Genetics

Question 1

Permanent changes in DNA can affect ______ cells or ______ cells

Answer 1

Germ cells

Somatic cells

Question 2

Germ cell mutations

Answer 2

Can be inherited

Question 3

Somatic cell mutations may result in

Answer 3

Tumor or developmental abnormality

Question 4

Point mutation

Answer 4

single base substituted

Question 5

Frameshift

Answer 5

Insertion/deletion of 1-2 bases

Question 6

Trinucleotide repeat

Answer 6

Amplification of a 3 nucleotide sequence

Question 7

Epigenetic Changes

Answer 7

Methylation of cytosine residues

Question 8

Alterations in Non-coding RNAs

Answer 8

MicroRNAs

Long non-coding RNAs

Question 9

Mendelian Disorders

Answer 9

Autosomal Dom
Autosomal Rec
Sex linked

Question 10

Disorders with mulifactoral inheritance

Answer 10

Polygenic

Question 11

Cytogenetic disorders

Answer 11

Chromosomal aberrations

Autosomes
Sex chromosomes

Question 12

What disorders are visible in Karotypes

Answer 12

Cytogenetic disorders

Question 13

Mendelian Disroders

Answer 13

Single Gene defects

Question 14

Genetic alteration often results in

Answer 14

Production of abnormal protein which can alter phenotype

Question 15

Because genes are comprised of many base pairs a mutation can occur at different places within the genet yet

Answer 15

Produce essentially the same phenotypic alterations

Question 16

Mutations of a gene locus may affect

Answer 16

One or both chromosomes in a pair

Question 17

Reduced penetrance

Answer 17

If a person has a mutant gene but doesn’t or only partially expresses it phenotypically

Question 18

Variable expressivity

Answer 18

If expression can be identified in all affected persons but to differing extents

Question 19

If neither parented affected/no family history

Answer 19

De novo mutation

Question 20

Neurofibromatosis penetrance

Answer 20

100%

Nearly everyone with this will show evidence

Highly variable expressivity

Question 21

Largest group of Mendelian disorders

Answer 21

Autosomal recessive disorders

Question 22

Autosomal recessive ____ of offspring affect _____ are carriers

Answer 22

25%

50%

Question 23

Lyonization

Answer 23

16 days post conception

• most of one X chromosome is inactivated
• replaced with Barr body

Question 24

Lyonization females are genetically

Answer 24

Mosaic-they have a mixture of active paternal and maternal X

Question 25

Marfan Syndrome

Answer 25

A. Dom. 1:5000

Question 26

Marfan Syndrome mutation of

Answer 26

FBN1 gene Resulting in abnormal fibrillin necessary for elastic fiber production

Question 27

Marfan Syndrome symptoms

Answer 27

``` Tall, thin body Abnormally long legs Arachnodactlyly Dislocation of lens of the eye Aortic aneurysms and dissection ```

Question 28

Ehlers- Danilo’s Syndrome problem with

Answer 28

Collagen synthesis among 30 distinct types of collagen

Question 29

Is Ehlers Danlos Syndrome dominant or recessive

Answer 29

Both forms possible

Question 30

How many types of collagen have issues with Ehlers Danlos Syndrome

Answer 30

30 distinct types

Question 31

Skin fragility, loose joints, and issues with wound healing

Answer 31

Ehlers Danlos Syndrome

Question 32

Diseases caused by mutations in Genes encoding receptor proteins or channels

Answer 32

Familial hypercholesterolemia Cystic fibrosis

Question 33

Where is the mutation for familial hypercholesterolemia

Answer 33

LDL receptor

Question 34

Where is the mutation for Cystic fibrosis

Answer 34

Chloride channel protein

Question 35

Familial hypercholesterolemia is autosomal

Answer 35

Dominant

Question 36

Familial hypercholesterolemia | Frequency

Answer 36

1:500

Question 37

Familial hypercholesterolemia mutation of the LDL receptor results in

Answer 37

Impaired metabolism and increased LDL cholesterol in the plasma

Question 38

Homozygotes for Familial hypercholesterolemia have _____LDL levels

Answer 38

5x normal | Heteroz 2-3x

Question 39

Diseases caused by mutations in enzyme proteins

Answer 39

Phenylketonuria Galactosemia Lysosomal storage diseases

Question 40

Phenylketonuria autosomal_____

Answer 40

Recessive

Question 41

Phenylketonuria frequency

Answer 41

1: 10,000 white infants

Question 42

Phenylketonuria is the lack of______ which leads to _____________

Answer 42

Phenylalanine hydroxylase which leads to hyperphenlalanamia and PKU

Question 43

Phenylketonuria infants are _____ at birth

Answer 43

Normal at birth but elevated phenylalanine levels impair brain development Mental retardation by 6 months of age

Question 44

Phenylketonuria treatment

Answer 44

Dietary restricting phenylalanine Screening is mandatory in the US

Question 45

Storage Diseases

Answer 45

AR Accumulation of large insoluble molecules in macrophages leads to heptaosplenomegaly

Question 46

Storage diseases effects on CNS

Answer 46

Leads to neuronal damage, mental retardation and or early death

Question 47

Lysosomal Storage Diseases

Answer 47

Tray-Sachs Disease Neumann-Pick Disease Gaucher Disease Mucopolysaccharidoses

Question 48

Mucopolysaccharide Storage diseases are autosomal _____

Answer 48

Recessive

Question 49

Mucopolysaccharide Type I : Hurler Disease | Caused by

Answer 49

Deficiency of alpha-L-iduronidase

Question 50

Hurler disease without treatment

Answer 50

6-10 years

Question 51

Hurler disease Treatment

Answer 51

Bone Marrow Transplant Enzyme replacement may improve outlook but not all aspects of the disease are corrected

Question 52

Hunter Syndrome

Answer 52

X linked deficiency of L-iduronate sulfatase

Question 53

Hunter syndrome is different from hurler, how?

Answer 53

Absence of corneal clouding and milder clinical course, but otherwise similar to Hurler syndrome

Question 54

Frequency of newborns with chromosome abnormality

Answer 54

1:200

Question 55

_____% of 1st trimester abortion due to chromosome abnormalities

Answer 55

50%

Question 56

Euploid

Answer 56

Normal chromosome count

Question 57

Polyploidy

Answer 57

Increased chromosome count that is a multiple of that normally seen 3x23 4x23

Question 58

Aneuploidy

Answer 58

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

Question 59

Trisomy

Answer 59

Extra chromosome

Question 60

Monopoly

Answer 60

Absence of a chromosome

Question 61

Translocation

Answer 61

The transfer of a part of one chromosome to another nonhomologous chromosome

Question 62

Reciprocal translocation

Answer 62

Fragments are exchanged between two chromosomes

Question 63

Deletion

Answer 63

Loss of a portion of a chromosome

Question 64

Inversion

Answer 64

Chromosome breaks in two points, the the released fragment is reunited after a complete turnaround

Question 65

Trisomy 21

Answer 65

Down syndrome Most common chromosomal disorder

Question 66

Trisomy 21 associated with

Answer 66

Advanced maternal age

Question 67

Trisomy 21 due to

Answer 67

Meritocracy non disjunction of chromosome 21 during ovum formation

Question 68

Cytogenetic disorders involving sex chromosomes

Answer 68

Klinefleter Turner

Question 69

Klinefelter Syndrome

Answer 69

XXY Phenotypically males

Question 70

Klinefleter phenotype

Answer 70

Increased length of lower limbs Reduced body hair Gynecomastia Hypogonadism

Question 71

Turner Syndrome

Answer 71

45X ``` Short Webbed neck Shield chest High arch Cardio issues Failure to develop secondary sex ```

Question 72

Parental Indication for analysis

Answer 72

Mother 34+ A parent is a carrier of translocation or X linked Previous child with issue

Question 73

Post natal indications for genetic analysis

Answer 73

``` Multiple congenial anomalies Unexplained retardation or delay Suspected aneuploidy Suspected sex chromosomal abnormality Infertility Multiple spontaneous abortions ```