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