L1 Genetics

Question 1

Missense mutation
What is it
Example

Answer 1

Point mutation,

Sickle cell anemia

Question 2

Frameshift mutation

Answer 2

insertion or deletion of one or two base pairs

Question 3

Trinucleotide repeat mutation
What is it
Example

Answer 3

Amplification of sequence of 3 nucleotides

Fragile X syndrome

Question 4

Epigenetic changes

Answer 4

modulation of gene expression w/o altered DNA sequence

Question 5

Alterations in non coding RNAs

Answer 5

Micro-RNAs inhibit translation of target messenger RNAs into corresponding proteins

Question 6

Autosomal dominant disorder
Characteristics
Example

Answer 6

Outward physical changes
Delayed age of onset
Huntingtons

Question 7

Autosomal recessive disorders

Characteristics

Answer 7

Enzyme deficiencies
Presents early in life
Uniform/complete penetrnace

Question 8

Lyonization

Answer 8

16 days after conception 75% of one X chromosome is randomly inactivated

Question 9

X linked dominant disease example

Answer 9

Oral-Facial-Digital syndrome (OFD) Type I

Question 10

Marfan syndrom
Type of disorder
Affects
Gene

Answer 10

Autsomal dominant disorder of CT–>abnormal fibrillin

FBN1

Question 11

Marfan Syndrome

Phenotype

Answer 11

Tall, thin, long arms, fingers
Dislocation of eye lens
Aortic aneurysm, dissection leading to heart failure and aortic rupture

Question 12

Ehler-Danlos Syndrome
Affects
Symptoms

Answer 12

Affects collagen
Hyperextensible skin/joints
Delayed wound healing
Rupture of colon
Hernias, large arteries

Question 13

Familial hypercholesterolemia

What is it

Answer 13

Mutation in gene for LDL receptor
Results in impaired metabolism and increase LDL
Leading to skin Xanthomas and premature atherosclerosis

Question 14

Phenylketonuria
Type of disorder
What does it affect

Answer 14

Autosomal recessive for gene encoding enzymes

Lack Phenylalanin hydroxylase leading to hyperphenylalaninemia and PKU

Question 15

Phenylketonuria

Who does it affect

Answer 15

1 in 10,000 whites

Normal at birth, mental retardation by 6

Question 16

Lysosomal storage diseases
Type of transmission
Who does it affect

Answer 16

Autosomal recessive

Infants and young

Question 17

Normal chromosomes
Multiple of normal
Non-Multiple
Extra
Absence

Answer 17

Euploid
Polyploid-->abortion
Aneuploid
Trisomy
Monosomy

Question 18

Reciprocal transolocation

Answer 18

Transfer of one part of chromosome to another non homologous chromosome

Question 19

Cause of down syndrom

Answer 19

Meiotic non disjunction of chromosome 21 during formation in ovum

Question 20

Klinefelter syndrome
What is it
Dental syndome

Answer 20

XXY hypogonadism

Taurodontism

Question 21

Turner syndrome
What is it
Symptoms

Answer 21

Absence of one X chromosome

Short, shield chest, High Palate, cardio malformation, lack of secondary sex char.

Question 22

Molecular diagnosis steps

Answer 22

PCR to amplify
Compare
Restriction enzymes w/ electrophoresis
Compare
Fluorescent labels
PCR

Question 23

Comparative Genomic Hybridization
What is it
What does it identify

Answer 23

Different dyes attached to large segments of DNA followed by hybridization
Identifies gene amplification or deletion