FDN Facts Flashcards
Essential Fxns of mitochondria
Biosynthesis of: heme, a.a, n.t., steroid hormones… ATP synthesis, oxidation of fatty acids, apoptotic cell death
Does mitochondrial protein encoded more by nuclear genome or mitochondrial genome?
95% nuclear genome synthesized in cytosol, 13 mitochondrial protein (for ETC), large and small rRNAs/tRNAs made in mitochondria matrix encoded by mitochondrial DNA
Mitchondrial genetic code differs from nuclear code: UGA, AGA, AUA
tryptophan, STOP not Arginine, methionine not Isoleucine
13 mt. proteins
2 of 46 complex 1 (ND#s), 1 of 11 Complex III, 3of 13 Complex IV, 2 of 16 Complex V (ATPase)
threshold effect varies on…
affected tissue, nuclear genetics of individual, age, environment, nutrition. Every tissue has a different tolerance to mutant mitochondria dependent on the tissues energy needs.
Transgenic mice (added mutant mt. DNA Pol G (gamma). List types of abnormalities that are caused…
- 3-5 fold increase in somatic mtDNA point mutation
- weight loss
- reduced subcutaneous fat
- alopecia (hair loss)
- kyphosis
- osteoporosis
- anemia (20% lower than WT)
- reduced fertility
- heart enlargement
- reduced lifespan
Indications for prenatal Diagnosis (Screening)
- spontaneous abortions
- age >35 yo
- Family HX ID or Developmental Delay
- Fetal Anomalies on Ultrasound
Cystic Fibrosis Clinical Features (4) and mode of inheritance
Autosomal recessive
- Clogged and infected airways
- GI problems: pancreatic duct dysfunction, plugged bile ducts, meconium ileus
- Bilateral absence of the vas deferens (male infertility)
- Salty sweat
Cystic Fibrosis Deletion
Delta F508, deletion of TCT or CTT. 3bp deletion encoding Phenylalanine (hydrophobic a.a)
Duchenne Muscular Dystrophy mode of inheritance and clinical features
X-Linked Recessive
- High levels of CPK in blood (muscle damage)
- Proximal muscle hypertrophy and degeneration, respiratory failure
- Frequent cardiomyopathy and sudden death
Trisomy 21
Epicanthal folds, upslanting palpebrae, small ears, single palmar creases, septal heart defects and moderate intellectual disabilities.
Trisomy 18:
Intrauterine growth retardation, bird-like facies, clenched fists, rocker bottom feet, severe mental intellectual disabilities and poor survival.
Trisomy 13:
Intrauterine growth retardation, holoprosencephaly (prosencephon is the forebrain and in Trisomy 13 it to develop into two hemispheres), seizures, micro-ophthalmia, oro-facial clefts, polydactyly (extra finger and/or toes), severe intellectual disabilities and poor survival.
DiGeorge / velo-cardio-facial syndrome (deletion 22q11.2)
-Contiguous deletion syndrome
Hypocalcemia, long narrow face, long tapered fingers, T-cell defects leading to immunodeficiency, conotruncal heart defects and mild intellectual or learning disabilities.
Turner syndrome (XO)
Short stature, ovarian dysgenesis (infertility), webbed neck, coarctation of the aorta and possible learning or visual spatial disabilities.
Klinefelter syndrome (XXY):
Tall stature, infertility, gynecomastia (breast development in a male), mild learning disabilities and increased risk for behavioral problems.
Triple X (XXX)
Normal physical features, normal fertility (except for possible early menopause), mild learning disabilities with increased risk for psychiatric disorders.
XYY
Tall stature, normal physical appearance, normal fertility, mild learning disabilities and increased risk for behavioral problems.
Signs of Chromosome Abnormalities
Prenatal
Infancy/Childhood
Adulthood
IUGR, MCA, hydrops/edema
MCA,SS,ID,unusual facial features,LD, ADHD
LD, SABs, infertility or stillbirths
Anatomy of cytogenic Variation: Fools Believe Genes are Disposable
facial features, birth defects, growth retardation, development problems
Wolf-Hirschhorn (4p-)- terminal deletion
F: helmet nose, arched eyebrows
B- oro-facial clefts
G- microcephaly
thrombophilia, pulmonary embolisms and increases in blood clotting protein activity
Factor V and Prothrombin gene variants (Both part of common pathway).
1/2 of DVT caused by genetics
Long QT Syndrome (LQT
genes especially those coding K+ and Na+ channels and cardiac arrhythmias
Cardiopathy condition and cardiac muscle protein gene variants? TX?
Arrhytmias condition and genes affected result in? TX?
Hypertrophic cardiomyopathy and MYBPC and MYH7. Genotyping array to identify defective gene, drug and gene therapy, implanted defibrillators, test normal family members, test athletes
Long QT syndrome with the outcome of affecting Na+/K+ pumps. pacemaker and drugs
Early onset familial Alzheimer’s… 5% of disease. Inheritance pattern?
APP (Amyloid precursor protein, Presenilin 1 and
Presenilin 2. Autosomal Dominant
Late onset Alzheimers… 95% of disease
ApoE2 protective and E4 increased risk!!! Polymorphic predisposition alleles. Increased with E4/E4
Obesity and diabetes (Related diseases). Low or high penetrance genes involved?
Leptins, complex regulatory network, many genes. Issues with fat and sugar metabolism. Many low penetrance genes.
Factor V Leiden
Do not inactivate Factor V fast enough thus continue blood clotting cascade
DVT Genetic Risk: Factor V Leiden exhibits what mutation?
G to A (GLN–>Arg)
-inactivation by protein C is rare and heterozygotes are 5X more at risk
DVT Genetic Risk: Prothrombin exhibits what mutation?
G to A in 3’ UTR. Risk is 3X higher in heterozygotes
Dealing with Thrombophilia TX and Screening:
Test for two mutations, asprin, coumadin, heparin, avoid extended immobility and estrogen birth control
Cells needs 4 things
- GFs
- TKR
- intracellular transducers (RAS,MEK, ERK)
- Transcription factors to dictate gene expression
Non-receptor protein kinases for intracellular signal transducers
Transcription factors ex.s
G-proteins, non-receptor protein kinases, serine-threonine protein kinases
myc, fos, jun
p53 as transcription factor elevates (3):
- expression of a CDK (p21) leading to G1 arrest, 2. expression of DNA repair genes, 3. expression of “pro-apoptotic” genes
p53 as cytoplasmic factor (1)
binds to and antagonizes “anti-apoptotic protein” at the mitochondrial surface
Centromere alpha and beta bp #?
where are the alpha and beta satellites found?
171, 68
Are found in other places of the genome but not imprinted to form kinetechores.
SNP - Indel CNV VNTR SSR RFLP
single nucleotide polymorphism (occur at 1% in population and allows to draw genomic distinctions/linkages). Also can be used to genotype a person
-insertion/deletion
copy number variant- large deletion or duplication 50Kb-12Mb. Occurs with unequal crossing over. Chromosomes not lining up properly. Many are DE NOVO!!!; some are inherited
variable number tandem repeat (minisatellites): 10-100 tandem nt repeats. less common compared to SSR esp. for profiling individuals. Unequal crossing over changes up VNTR and SSR.
simple sequence repeat (microsatellites)- best kind of marker for profiling individuals. It is a type of VNTR normally of 1-6 tandem nt repeats
restriction fragment length polymorphism (SNP in a restriction site)
functional polymorphisms
mutation
SNP in genes (Factor II &V), some CNVs.
Missense (CF) and microdeletion (PWS)
Autism possibly linked to ?
CNVs with small 100Kb deletion or 12.5Mb duplication
Cytochrome p450 genes (CYP) encode what enzymes to catalyze what? Why are they important for pharmacogenetics? Ultrametabolizers have mutiple copies of what gene?
–RH2+ O2+ NADPH + H+ –> ROH + H2O + NADP
–Act primarily as hydroxylases and methyl oxidases. Normla fxn is to metabolize xenobiotics (foreign biological molecules) and toxic compounds in liver
- In medicine they are the primary enzymes in drug metabolism. Activates/Eliminates drugs.
-CYP2D6 gene… Alleles include CYP2D6-1 to 17
Drugs to be metabolized by which CYP?: Codeine (opiods) to ? and debrisoquine is a what type of drug and typically used to measure what ?
morphine and antihypertensive drug. collection of opiods is toxic to internal system.
Debrisoquine needs to be modified to be degraded in liver and excreted. Thus the amount of degraded Debrisoquine measures the efficiency of CYP2D6 levels.
Which CYP to metabolize Warfarin?
CYP2C9. Must genotype CYP2C9 genotype before administering Warfarin.
Which CYP to metabolize Plavix (clopidogrel). Clopidogrel converted to what?
CYP2C19. Clopidogrel needs CYP2C19 to convert into active form 2-oxo-clopidogrel. FDA MUST RUN GENETIC TESTING for CYP2C19 before administering Clopidogrel (Plavix). If PM in CYP2C19 then use alternate therapy.
ischemia causes what a decrease of ATP leading to what?
- decrease of Na+ pump–> increase Na+ influx, water, Ca+, efflux of k+ (All lead to swelling of cell)
- detachment of ribosomes–> decrease protein synthesis
- increase anaerobic glycolysis, decrease pH, clumping of nuclear chromatin
contributions to membrane damage (3) which are caused by what (3)?
- phospholipid loss, lipid breakdown product, cytoskeleton products
- decrease oxygen, influx of Ca2+, reactive species produced in reperfused ischemic tissues.
steaosis caused by what
with detachment of ribosomes the lipid protein acceptor is not well made and thus lipids are not successfully exported outside of liver.
thrush breast appearance
caused by fatty change in endocardium
mallory bodies
bleb
- is an inclusion found in the cytoplasm of liver cells. Mallory bodies are damaged intermediate filaments within the hepatocytes.
- a protusion or bulge of the plasma membrane due to dissociation of cytoskeleton from plasma membrane.
CDKI
CDK/Cyclin
CDK>CDKI & CDK
- p21Cip1, p27Kip1
- Cyc D - CDK 4/6
Cyc E - CDK 2
Cyc A - CDK 2 - hyperplasia, hypertrophy
what happens to the fat cells in acute pancreatitis?
acute pancreatitis the enzymes leak out and attack the fat cells
Bcl-2 superfamily proteins
- Anti-apoptotic or Bcl-2 family proteins
- Pro-apoptotic or Bax Family proteins
- Pro-apoptotic “BH3-Only” Family
pyknosis (both)
Karyolysis (only in necrosis)
Karyorrhexis (both)
- condensed chromatin
- nuclear dissolution
- nuclear fragmentation
A type of protease in PCD
Caspase….powerful proteases that target cytoplasmic, cytoskeletal and
nuclear proteins. Caspases fragment chromosomal DNA by activating
nucleases.
CASPase- cysteine active site, and cut @ c’ aspartates of target protein
All PCD pathways converge
at caspase activation
Executor Caspases (Caspase-3, -6, -7): exist as inactive “Pro-Caspases” that are activated by cleavage of the
“Pro” domain by activated Initiator
Caspases (-8 or -9). Dimerize on a specific protein and, cleave of their Pro domain and from a tetrameric Caspase which proteolytically activate Caspase 3 (Cascade)
What is the key even of PCD?
Release of Cyt C from mitochondria through PT pore
Bcl-2 prevents
Bax makes
Bad helps
mt. pore formation
mt. pore
helps to make pore
Puma and Noxa release
Cyt C from mt intermembrane space
Apaf-1 oligomerization to the septameric
apoptosome requires
Cyt C, dATP & ATP.
Procaspase-9 (5-7 molecules) is recruited by
the
Caspase Recruitment Domain (CARD) on
the apoptosome
Procaspase-9 undergoes conformational
change enabling
auto-cleavage, and assembly
of tetrameric Caspase-9.
Caspase 9 cleaves
Pro-Caspase-3 to activate
Caspase-3
Death Ligands bind to and trimerize
Death Receptors, whose intracellular Death Domains
and associated factors (“Disc”) activate Procaspase-8, which then activates Caspase-3
activated Caspase-3
cleaves I-CAD (inhibitor of CAD) into CAD. CAD enters nucleus and cleaves nucleus.
Apoptotic Bodies promote
phagocytosis using
“Find-me” and
“Eat-me” signals
A major surface
determinant for apoptosis is
externalization of
phosphatidylserine which the phagocyte will bind to
Roles of p53 in Apoptosis
As a transcription factor it promotes pro-apoptotic proteins and decrease anti-proapoptotic proteins like Bcl-2. Mostly works intrinsic pathway. Some evidence that in the cytoplasm it binds anti-proapoptotic proteins.
HWE
p2+ 2pq + q2= 1
disease incident for Autosomal Dominant
about 2q, you won’t have homozygous thus genotype has to be 2pq but p is almost 1 thus we get rid of it
In serious dominant and X-linked disease
new mutations represent
SIGNIFICANT PORTIONof disease.
the contribution
of new mutations to recessive disease?
Little affect
Disease incidence
observed disease
CGH detects
CRH detects
CNV
functional SNP that affect mRNA levels
Adenovirus vs retrovirus
CGH vs CRH
Adenovirus:
Advantages
• high efficiency infection
• infects non-growing as well as proliferating cells
• does not integrate into host genome, therefore low
risk of insertional mutagenesis
Disadvantage
• transient expression and immune/ inflammatory
reactions upon reapplication of therapeutic gene
containing virus
Retrovirus
Advantages
• high efficiency infection in bone marrow and other
actively growing cells but infects non-growing cells
poorly
• integrates into the host genome, so can achieve long
term expression
Disadvantage
• insertional mutagenesis is a significant concern
CRH- molecular
stratification of tumors
CGH- mental retardation,
developmental delay, autism and
dysmorphic features
Fragile X- express noFMR-1 mRNA due to CpG hypermethylation in 5’UTR; FX is a loss of function disorder
X-linked dominant. Sherman paradox (50-100CGG 5’UTR) are premature carriers. The premutation expands in women but not in men. Men do not pass on disease to women. Full expression of disease requires >200 CGG repeats.
myotonic dystrophy: CTG repeat in 3’ UTR: gain of function disease due to toxic mRNA
Autsomal Dominant:
Disease due to CTG triplet expansion in the 3’UTR* of DM-1 gene ( DMPK )
•Under 40 CTG is normal. Over 40 CTG repeats have symptoms
•Variable age of onset and severity of neuromuscular degeneration correlates with size of CTG expansion
comparison of FX, DM, HD (autosomal dominant)
FX Loss FMR-1 CGGin 5’UTR 8 –50 50 –100 normal >1000 severe
DM Gain DMPK-1 CTGin 3’UTR 8 –50 50 –100 mild >1000 severe
HD Gain ? CAGin ORF 8 –50 50 –100 severe prenatal lethal
