversion

Question 44

What is trisomy 21?

Answer 44

Down Syndrome

Question 45

What are the odds of having a child with Down Syndrome if a mother is over 45 years old?

Answer 45

1 in 25

Question 46

What is Klinefelter syndrome?

Answer 46

Sex chromosome disorder where the patient is phenotypically male but genotype is XXY

Question 47

Female hypogonadism is a major symptom of ___________.

Answer 47

Turner syndrome

Question 48

What are some prenatal indications for genetic analysis?

Answer 48

1. Mothers age >40 2. Parent is carrier 3. Hx of previous child with abnormality

Question 49

Postnatal indications for genetic analysis?

Answer 49

1. Multiple congenital abnormalities 2. Infertility 3. Multiple miscarriages 4. Unexplained developmental problems 5. Suspected aneuploidy

Question 50

What is the major symptom of Klinefelter syndrome?

Answer 50

Hypogonadism and sterility

Question 51

What is a dental related symptom of Klinefelter syndrome?

Answer 51

Taurodontism = enlarged pulp

Question 52

What is different about the genotype of someone with Turner syndrome?

Answer 52

Only has one X chromosome

Question 53

What are some symptoms of Turner syndrome?

Answer 53

1. Short 2. Shield-like chest 3. High arched palate 4. Cardiovascular problems 5. No secondary sex characteristics

Question 54

What is a point mutation and example of disease from point mutation?

Answer 54

Single nucleotide base. Sickle cell

Question 55

What is a frame shift mutation?

Answer 55

Insertion or deletion of 1 or 2 base pairs, altering the reading frame of DNA

Question 56

What is a trinucleotide repeat mutation and an example of a disease?

Answer 56

Amplification of sequence of 3 nucleotides. Fragile X syndrome

Question 57

What are epigenetic changes?

Answer 57

Modulation of gene expression without altering DNA sequence

Question 58

What happens when promoter regions are methylated? This is an example of what?

Answer 58

Makes them inaccessible to RNA polymerase = reduced expression. Epigenetics

Question 59

When is the age of onset typically for AR diseases?

Answer 59

Early in life

Question 60

T/F: Complete penetrance is common in autosomal recessive disease.

Answer 60

True

Question 61

What may cause a heterozygous female to demonstrate full expression of a X-linked disease?

Answer 61

Unfavorable lyonization

Question 62

Who would be affected by an X-linked dominant disorder?

Answer 62

Heterozygous, homozygous, and hemizygous

Question 63

What is an example of an X-linked dominant disorder?

Answer 63

Oral-Facial-Digital syndrome

Question 64

What are some examples of Lysosomal Storage diseases?

Answer 64

1. Tay-sachs 2. Niemann-Pick 3. Gaucher 4. Mucopolysaccharidoses

Question 65

What are three ways to diagnose genetic diseases?

Answer 65

1. Fluorescence in situ hybridization (FISH) - recognize specific sequences 2. Comparative genomic hybridization - compare to normal DNA 3. Molecular diagnosis (PCR, restrictions enzyme, fluorescence)