Applied Pathophysiology: Genetic and Developmental Disorders Flashcards


Set Details Share
created 1 year ago by Lanaban07
12 views
updated 1 year ago by Lanaban07
Subjects:
pathophysiology
show moreless
Page to share:
Embed this setcancel
COPY
code changes based on your size selection
Size:
X
Show:

1

Autosomal Dominant

Mutation located on the autosome

Inheritance of a mutation involving one dominant allele results in expression of the trait

2

Autosomal Recessive

Mutation located on the autosome

Inheritance of a mutation involving two recessive alleles results in expression of the trait

Inheritance of a mutation involving one recessive allele results in expression in carrier status for the trait.

3

Sex-linked

Mutation located on the sex chromosomes

Gender difference in inheritance

  • Most are linked to the x chromosome
  • Males are more likely to be affected

4

Mitochondrial Gene Disorders

Related to energy production

Maternal inheritance

Not passed on by men

Heteroplasmy

5

Polygenic Disorders

Multiple alleles at different chromosome locations affect phenotype

Complex interaction of multiple factors

Environmental influences (height)

Less predictable pattern

Monosomy (Turner Syndrome)

Trisomy (Down syndrome)

6

Nondisjunction

Alteration in chromosome number

During second meiotic division the chromosome doesn't split into the two daughter cells. One cell may have the two daughter chromosomes and the other may have none. When fertilized the father's sperm can add a third chromosome (trisomy) or the empty cell will receive only the father's chromosome (monosomy)

7

Congenital Disorders

Diseases or abnormalities that are present at birth

8

Congenital Disorders- Environmental factors

Chemicals, hormones, drugs, pathogens, environmental agents, nutrition, and intrauterine environment, ionizing radiation, maternal nutrition can have detrimental effects on anatomic and physiologic development

9

Congenital Disorders- Organogenesis

Development of organs between 3 and 8 weeks of gestation

Enviornmental factors can play a role in this

10

Congenital Disorders- Teratogens

Pathogens, drugs, alcohol, and environmental chemicals can cause damage to organs, physical and cognitive development, and spontaneous abortion

11

Congenital Disorders- Maternal Infection

TORCH- Toxoplasmosis, Other (Hepatitis), Rubella, Cytomegalovirus, Herpes

12

Fetal Alcohol Syndrome (FAS)

Caused by continued consumption of alcohol throughout pregnancy

Cognitive impairment, physical disability, growth deficit

13

Prenatal Screening and Diagnosis

Screens for chromosomal abnormalities and genetic risks through maternal blood for down syndrome or neural tube defects.

Ultrasound is used to determine any physical abnormalities

Fetal cells, percutaneous blood sampling, and amniocentesis

14

Treatment Strategies for Genetic and Development Disorders

Assess literacy level

Provide information about rates of risk

Promote ability to make informed decisions

15

Huntington Disease

Defect in Huntington gene on chromosome 4. Genetic mutation accumulates to toxic levels which destroys nerve cells and causes brain atrophy

The gene causes a triplet cytosine, adenine, guanine (CAG)

Degeneration of the basal ganglia and cortical regions of the brain

Progressive degenerative neurologic disorder with an autosomal dominant inheritance pattern

16

Huntington Disease Manifestations

Movement, emotional, and cognitive impairment

Dyskinesia- difficulty in performing voluntary movements

Huntington's Chorea- dancelike movements. Rapid, involuntary, nonrepetitive movement of the face, trunk and limbs

Personality changes, loss of memory, emotionally labile, antisocial, impulsive

Manifestations begin by mid 40's

17

Huntington Disease Diagnosis

Family history. A parent has a 50% chance of passing it on

Physical exam

Mental, cognitive, and emotional evaluation

Genetic testing

Blood testing for repetitive CAG

CT, MRI, PET scans

18

Huntington Disease Treatment

No cure

Drugs for movement and psychiatric disorders

Occupational, physical, and speech therapies

Nutrition management

19

Sickle Cell Disease

Single gene mutation with autosomal recessive inheritance

Homozygous: disease phenotype

Heterozygous: carrier

Point mutation leading to altered structure of the beta chain of hemoglobin in RBC

Sickled shape, known as hemoglobin S (HbS)

This is an ischemia disorder, NOT PAIN

20

Sickle Cell Disease Manifestations

Jaundice- RBC's breakdown and release bile

Anemia- RBC's are broken down in the spleen (hemolysis)

Pain- ischemia to the joints and chest during times of stress or low O2

Organ damage- ischemia and short lifespan of RBC's causes insufficient nutrients to organs

Infection

Related to the proportion of HbS in the circulation

21

Sickle Cell Disease Diagnosis

Genetic screening

Hemoglobin electrophoresis

Determine proportion of hemoglobin types

CBC, UA, AST, ALT, BUN, Creatinine

22

Sickle Cell Disease Treatment

Treatment depends on symptoms

Meds to prevent infection- vaccinations, flu, Hep...

Avoidance of extreme temperatures

Reduce stress- emotional and physical

Hydroxyurea (DMARD) helps promote production of Hemoglobin F to promote RBC's

Maintain hydration

Treat pain and infections

Mediport for easy IV access for frequent blood draws, and IV fluid replacement

23

Down Syndrome

Alteration in autosome number

Trisomy of chromosome 21

Result of nondisjuncture or inherited translocation

24

Down Syndrome Manifestations

Mental delay

Facial features

Cardiac defects

GI malformations

Visual and hearing impairment

Thyroid dysfunction

Prone to leukemias- ALL

Deeper cry

25

Down Syndrome Diagnosis

History and physical exam

Prenatal diagnosis: nuchal translucency, Quadruple test (serum alfa-fetoprotein, unconjugated estradiol, hCG hormone, inhibin A), amniocentesis, anatomic anomalies, fetal karyotype

26

Down Syndrome Treatment

Promotion of maximal independence and quality of life

Physical, speech, and occupational therapy

Treatment of associated congenital disorders

27

Turner Syndrome

Alteration in sex chromosome number. Monosomy of chromosome X

Results in decreased life expectancy. Diabetes and heart disease

28

Turner Syndrome Manifestations

Manifestations depend on the time of nondisjuncture

Short stature, gonadal failure: delayed puberty, infertility; cardiac and kidney abnormalities, skeletal and soft tissue abnormalities, hearing loss, learning difficulties and social problems

29

Turner Syndrome Diagnosis

History and physical exam

Prenatal screening: hygroma on the back of the neck (fluid filled sac or sacs that form from an error in development of lymphatic structures), edema, short femur, narrow aortic arch

Karyotype and genetic testing

30

Turner Syndrome Treatment

Treatments depend on the symptoms

Assistance in socialization

Hormonal therapy

31

Neural Tube Defects

Developmental disorders during embryonic development

Birth defects involving nervous system tissues

Spina bifida

Anencephaly

32

Neural Tube Manifestations

Spina bifida- incomplete closure of vertebrae

  • without protrusion of meninges or spinal cord: spina bifida occulta
  • with protrusion of meninges: meningocele
  • With protrusion of meninges and spinal cord/nerve roots: myelomeningocele

33

Neural Tube Diagnosis

Physical exam

Prenatal screening: serum alpha-fetoprotein level, amniocentesis, ultrasound identification

34

Neural Tube Treatment

Spina bifida- surgical correction, supportive care

Prophylactic- FOLIC ACID!