genetic disease

Question 1

what are the three types of gene mutation

Answer 1

genome mutation
chromosomal mutation
gene variant

Question 2

what is gene mutation?

Answer 2

loss or gain of an entire chromosome

Question 3

what is chromosomal mutation

Answer 3

alteration of a segment of chromosomes

Question 4

what is gene variant

Answer 4

partial or complete deletion of a gene

Question 5

state the order of specificity of genes

Answer 5

genome -> chromosomes long chain of DNA -> genes (segments of DNA)

Question 6

What is the typical human genome

Answer 6

44 chromosomes with 23 pairs of chromosomes. 22 pairs will be autosomal and 1 pair of sex chromosomes.

Question 7

what is meant by hereditary or familiar genes

Answer 7

condition is derived form parents due to a genetic mutation

Question 8

what is meant by congenital genes

Answer 8

condition is appears at birth. maybe hereditary or can be due to exposure at birth

Question 9

what are the 5 types of inheritance patterns

Answer 9

1. autosomal dominant
2. autosomal recessive
3. x-linked recessive
4. chromosomal
5. mixed inheritance

Question 10

break down the meaning of autosomal dominant

Answer 10

autosomal- the gene in question is located on one of the 44 chromosomes. Not a sex chromosome
dominant- a single copy of the mutated gene is enough to express the gene phenotypically.

Question 11

what are the three examples for autosomal dominant

Answer 11

1. familiar hypercholesterolemia
2. marfan syndrome
3. osteogenesis imperfecta

Question 12

what is the mutation of familiar hypercholesterolemia

Answer 12

low density lipoprotein (LDL)
receptor mutation will result in impaired uptake of cholesterol into the cells.

Question 13

what are the clinical manifestations of familiar hypercholesterolemia

Answer 13

• elevated blood cholesterol levels
  -atherosclerosis resulting in cardiovascular disease
• death before the age of 30 due to uncontrolled CVD.

Question 14

What is the mutation in Marfans syndrome

Answer 14

fibrillar-1 gene on the 15 chromosome

fibrillar provides support for production of elastic fibers

Question 15

what are the clinical manifestations for marfans syndrome

Answer 15

1. skeletal: long arms, legs, and fingers
2. Eye: Bilateral dislocation of the lens
3. cardiovascular: aortic root dilation, leading to aortic insufficiency, myxomatous mitral valve, ascending thoracic aortic aneurysm, aortic dissection

Question 16

what is the percent breakdown for the presentation of osteogenesis imperfecta?

Answer 16

autosomal dominat 80% of the time
20% is autosomal recessive

Question 17

what does heterogeneous mean

Answer 17

refers to collagen respresentation in osteogenesis imperfecta is very different.

Question 18

what is meant by pleiotropic

Answer 18

one gene will influence two phenotypic traits

Question 19

what is the mutation in osteogenesis imperfecta?

Answer 19

90% of cases are caused by a mutation of the COL1A1 or COL1A2 genes

Question 20

what two genes encode for type 1 collagen?

Answer 20

COL1A1 and COL1A2

Question 21

How will an X-ray detect osteogenesis imperfecta?

Answer 21

mild osteopenia

Question 22

describe the pathophysiology of osteogenesis imperfecta?

Answer 22

disease in type 1 collagen
- a major extracellular protein in the body dermis

can effect: connective tissues int he organs, GI, and Vascular system and bones

Question 23

what are the S/S of type 1 osteogenesis imperfecta?

Answer 23

fractures- that will decrease after puberty
blue sclera
in adults a short stature

most mild form of OI

Question 24

What are genetic determinats noticed in type 1 osteogenesis imperfecta?

Answer 24

25% are from new cases
75% are from autosomal dominant

Question 25

what are the S/S of type 2 osteogenesis imperfecta?

Answer 25

Most severe form will be present before birth 1. multiple fractures 2. bone deformities 3. significant fragillity of non bony connective tissue 4. blue sclara 5.short limbs 6. small chest 7. soft skull typically results in death in infancy

Question 26

what is the hallmark charateristic of type 2 osteogenesis imperfecta?

Answer 26

hips will be externally rotated and abducted "froggie legs"

Question 27

what might an xray find in a patient with type 2 osteogenesis imperfecta?

Answer 27

isolated islands of mineralization in the skull and beaded appearance in the ribs

Question 28

what is the genetic ties to type 2 osteogenesis imperfecta?

Answer 28

NONE all new dominant mutation

Question 29

what are the S/S of type 3 osteogenesis imperfecta?

Answer 29

patients show at birth: 1. progressive bony deformities 2. multiple fractures 3. blue sclera may loose ability to walk by early adulthood

Question 30

nearly all case of type 3 osteogenesis imperfecta are due to?

Answer 30

dominant mutation

Question 31

What are the S/S of type 4 osteogenesis imperfecta?

Answer 31

postnatal fractures that range from type 1 to type 3 children will fracture later in learning to walk moderate growth retardation bony deformities blue sclera very short long bones

Question 32

what is the distinguishing factor between type 1 and type 4 osteogenesis imperfecta?

Answer 32

type four involves moderate to severe growth retardation

Question 33

what is the order for osteogenesis imperfecta?

Answer 33

type 1< type 4< type 3< type 2

Question 34

What is meant by autosomal recessive?

Answer 34

autosomal- not a sex chromosome recessive- a single copy of the mutated gene is carrier but nor expressed; two copies of the mutated gene are required for phenotypic expression

Question 35

what is the given example for autosomal recessive?

Answer 35

cystic fibrosis

Question 36

What is the mutation involved with cystic fibrosis?

Answer 36

Cystic Fibrosis transmembrane conductance regulator gene on chromosome 7

Question 37

what is the epidemiology of cystic fibrosis

Answer 37

1 in 3500 live births white predominantly

Question 38

what are the clinical manifestations of cystic fibrosis?

Answer 38

1. fibrosis of pancreas 2. recurrent pulmonary infections- pneumonia 3. chronic bronchittis, bronchiectasis 4. meconium ileus 5. billiary cirrhosis 6. infertility in males think and sticky mucus

Question 39

what is infertility in males with CF second to

Answer 39

missing vas deferens

Question 40

what is thick and stickey mucus in CF secondary to

Answer 40

absence of chloride on cell surface

Question 41

Biliary cirrhosis in CF leads to

Answer 41

impaired absorption of the fat soluble vitamins A,D,E, and K

Question 42

what is meant by X-linked recessive

Answer 42

genetic conditions associated with mutations in genes on an X chromosome

Question 43

what is the example of X-linked recessive?

Answer 43

Duchenne Muscular Dystrophy

Question 44

what is the mutation noticed in Duchenne Muscular Dystrophy

Answer 44

Dsytrophin gene at Xp21

Question 45

what is the epidemiology in Duchenne Muscular Dystrophy

Answer 45

1 in 3000 infants profound in male predominance female carriers of the disease are asymptomatic

Question 46

what is the clinical course of Duchenne Muscular Dystrophy

Answer 46

disease will manifest by 5 years assoated weakness will create immobility in teen years usual death by 20 or 30s. cardiomyopathy and non progressive cognitive abnormalities are also fairly common

Question 47

what are the signs and symptoms of Duchenne Muscular Dystrophy

Answer 47

- weakness in pelvis first- delayed ability to walk - Psuedohypertrophy- enlargement of calf muscles due to fat - Gower maneuver- use of hands to rise to standing up - muscle atrophy and weakness - wheelchair dependent by the second decade of life - Death due to respiratory insuffecency and cardiac failure

Question 48

what is meant by chromosomal inheritance mutations

Answer 48

mutation of a large segment or entire chromosome

Question 49

what are the examples for a chromosomal inheritance pattern

Answer 49

downsyndrome and trisomy 18

Question 50

what is the mutation for down sydrome

Answer 50

extra copy of the 21st chromosome

Question 51

what are clinical manifestations of down sydrome

Answer 51

1. intellectual disability 2. characteristic facial features 3. hypotonia 4. protruding tongue 5. congenital heart disease

Question 52

what is the epidemiology of down syndrome

Answer 52

1 in 700 newborns

Question 53

what is the mutation in Edwards syndrome

Answer 53

trisomy 18

Question 54

what are the clinical manifestations of Edwards / trisomy 18?

Answer 54

1. heart / organ defects 2. small and abnormally shaped head, small jaw and mouth 3. clenched fists with overlapping fingers

Question 55

what might an individual with Edwards present at birth weight wise?

Answer 55

slow growth and low in birth weight

Question 56

what is life expectancy for trisomy 18

Answer 56

most will die within their first month due to medical problems only 5 to 10% of children will live past 5 years

Question 57

What is the epidemiology of trisomy 18

Answer 57

every 1 in 5,000 live births

Question 58

What is meant by a genetic condition with mixed inheritance patterns

Answer 58

depending on the gene involved the inheritance pattern can be any

Question 59

whats the disease example for a genetic condition with mixed inheritance patterns

Answer 59

Ehlers-Danlos sydrome

Question 60

what is up with the mutation in Ehlers-Danlos sydrome

Answer 60

it is contributed to changes in at least 20 genes

Question 61

what is Ehlers-Danlos sydrome

Answer 61

Hereditary collegen disorder in which there is articular hypermobility, dermal hyperelasticity, and widespread tissue fragility

Question 62

what is the clinical prevalence of Ehlers-Danlos sydrome

Answer 62

1 in 5,000 worldwide

Question 63

what are the clinical manifestations of Ehlers-Danlos sydrome

Answer 63

- hyperextensible skin - fragile tissue - poor wound healing - joint hyper mobility - increased propensity for joint subluxation - muscle weakness - delayed motor development - fatigue - gait defects - chronic pain

Question 64

what are the pt implications of Ehlers-Danlos sydrome

Answer 64

1. joint stability- low resitance and high repatition 2. assistive device for loading relief 3. bracing to promote joint stability (decreasing subluxation) 4. pain management