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learning objectives for patho chapter 6

Terms in this set (75)

______: present at, and usually before, birth.
congenital
______: one or two more different forms of a gene that can occupy a particular locus of a chromosome.
allele
_____: the entire genetic constitution of an individual, as determined by the particular combination and location of the genes on the chromosomes; or the alleles present at one or more sites on homologous chromosomes.
genotype
_______: the complex physical, biochemical, and physiologic makeup of an individual, as determined by the interaction of both genetic makeup and environmental factors.
-physical characteristics
phenotype
______: having two different alleles at corresponding loci on homologous chromosomes.
Heterozygous
_____: having two identical alleles at corresponding loci on homologous chromosomes.
Homozygous
_____: one of several, or many, forms of an organism or cell.
polymorph
_______ are copies of a gene
alleles
if all your copies of a gene are alike, you are _______
Homozygous
if all your copies of a gene differ then you're _______
heterozygous
if you are heterozygous for a recessive trait and do not show it, you are a ______
carrier
if you only have one copy of a gene, you are _______
hemizygous
______: is the physical site or location of a specific gene on a chromosome.
gene locus
_______: is a change in one or more genes. some _____ can lead to genetic disorders or illnesses
gene mutation
a gene is said to be _______ if more than one allele occupies that gene's locus within a population. in addition to having more than one allele at a specific locus, each allele must also occur in the population at a rate of at least 1% to generally be considered _______.
polymorphic
a discontinuous genetic variation that results in different forms or types of individuals among the members of a single species.
polymorphic
_______: refers to the likelihood that a clinical condition will occur when a particular genotype is present. for adult-onset disease, ______ is usually described by the individual carrier's age, sex, and organ site.
gene penetrance
the appearance in a phenotype of a characteristic or effect attributed to a particular gene.
-the process by which possession of a gene leads to the appearance in the phenotype of the corresponding character.
gene expression
______ is the cell cycle process in which nongerm cells are replicated
mitosis
non germ cells are
everything but your sex cells
______ is limited in replicating germ cells and takes place only one time in a cell line!
-results in formation of gametes or reproductive cells (ovum and sperm)
meiosis
______: genes "turn on" and "turn off"
gene expression
-gene expression-
-________: something turns a gene on
induction
-gene expression-
-________: something turns a gene off
repression
-gene expression-
-________: manner in which a gene is expressed in the phenotype; may be mild to severe.
expressitivity
-gene expression-
-________: ability of a gene to express its function; 75% ________ means 75% of people with that genotype present with a recognizable phenotype.

ex: we gave drop of blood looked at your genes and you have purple eaters' disease
1 out of 100 will bite people.
penetrance
-gene expressivity-
will a person phenotype determine how they look if it is a RECESSIVE gene?
no
-gene expressivity-
will a person's phenotype determine how they look if it is a DOMINANT gene?
yes
________ gene has to have one copy from mom and one from dad
recessive
________ gene has to have at least one copy to be shown.
dominant
__________: single-gene pattern of inheritance; includes autosomal dominant and recessive traits that are transmitted to offspring in a predictable manner.
mendelian inheritance
-gene interactions-
many genes could affect one trait: _______
polygenic
-gene interactions-
both multiple genes and the environment could affect one trait: _______
multifactorial
-gene interactions-
one gene could mask the effect of another: ________
epistasis
-gene interactions-
one gene might depend on another: _________
complementary
-gene interactions-
two genes together might create a new phenotype:_________
collaborative
-genes are found on chromosomes-
if found on X and Y chromosomes: _________
if found on other chromosomes: ________
sex-linked
autosomal
normal female genotype is _________
X, X genotype (female)
normal male genotype is _________
X, Y male
_______: could be boy, girl that has this defect all other pairs of chromosomes
autosomal
_______ are copies of a gene
alleles
- transmitted from an affected parent to offspring regardless of gender
-50% chance of transmission-- ex. mom has disorder it is a ____ _____ disorder. mom has 1 gene of it you have a 50/50% chance of transmission
- unaffected (don't carry disorder; not effective) do not pass on the disorder
- delayed onset
- examples: marfan syndrome and neurofibromatosis
autosomal dominant
-autosomal dominant-
____ _______
- approx 75% family origin, rest spontaneous mutations.
-mutation on CHROMOSOME 15!!!!
- disorder of connective tissue results in elastin and collagen defects.
-affects the eyes, skeleton, and cardiovascular system; may be all systems or just one. wide range of presentations.
- long thin body; spider fingers; chest/back deformities; retinal detachment.
-loose, lax joints.
-risk of aortic rupture and dissection
-diagnosis: history, physical examination, skin biopsy (presence of fibrillin), genetic testing
- no cure; treatment is palliative; close follow-up for cardiac problems.
marfan syndrome
- autosomal dominant: ________-
-neurogenic tumors
- a defect on CHROMOSOME 17 OR 22; defect in tumor suppressor gene
-two forms:
- _____-______- subcutaneous lesions, cafe-au-lait spots (at least 6 at birth), freckles, scoliosis, erosive bone defects, and nervous system tumors; may have seizures or learning problems
- _____-______- less common; tumors of the acoustic nerve; HA, hearing loss, tinnitus; asymptomatic for the first 15 years; worse with oral contraceptives; problems w/swimming.
- treatment
- palliative removal of tumors.
neurofibromatosis
- type 1
-type 2
-_____ _____ ______-
- rare disorders
-both members of gene pair are affected
-affects both genders
- 1/4 will be affected; 1/2 will be carriers
-early onset
-usually caused by a deficient enzyme.
-increased risk with consanguineous mating (sex with close kin!)
- examples: PKU and Tay-Sachs
autosomal recessive disorders
- autosomal recessive: ___________ (______)-
- ______ (_________): metabolic disorder
- mutation on CHROMOSOME 12 leads to an error in converting phenylalanine to tyrosine; high levels of phenylalanine are toxic.
+ disfunction of enzyme happens
+mental disorder
+because of their diet they now have mental disorders
+you have a home birth and don't get the baby checked this can lead to the baby developing a mental disability
-appear normal at birth then fails to meet milestones
-progressive neurological decline
-if untreated, can lead to MR
-diagnosis: serum phenylamine at 3 days old
-treatment: avoid high protein food; limited amounts of starches
- they are trying some products that may be block absorption.
autosomal recessive: Phenylketonuria
PKU what foods to avoid
- because the amount of phenylalanine adults can safely eat is so low, it's crucial they avoid all ______-______ foods, including: list some off ____________________________________________________________________________________________________________________________________________________________
-children and adults should avoid foods, including many _____________________________________________________________________________________________________________________________________________________________________
-adults and children with PKU also have to limit the portions of lower protein foods, such as;
_____,_______,__________
high-protein
-milk, eggs, cheese, nuts, soybeans, chicken
-steak and other beef products, pork, fish
-chocolate candy; peas, deer

- diet sodas, and medications made with aspartame (NutraSweet, Equal). aspartame, found in many artificial sweeteners, releases phenylalanine when digested.
- fruits, vegetables, deserts
- autosomal recessive: ________ ______ _____-
- types of lysomal storage disease
-deficiency of absence of hexosaminidase a necessary to metabolize (chemical process in the body to turn food into energy, new growth, and waste products) certain lipids
-lipids accumulate, destroying and demyelinating nerve cells, especially brain and retinas.
-nerve cell destruction leads to a progressive mental and motor deterioration
-appears normal at birth, then the infant has progressive weakness, flaccidity, decreased attentiveness, and misses developmental milestones.
-progresses to seizures, muscular rigidity, and blindness
-usually fatal by 4-5 years old; no cure
-genetic counseling is suggested
-most are of Eastern European Ashkenazi Jewish decent

- you can't catch this disease
-your not getting proper neurological signals
- need to worry about brain
- muscles will become weak
- baby is floppy not exertive they are not listening to cues
- baby can die

- get genetic testing
- most disorders are created when people produce in a small group (everyone mating including children)
Tay-Sachs Disease
- sex- linked disorders are almost always ____-_____
-think about it...... Everyone has a x chromosome
x,x= female X,Y= male
-males have 50% chance of getting disorder from their mother
-females have a 50% chance of being carriers
- all daughters of affected males will be carriers, but none of their sones
example: glucose-6-phosphate dehydrogenase deficiency, hemophilia A, X-linked agammaglobulinemia
x-linked disorders
-single-gene disorders with atypical patterns of inheritance: _-
______ _____ ____: long repeated sequence of three nucleotides.
- abnormality of X chromosome: seen as discontinuity of staining or constriction in long arm of X chromosome.
- most common form of inherited intellectual disability...
- associated with a single trinucleotide gene sequence on the x chromosome
- lack of protein necessary for neural tube development
-S/Sx: large, long face with; large mandible, large, everted ears, mitral valve, prolapse, mental retardation, learning disabilities, hyperextensible joints, and behavioral issues.
- most distinctive feature (present in 90% of boys) is large testicles.
-because girls have two X chromosomes, they have relatively normal cognitive development.
- significant because mental retardation may be in carrier females and about 20% of males with gene or normal!
-no cure; treatment is supportive
fragile X Syndrome
which of the following statements is true about an individual who is a carrier for the recessive cystic fibrosis (CF) gene?
A. Homozygous; suffers from CF
B. Homozygous; does not suffer from CF
C. Heterozygous; suffers from CF
D. Heterozygous; does not suffer from CF
D. Heterozygous; does not suffer from CF

RATIONAL: if an individual is a carrier, they are heterozygous for the recessive trait (Because the trait is recessive)
-Scenario-
- a young man's father died of Bragada Syndrome...
- Unexplained sudden death
- due to mutation in the gene from the Na+ channel in cardiac muscle
- autosomal dominant trait
- his mother is alive and healthy
- both grandmothers are alive and healthy

question:
what is the son's chance of having the disease?
moms alleles b b
///////
dads alleles

b bb bb

B Bb Bb

- Bruganda syndrom has only a 12.5% penetrance
- what does this mean for the young man whose father died of it?
- a 12.5% penetrance means he inherited the dominant genetic disorder from an affected parent but has only a 12.5 % chance of expressing the disorder. However, he can still transmit the gene to his descendants.
-structural chromosomal abnormalities: _______ _____-
- breakage and rearrangement- just in a single chromosome
-Deletion
-Inversion
- Isochromosome formation
- Ring formation
- Translocation
chromosomal damage
_______: loss of one or more nucleotides from a segment of DNA.
Deletion
_______: A condition in which a chromosome segment is clipped out, turned upside down, and reinserted back into the chromosome. A chromosome ________ can be inherited from one or both parents, or it may be a mutation that appears in a child whose family has no history of chromosome inversion.
inversion
_______: structural chromosomal abnormality that results in an aberrant metacentric chromosome
isochromosome formation
________: is an aberrant chromosome whose ends have fused together to form a ring
ring formation
______: is a type of chromosomal abnormality in which a chromosome breaks and a portion of it reattaches to a different chromosome.
translocation
which type of chromosome alteration generally results in
normal offspring?
A. deletion
B. inversion
C. Translocation
D. ring formation
translocation
-chromosomal Disorders: ____ ____ ____ ____-
- ______: mitotic errors in early development gives rise to two or more cell lines with distinctive karyotypes
- ________: a change in chromosome number. can occur in autosomes or sex chromosomes (X,Y)
-failure of the chromosomes to separate=________
- _________: only one member of a pair. if autosomes, usually fatal to fetus
- ______: a variety of triosimes involve autosomal chromosomes (13, 18, 21, 22)
- ____ _____ most common trisomy
alterations in chromosome duplication
-mocaicism
-aneuploidy
- nondisjunction
-monosomy
-trisomy
-down syndrome
-Down syndrome: _____ ___-
- risk increase with maternal age
- caused from nondisjunction during meiosis
-S/Sx: small square head, upward slant of the eyes, small low set ears, fat pad on the back of the neck, open, mouth with protruding Toung, simian crease, and varying degrees of mental retardation.
trisomy 21
- also associated with congenital heart defects, ocular issues, leukemia, respiratory complications
diagnosis: maternal screening including amniocentesis, hormone levels, four-dimensional ultrasound
treatment: symptomatic and supportive
down's syndrome: trisomy 21
- _____ _____:_____ ___-
-deletion of all or part of an X
- no Y chromosome, so female
- S/Sx: gonadal streaks instead of ovaries, short stature, increased weight, webbing of the neck, small lower jaw, drooping eyelids, small fingernails, and widely spaced nipples.
- also associated with coarctation of the aorta, vision issues, hearing loss, renal abnormalities, infertility, and increased risk on infections.
-no mental retardation presents
-diagnosis: history, physical examination, and chromosomal testing
-treatment: estrogen and growth hormones.
turner's syndrome: Monosomy X
-____ _____: _____ _-
- one or more extra X chromosomes with the presence of the Y
-male appearance
- often undetected
-S/Sx: gynecomastia, small testis and penis, tall stature, increased weight, and sparse body hair.
-also associated with learning disabilities, behavioral problems, sexual dysfunction, pulmonary disease, varicose veins, osteoporosis, and breast cancer
-treatment: testosterone

EX: that one dude from sophomore year :)
Klinefelter's syndrome: Trisomy X
-environmental causes for congenital disorders: ____ ____ _____-
- developing embryo is subject to many nongenic influences.
-physiologic status of the mother; hormones, health, nutrition, drugs, smoking, infections, radiation
- READ: RADIATION, ENVIRONMENTAL CHEMICALS AND DRUGS MEDICATIONS AND ILLICIT DRUGS.
- embryo is vulnerable during organogenesis (day 15 to day 60)
- ________: an environmental agent that produces abnormalities during embryonic or fetal development.
- important to know drug pregnancy's risk categories.
-___ ____ ____; folic acid deficiency; infectious agents- this can happen is you're not immunized
period of vulnerability
- teratogen
-fetal alcohol syndrome
-_____ ____ ____-
- physical, behavioral, cognitive abnormalities resulting from maternal alcohol consumption. from minor to full syndrome.
-alcohol is a lipid soluble. passes freely across the placenta
-______ that affects fetus throughout pregnancy
- growth retardation; neurologic problems; skull/ facial deformity; small eyes; thin upper lip; flat midface and philtrum more prominent as infant develops. (lots of behavioral problems in school)
Diagnosis: three of the following 1) 3 facial abnormalities, 2) growth deficits (<10th percentile), 3) CNS abnormalities head circumference <10th, global cognitive problems, motor functioning delays, problem with attention or hyperactivity.
- don't know how much ETOH causes problems, but binge drinking though to be particularly significant.
fetal alcohol syndrome
-______ ____ ____-
- deficiency can cause neural tube defects (anencephaly, spina bifida, encephalocele)
-all women of childbearing age should receive 400 mcg of folic acid every day. esp if family history of previously affected pregnancy.
- all cereals are fortified with folic acid in us
- should also include folate-rich foods: orange juice, dark leafy green vegetables, legumes.
folic acid deficiency
- infectious agents: TORCHES-
many microorganisms cross the placenta.
acronyms TORCHES
T= _________: often transmitted by cats facies when you are pregnant should not change cat litter because this could cross over and effect developing fetus.
toxoplasmosis
O= ________ get immunization! (chicken pox lives in body forever) feels awfuls immune system can't fight off really MMR
other (varicella zoster, listeriosis, leptospirosis)
R= _______ alot of kids aren't up to date on immunizations it can mess up brain and body have loss of function
rubella
C= _________ located in dirt (no immunizations) don't let pregnant females be around it.
cytomegalovirus
H= ________ ____ ____ ___ high risk pregnancy your body can lose sight loose brain function
herpes simplex type 2
E= _______ being around people with mono while pregnant
Esptein-Barr
S= ______/______: can eat at brain you need to ger v-potassium shot to preserve your brain function.
1.brain does not develop
2. brain too small, water on brain, neurological problems
syphilis and ZIKA
1.,2 goes with ZIKA
describe the three types of pf single-gene disorder and give an example of a syndrome, condition, or disorder that would associate with the type?
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