Genetic Disease

Question 1

Genetic disease

Answer 1

Permanent change in DNA sequence

Question 2

Types of mutations

Answer 2

Single gene mutations and chromosomal gene mutations

Question 3

Alleles

Answer 3

Different DNA sequences

Question 4

Locus

Answer 4

Specific site on the chromosome where an allele is located

Question 5

Homozygote

Answer 5

Matching alleles at the same loci on both chromosomes

Question 6

Heterozygote

Answer 6

Paired loci have different alleles

Question 7

Autosomal dom disease

Answer 7

First 22 chromosomes 
50% affected by disease 
No skipped generations
Males and females affected equally 
Homozygous usually have it the worst

Question 8

Marfan disease

Answer 8

Mutation in gene that codes for a collagen protein results in elastic collagen

Question 9

Huntingtons disease

Answer 9

Trinucleotide repeat disorder (CAGCAGCAG) causing brain cell death
Ex) dymentia

Question 10

Autosomal recessive disease

Answer 10

2 recessives

Question 11

Characteristics of pedigrees

Answer 11

Tend to cluster among siblings
Mating among cousins 
Aa: carrier
aa: disease
AA: no disease

Question 12

Cystic fibrosis (AR)

Answer 12

Mucous plugs obstruct the respiratory tract, pancreatic tract, and other organs

Question 13

Sickle cell anemia (AR)

Answer 13

Single base pair mutation

Changes in hemoglobin relating to hypoxic conditions

Question 14

X-linked recessive disease

Answer 14

Last 2 chromosomes (sex)
No male-male transmission
Males are more commonly affected
Skipped generations are common

Question 15

XX: no disease
XY: no disease
XX’: carrier because the body can just use one X
X’Y: has disease only has one infected X

Answer 15

K

Question 16

Hemophilia A (X)

Answer 16

Bleeding disorder caused by a clotting factor deficiency

Question 17

Duchenne Muscular Dystrophy

Answer 17

Mutation in the gene that codes for a protein found in skeletal muscles
Causes: loss of muscle tissue in childhood

Question 18

Chromosome disorders

Answer 18

Seen in 1/150 live births

Cause of 50% of miscarriages

Question 19

Down syndrome (CD)

Answer 19

Trisomy 21 (3 chromosome 21)
chromosomal nondisjunction responsible for 95% of cases

Question 20

Down syndrome clinical features

Answer 20

Developmental delays 
Distinct facial features
Heart disease
Risk of leukemia
Premature aging