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50 Cards in this Set
- Front
- Back
Bloom's Syndrome
|
- AR
- DNA helicase deficiency - leukemia & other malignancies |
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Werner's Syndrome
|
- AR
- DNA helicase deficiency - dwarfism, cataracts, premature aging |
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Li-Fraumeni Syndrome
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- AR
- mutated p53 - tumor development at multiple sites |
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Xeroderma Pigmentosum
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- AR
- defective DNA repair - malignant skin tumors that metastasize |
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Sickle-Cell Anemia
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- AR
- point mutation to HbS has valine substituted for glutamate at amino position #6 - detected by Southern Blot - hemoglobin can't bind oxygen - poor growth, pain, poor immune response - RFLP used to distinguish genotypes |
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Thalassemia
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- AR
- defective synthesis of one or more Hb chains (α or β) - anemia - 25% of mutations are in sequences for correct splicing |
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Huntington's Disease/Chorea
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- AD
- trinucleotide repeat of CAG (>35 copies) - more repeats = earlier onset - leads to huntingtin protein accumulation in the nucleus - involuntary movements (chorea), memory loss, dementia - Southern Blot detectable |
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Progeria
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- de novo mutation
- defect in nuclear lamins (laminopathy) - limited growth, advanced aging, alopecia |
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Restrictive Dermopathy
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- AR
- neonatal laminopathy - tight skin, secondary joint changes, spare or absent eyelashes, abnormal facies |
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Hereditary Spherocytosis
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- AD
- spectrin deficiency, improper membrane-cytoskeletal interaction - splenomegaly, accumulating RBCs in spleen w/ macrophages, anemia from destroyed RBCs - spectrin, actin, ankyrin, bands 4.1 and 4.2 in RBC bilayer |
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HIV/AIDS
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- HIV gp120 binds CD4+ T-cells, causing rapid fusion of viral coat w/ host membrane
- viral genome replicates using reverse transcriptase and integrase to insert DNA into host chromosome - viral glycoprotein inserted on infected cell membrane |
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Coccidiosis
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- protozoan infection Coccidia
- have highly specific recognition proteins that bind to glycoproteins on host - can determine what species based on location of GI infection |
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Walking Pneumonia
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- Mycoplasma infection on respiratory epithelium
- attach to cilia & extract cholesterol from plasma membrane of cells - low cholesterol increases membrane fluidity, cilia can't beat |
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Fabry's Disease
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- lysosomal storage disease, XLR
- α-galactosidase A deficiency, ceramide build-up - anhydrosis (lack of sweating), fatigue, angiokeratoma (small skin lesions), kidney failure - enzyme replacement therapy |
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Gaucher's Disease
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- most common lysosomal storage disease
- defective β-glucosidase, glucocerebroside accumulation - enzyme replacement therapy |
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Cystic Fibrosis
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- AR
- mutation in CFTR gene (delta F508), defective chloride transporter cannot move Cl- out of cell, causes Na+ to come into cell, water follows - results in viscous mucus - neutrophils recruited to kill pathogens and release enzymes that do further damage - bronchiectasis, pulmonary hypertension, eventual heart failure, pancreatitis and malabsorption - allele specific oligo testing detects 25 most common mutations in CFTR gene |
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Familial Hypercholesterolemia (FH)
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- AD, example of dosage effect (homozygous more severe than heterozygous)
- defective receptor-mediated endocytic process - defect in LDL receptor: fails to bind LDL properly, fails to cluster in coated pits, or fails to anchor in membrane |
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Tangier Disease
|
- AR
- defective ABC1 transporter for cholesterol export from cells - reduced HDL in plasma - connection to CHD |
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Legionnaire's Disease
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- infection by L. pneumophila
- exploitation of phagocytosis - pathogen of respiratory tract; neutralizes acidification of endosome and prevents phagolysosome formation |
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Leishmania
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- protozoan parasite
- internalized but not killed in phagolysososme |
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Leprosy
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- caused by mycobacteria
- internalized but not killed in lysosome due to waxy coating - not destroyed by acidity |
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I-cell Disease
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- lysosomal storage disease
- missing N-acetylglucosamine phosphotransferase, which phosphorylates mannose residues - enzymes lack mannose 6-phosphate, so can't be targeted to lysosomes to break down polymers |
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Zellweger Syndrome
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- peroxisomal disease that affects kidneys, liver, and brain
- defective peroxisome targeting due to mutated SKL signal sequence - lack of muscle tone, poor vision, glaucoma - can't β-oxidize very long chain fatty acids |
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Neonatal Adrenoleukodystrophy (NALD)
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- peroxisome targeting disease
- defect in transport protein that carries very long chain fatty acids to peroxisomes - accumulation of fatty acids causes myelin degeneration |
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Kartagener's (Immotile Cilia) Syndrome
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- AR
- dyneins are lacking or abnormal - axoneme present, but no cilia/flagella movement (dyneins power axonemes) - respiratory infections, infertility |
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Tau-opathy
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- neurodegenerative disease
- Tau is a microtubule binding protein (MAP) - mutant Tau from altered splicing doesn't bind MT properly |
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Listeriosis
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- infection of gram (+) L. monocytogenes
- once inside an intestinal epithelial cell, it hijacks the actin system to propel itself into neighboring cells (evades immune system) - food poisoning, meningitis, abortion - smallpox has similar mechanism |
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Epidermal Blistering
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- defect in keratins (IFs)
- failure of hemidesmosomes to anchor epithelial cells to basal lamina causes separation, fluid entry |
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Neurofibromatosis I
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- AD
- mutation on chromosome 17 for neurofibromin - cafe au lait spots, neurofibromas, CNS tumors, scoliosis, macrocephaly |
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Achondroplasia
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- AD
- gain of function mutation (ligand-independent activation of FGFR3), chromosome 4 - advanced maternal age - inhibited bone growth, short extremities, large head, trident hands, saddle nose |
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Tay-Sachs Disease
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- lysosomal storage disease
- AR - absence of hexosaminidase A leads to build up of GM2 ganglioside in CNS - mental retardation, blindness, death |
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Hemophilia
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- XLR, affects mostly men
- deficient in factor VIII for clotting blood - risk for fatal bleeding |
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Duchenne Muscular Dystrophy
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- XLR, affects mostly men
- absence of protein dystrophin leads to muscle weakness and wasting - creatine kinase in 2/3 female carries ↑ |
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Incontinentia Pigmenti
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- XLD, lethal in males
- females have hyperpigmented, marbled appearance on trunk and extremities |
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Osteogenesis Imperfecta II
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- dominant-negative mutation
- new germline mutation in procollagen - point mutation causes a glycine --> cysteine substitution - defective assembly of fibers leads to abnormal type I collagen and brittle bones |
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Phenylketonuria
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- AR, loss-of-function mutation
- deficiency in phenylalanine hydroxylase - can't convert Phe to Tyr - Phe accumulates in brain, leads to mental retardation, seizures |
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Trisomy 21 (Down Syndrome)
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- strong link with advanced maternal age
- flat facial profile, upward-slanting eyes, small ears, nose, and mouth, congenital heart disease - 50% have single palmar crease, 50% have clinodactyly (bent 5th finger) - short stature, microcephaly, moderate mental retardation - life expectancy 50 years |
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Trisomy 18 (Edwards Syndrome)
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- strong link with advanced maternal age
- microcephaly, micrognathia (undersized jaw), small mouth, congenital heart disease, overlapping fingers, low-set ears, prominent occiput, rocker bottom feet - most (95%) die within one year of life |
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Trisomy 13 (Patau Syndrome)
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- strong link with advanced maternal age
- oral-facial clefts, microphthalmia, microcephaly, cardiac anomalies, polydactyly, CNS malformations - most (95%) die within 6 months of life - 80% are straight trisomy, translocations involved in others |
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Cri-du-Chat Syndrome
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- deletion of terminal part of chromosome 5 (85% de novo mutation)
- cat-like cry, mental retardation, failure to thrive - detected w/ FISH |
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Turner Syndrome
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- 45, X (mosaicism possible)
- 1/3 babies detected at birth w/ webbed neck, puffy hands & feet, low-set ears, and congenital heart disease - 1/3 detected as children due to short stature - 1/3 detected when puberty delayed |
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Klinefelter Syndrome
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- 47, XXY
- most often from mom w/ advanced age - relatively tall with long legs, small testes, enlarged mammary glands, gynecomastia |
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Fragile X Syndrome
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- XLD
- unstable trinucleotide repeat CGG at Xq27 (>200 repeats) - derived from premutation or maternally derived full mutation - dementia, hypotonia |
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Myotonic Dystrophy
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- AD w/ anticipation
- unstable trinucleotide repeat GCT (>50 repeats) - wasting of muscles, cardiac arrhythmias, cataracts, temporal balding |
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Leber's Hereditary Optic Neuropathy
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- homoplasmic point mutation in mtDNA
- classical maternal inheritance - sudden bilateral, irreversible loss of vision due to optic nerve death |
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MELAS
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- heteroplasmic point mutation
- classical maternal inheritance with high variability of expression - stroke-like episodes, migraines, seizures, dementia, diabetes |
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Pearson Syndrome
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- de novo deletion mutation of 1/3 mtDNA
- anemia, pancreatic fibrosis, death before age 3 usually |
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Creutzfeld-Jakob Disease
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- a.k.a. Mad Cow Disease
- single AA mutation switches α-helical form of protein to β-aggregated form - inherited missense mutation or ingest "bad protein" that influences other proteins - age 29 average onset --> depression, dementia, other psych symptoms |
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Scurvy
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- ascorbic acid (vitC) deficiency
- necessary cofactor for prolyl hydroxylase activity - deficiency yields collagen fibers with low hydroxyproline content (low melting point) - fragile tissues and organs - bleeding gums, pinpoint hemorrhages, fragile blood vessels |
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Ehlers-Danlos Syndrome
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- defective collagen synthesis due to lack of an enzyme
- hyperelastic joints and skin hyperextension |