Single Gene Disorders and Complex Inheritance

Question 1

What type of disorder is Marfan syndrome?

Answer 1

Disorder of connective tissues

Question 2

Where is the mutation in Marfan syndrome?

Answer 2

Chromosome 15- fibrillin I gene

Question 3

What are life threatening components of Marfan’s syndrome?

Answer 3

Cardiovascular lesions- aorta and valves

Question 4

What do individuals with Marfan’s syndrome look like?

Answer 4

Tall, slender, long appendages

Arachnodactyl (spider fingers)

Question 5

Where is the mutation in Huntington disease?

Answer 5

Chromosome 4 has abnormal number of CAG repeats

Question 6

What are signs of Huntington Disease?

Answer 6

Mental deterioration, involuntary appendage movement

Late acting lethal dominant

Question 7

In the most common form of albinisms, what is there a lack of?

Answer 7

Tyrosinase

Question 8

What are some things associated with albinism?

Answer 8

Risk of sunburn
Skin cancer
impaired vision
photosensitivity

Question 9

What are symptoms of phenylketonuria?

Answer 9

Irritabile, tremorous, slow developing retardation

affects nervous system

Question 10

Where does the excess phenylalanine diet show up?

Answer 10

Urine (musty odor)

Question 11

What is defective in cystic fibrosis?

Answer 11

chloride ion membrane transporter

Question 12

What is the most common single-gene disorder in Caucasians?

Answer 12

Cystic fibrosis

Question 13

Where is the mutation found in cystic fibrosis?

Answer 13

Chromosome 7

Question 14

What is hemophilia A due to?

Answer 14

Lack of Factor VIII

Question 15

What does a person with triplet repeat mutations (Fragile X) have?

Answer 15

CGG repeats; 230-400 repeats

Question 16

What amplifies the triplet repeat mutations (Fragile X syndrome)?

Answer 16

Oogensis

Question 17

How is mitochondrial genes passed?

Answer 17

Through the mother

Question 18

What do mitochondrial gene mutations code for?

Answer 18

Oxidative respiration enzymes

Question 19

What is Prader-Willi syndrome caused by?

Answer 19

Deletion on paternal 15

Question 20

What is Angelman Syndrome caused by?

Answer 20

Deletion on maternal 15

Question 21

In which syndrome do individuals laugh inappropriately?

Answer 21

Angelman Syndrome

Question 22

What disorders are where there are two or more mutant genes?

Answer 22

Polygenic disorders

Question 23

What is required for digenic retinitis pigmentosa?

Answer 23

2 rare mutations in 2 different unlinked genes which are part of the photoreceptor

Question 24

What are the three factors required for idiopathic cerebral vein thrombosis?

Answer 24

2 genetic (Missense mutation in clotting factor V, variation in 3' UTR of prothombin gene) 
1 environmental (oral contraceptives)

Question 25

What does Hirschsprung Disease cause?

Answer 25

Abnormality of parasympathetic innervation of gut; no peristalsis

Question 26

What creates type 1 diabetes?

Answer 26

Autoimmune destruction of Beta cells in pancreatic islands- no insulin production

Question 27

What locus is associated with type 1 DM?

Answer 27

MHC locus

HLA-DR3, HLA-DR4 loci

Question 28

What type plaques are present with Alzheimer’s Disease?

Answer 28

B-amyloid plaques and neurofibrillary tangles which destroy cortical tissue

Question 29

What is the genetic aspect of schizophrenia supported by?

Answer 29

Twin and family studies

Question 30

What disease is characterized by periods of mood elevation alternating with periods of depression?

Answer 30

Bipolar Disease