Genetics/Stress Flashcards
maternal or paternal copy of autosomes is inactivated and remains in this inactive state in all of the somatic cells
Genetic Imprinting
deletion of about 4 million base pairs of the long arm of chromosome 15 when inherited from the FATHER
Prader-Willis Syndrome
deletion of about 4 million base pairs of the long arm of chromosome 15 when inherited from the MOTHER
Angelman Syndrome
Features of Syndrome: short stature hypotonia small hands & feet obesity mild-moderate intellectual disability
Prader-Willis Syndrome
Features of Syndrome: severe intellectual ability seizures ataxic gait bouts of uncontrolled laughter
Angelman Syndrome
Prevalence of Prader-Willis & Angelman
1 in 15,000
the deletions that cause ______ & _______ are indistinguishable at the DNA sequence level and affect the same group of genes
Angelman & Prader-Willis Syndrome
state of affairs arising when a person relates to situations in certain ways
Stress
the optimal steady-state
Homeostasis
physiologic systems are dynamic and capable of changing set-points after exposure to stress
Allostasis
individualized cumulative effects of stressors that exist in people’s lives and influence their physiologic responses
Allostatic Load
exaggerated pathophysiologic responses to stress
Allostatic Overload
Mediators & Biomarkers of __________:
glucocorticoid
catecholmines
proinflammatory cytokines
Allostatic Overload
catecholamines
epinephrine & norepinephrine
part of the interdependent processes system that moderates stress
coping
nonspecific response to noxious stimuli
General Adaptation Syndrome (GAS)
stage of GAS:
CNS arousied and body defenses are mobilized
“fight or flight”
Alarm Stage
stage of GAS:
mobilization contributes to “fight or flight”
Resistance/Adaptation Stage
stage of GAS:
continuous stress causes progressive breakdown of compensatory mechanisms (acquired adaptations)
breakdown of homeostasis
marks onset of certain diseases
Exhaustion Stage
diseases that are onset by the exhaustion stage of GAS
Diseases of Adaptation
first physical components activated by stressor alarming
Hypothalamus & Sympathetic Nervous System
hormones responsible for starting Resistance/Adaptation Stage of GAS
epinephrine, norepinephrine, cortisol
results of continued stress and unsuccessful adaptation
impaired immune response
heart failure
kidney failure
death
physiological response derived from psychologic stressors
Reactive Response
physiological responses developed in anticipation of disruption of homeostasis
Anticipatory Response
physiological stress response produced by learned associations of dangerous situations
Conditional Response
feeling of general unpleasant arousal after exposure to life events that manifest as physiologic, emotional, cognitive, and behavioral changes
Psychological Distress
places affected individual at risk for immunological deficits
Depression associated with adverse life events
increases the risk of cardiovascular disease, Type 2 DM, cancer + other somatic disorders
childhood adversity (abuse, neglect, dysfunctional family, low SES)
disease with no carrier status
Huntington
study of how the consciousness (psycho) & the brain/spinal cord (neuro) and the body’s defenses against infection and abnormal cell division (immunology) interact
Psychoneuroimmunology (PNI)
46, XY
Normal Male
46, XX
Normal Female
number of autosomes
44
49, XXXXY
48, XXXY
47, XXY
Klinefelter
47, XX
Trisomy
47, XX, 21
Down Syndrome
45, X
Turner
92, XX
Tetraploidy
hormone secreted from the locus ceruleus that causes emotional responses to stress
norepinephrine
stress hormones released by the sympathetic nervous system
neuropeptide Y (NPY)
norepinephrine
epinephrine
action of posterior pituitary in response to a stressor
increased ADH/vasopressin
water retention
action of anterior pituitary in response to stressor
increased ACTH to adrenal cortex
hormone released by adrenal cortex in response to stressor
cortisol
hormone responsible for:
vasoconstriction
vascular growth factor
angiogenic factor
neuropeptide Y (NPY)
hormone responsible for: BP increase pupil dilation piloerection (goosebumps) sweating arteriole smooth muscle contraction
norephinephrine
hormone responsible for: bronchodilation increased lipolysis increased cardiac output pancreas effects liver effectsx
epinephrine
epinephrine effect on pancreas
decreased insulin
decreased glucose uptake in skeletal muscle/adipose tissue
increased glucagon
increased glucogenesis
epinephrine effect on liver
decreased glycogenn synthesis
increased glycogenolysis
decreased insulin + increased glucagon in pancreas lead to …
increased blood glucose
decreased glycogen synthesis + increased glycogenolysis in liver lead to…
increased blood glucose
hormone responsible for: BP increase cardiac output increase decrease of luteinizing hormones, estradiol, testosterone amino acid in blood increase increased extremity lipolysis lymphoid tissue atrophy face/trunk lypogenesis
cortisol
results of atrophy of lymphoid tissue
antiinflammatory or proinflammatory
immunosuppression or enhanced humoral immunity
hormone released by the adrenal medulla
epinephrine
hormone released by the adrenal cortex
cortisol
increased blood flow
increased glucose metabolism
catecholamine effect on brain
increased rate and force of contraction
peripheral vasoconstriction
catecholamine effect on CV system
bronchodilation
catecholamine effect on pulmonary system
increased glycogenolysis increased contraction increased dilation of muscle vasculature decreased glucose uptake and utilization -decreased insulin release
catecholamine effect on skeletal muscle
increased glucose production
increased glycogenesis
catecholamine effect on liver
increased lipolysis
decreased glucose uptake
catecholamine effect on adipose tissue
decreased blood flow
catecholamine effect on skin
decreased protein synthesis
decreased smooth muscle contraction
increased renin release
increased gastrointestinal sphincter tone
catecholamine effect on GI & GU systems
decreased # of natural killer cells
catecholamine effect on lymphoid tissue
inhibition or stimulation of activity
catecholamine effect on macrophages
disorders caused by prolonged cortisol elevation
GI ulcers sarcopenia osteoporosis Type 2 DM cancer high cholesterol Alzheimer
Turner Syndrome is caused by ________.
nondisjunction during meiosis
adaptive physiological response to stress
allostasis
chance of exhibiting phenotype
penetrance
exact allele composition for a single-gene trait
genotype
observed expression of a single-gene trait
phenotype
Recessive single-gen traits are only expressed when…
person is homozygous for the two gene alleles
Genotype and phenotype are ALWAYS the same for…
recessive traits
Dominant single-gene traits are _______ expressed.
always
cells contain fewer or more chormosomes than normal
aneuploidy
more than 2 sets of ALL chromosomes
polyploidy
actual # of chromosomes present in a single-cell nucleus @ mitosis
ploidy
organized arrangement of all the chromosomes in the cell during metaphase of mitosis
Karyotype
Normal Human Ploidy
46 total chromosomes
23 pairs
alternative form or variation of a gene at a specific location
allele
normal karyotype
euploid
too few chromosomes
monosomy
too many chromosomes on one pair
trisomy
formation of sperm
spermatogenesis
formation of ova
oogenesis
Spermatogenesis converts diploid precursor germ cells into…
haploid sperm
Oogenesis converts diploid precursor germ cells into…
haploid ova
Spermatogenesis begins at…
puberty
Spermatogenesis stops when?
never
Spermatogenesis process is…
continuous
Oogenesis begins at…
fetal life
Oogenesis stops when?
menopause
Oogenesis process is…
cyclical
Completion of Meiosis I & II in spermatogenesis takes…
days - weeks
Completion of Meiosis I & II in ootogenesis takes…
years after fertilization
Prophase I of spermatogenesis takes…
hours - days
Prophase I of oogenesis takes…
years
In spermatogenesis, one diploid precursor cell can result in formation of…
4 haploid sperm capable of fertilizing mature ovum
In oogenesis, one diploid precursor cell can result in formation of…
1 haploid ovum capable of being fertilized by mature sperm + up to 3 haploid polar bodies
Equal distribution of cytoplasm during meiosis occurs in…
spermatogenesis
cell division that reduces the chromosome number and has multiple stages/steps
meiosis
male/female distribution of autosomal dominant traits
equal
male/female distribution of autosomal recessive traits
equal
male/female distribution of sex-linked recessive traits
greater in males (maybe only males)
carrier status of autosomal dominant traits
none
carrier status of autosomal recessive traits
carriers with one affected allele may express the trait
carrier status of sex-linked recessive traits
50% risk of mom passing to offspring
100% risk of dad passing to females
0% risk of dad passing to males
generation appearance of autosomal dominant traits
seen in all generations
generation appearance of autosomal recessive traits
allelle may be in family for many generations w/o expression
generation appearance of sex-linked recessive traits
if no males born, could be many generations w/o expression
risk of inheritance of autosomal dominant traits
heterozygous 50% chance
homozygous 50% chance
risk of inheritance of autosomal recessive traits
2 affected parents 100% chance
family members w/ trait 25% chance
may not appear in all generations
risk of inheritance of sex-linked recessive traits
no females born to dads 0%
no females born to non-carrier moms 0%
Autosomal Dominant Traits/Disorders
A & B blood types free earlobes widow's peak Huntington Dx Marfan Syndrome Neurofibromatosis Rhett Syndrome
Autosomal Recessive Traits/Disorders
attached earlobes O type blood Cystic Fibrosis Albinism Sickle Cell Disease PKU
Sex-Linked Recessive Disorders
Duchenne Muscular Dystrophy
Fragile X Syndrome
Hemophilia
occurence of gene expression when it’s present
penetrance
percentage of population with gene mutation who express the trait
penetrance rate
degree to which a gene is expressed in persons with Autosomal Dominant gene
expressivity
X-linked recessive disorders are increased in males because…
males onle have 1 allele for every X chromosome gene so there’s no balancing allele on Y chromosome
means any X-linked allele in males is expressed as dominant
hemizygosity
X linked recessive disorders have _______ expression in males
dominant
X linked recessive disorders have _______ expression in females
recessive
type of tranmission that occurs when several genes are working together or during a combination of genes and environment
complex disease transmission
type of transmission that occurs with dominant or recessive traits
Mendelian pattern transmission
in Mendelian pattern transmission, gene expression is based on __________
probability
In complex disease transmission, gene variants ______ or ________ from phenotype.
add or subtract
changes that happen on or above the genome expression
epigenome
epigenetic modification occurs without….
DNA sequence changes
Causes of Epigenetic Modification
development environmental chemical exposure drugs aging diet
Results of Epigenetic Modification
cancer
autoimmune dx
mental disorders
diabetes
chemical process that silences the genes from one parent- turns off expression of the gene(s)
methylation
process that tends to diminish the positive charfe of histones, reducing their binding strength to negatively charged DNA and making the DNA more accessible for transcription
histone acetylation
process that increases or decreases the strength of bonding between DNA & histones
histone methylation
positively charged proteins around which negatively charged DNA molecules are wound that facilitate compaction of DNA into the nucleus
histones
gene components that alter the activity of oncogenes and tumor-suppressor genes
micro RNA (miRNA)
mother’s or father’s copy of autosomal gene is inactivated and remains in this inactivated state in all the somatic cells of the individual
imprinting
imprinting disease in which a deletion of about 4 million base pairs of the long arm of chromosome 15 are deleted inherited from the father
Prader-Willi Syndrome
imprinting disease in which a deletion of about 4 million base pairs of the long arm of chromosome 15 are deleted inherited from the mother
Angelman Syndrome
Symptoms of Prader-Willi Syndrom
truncal obesity
small hands/feet
inverted V-shaped upper lip
Symptoms of Angelman Syndrome
characteristic posture
ataxic gait
bouts of uncontrolled laughter
inheritance of an extra copy of each chromosome resultsing in 69 chromosomes per cell
triploidy
cells having 92 chromosomes
tetrapoloidy
inheritance of an extra copy of one chromosome
trisomy
pair of chromosomes fail to separate properly during meiosis
nondisjunction
only one copy of chromosome in a diploid cell
monosomy
presence of single X chromosome and no homologous X or Y chromosome
Turner’s Syndrome
Turner’s Syndrome affect only…
females
females w/ Turner’s Syndrorme are sterile because…
gonadal streaks are present instead of ovaries
Features of Syndrome: short stature neck webbing wide nipples coarctation of the aorta nb webbed feet sparse hair normal IQ
Turner’s Syndrome
Most cases of Turner’s syndrome are caused by the loss of the _______ X chromosome
paternal
doubling of chromosomal material
duplication
broken chromosomes and loss of DNA
deletion
condition caused by deletion of part of the short arm of chromosome 15
Cri du Chat
Syndrome Features: male appearance sterile gynecomastia small testes sparse body hair high pitched voice tall stature mental deficits
Klinefelter
condition where 2/3 of the cases are caused by nondisjunction of X chromosomes
Klinefelter
prevalence of Klinefelter syndrome
1 in 1000 male births
a condition in which 2 or more different karyotypes are consistently present in one individual; some cells have normal karyotype and some have normal karyotype
mosaicism
prevalence of Down Syndrome
1 in 800 births
Syndrome Features: low IQ short stature low nasal bridge epicanthal folds protruding tongue flat/low ears hypotonia CHD decreased ability to fight URI Alzheimer Dx
Down Syndrome
condition where 90% of cases are caused by nondisjunction + 3% caused by translocations
Down Syndrome
percentage of Down Syndrome cases caused by nondisjunction in egg cell
90-95%
percentage of Down Syndrome cases caused by paternal nondisjunction
5-10%
Trisomy 13 is _______ Syndrome
Patau
prevalence of Patau Syndrome
1 in 10,000 births
Syndrome Features: extra digits digit fusion abnormal iris small/close eyes organ rotation brain fusion deafness vision problems seizures apnea
Patau Syndrome (Trisomy 13)
Trisomy 18 is _______ Syndrome
Edward
prevalence of Edward Syndrome
1 in 3,000 births
Edward Syndrome is more prevalent in ______
females
Syndrome Features: same as Trisomy 13 + strawberry shaped head low ears clenched fist overlapping fingers palmar crease arched fingerprints Rocker bottom feet heart defects kidney problems esophogeal atresia omphalocele inguinal/umbilical hernias brain cysts
Edward Syndrome (Trisomy 18)