Adkison Quizlet- MOD Neuroscience Genetics Flashcards
Lisch nodules
Neurofibromatosis
CGG repeat
Fragile X
CAG repeat
Huntington disease
cafe-au-lait spots, plexiform neurofibromas
Neurofibromatosis 1
cafe-au-lait spots, vestibular schwannomas
Neurofibromatosis 2
mitochondrial disorder with epileptic seizures and degeneration of brain; ragged red fibers
MERRF
Formerly called von Recklinghausen
NF1 or peripheral neurofibromatosis was called this
Major clinical features of neurofibromatosis 1
Major features are: cafe-au-lait spots, freckling, peripheral neurofibromas, lisch nodules
Cafe-au-lait diagnostic criteria in NF1
6 or more cafe-au-lait spots
Variable expressivity means
The phenotypic features can vary between individuals with the same genotype.
Site of peripheral neurofibroma development
They develop on peripheral nerves.
Most common cause of morbidity in NF1
Plexiform neurofibroma causes this in NF1
NF1 gene
neurofibromin gene
Alternative splicing produces these
different isoform; different proteins from same gene
Function of neurofibromin
tumor suppressor; negative regulator of RAS is the function of this protein
Another name for NF2
bilateral acoustic neurofibromatosis
Nerve often involved in NF2
CN 8
Adult onset NF
NF2
Child onset NF
NF1
Most common form of NF
NF1
Frequent early symptom of NF2
hearing loss with tinnitus or vertigo is an early symptom
NF2 gene
merlin is the gene
NF2 protein function
function is tumor suppressor binding to membrane bound proteins/receptors
NF affecting only one region of body
This is called segmented NF1 or NF2.
Purpose of purine/pyrimidine salvage pathways
recover nucleotides rather than creating them de novo
Substrates for purine/pyrimidine salvage pathways
DNA/RNA are the substrates for these
HPRT or HGPRT
hypoxanthine/guanine phosphoribosyl transferase is abbreviated this way
Products for HPRT/HGPRT
IMP and GMP are the products of these enzyme
Substrates for HPRT/HGPRT
Hyoxanthine and guanine are the substrates of these enzymes
Mechanism of inheritance for Lesch-Nyhan disease
X-linked inheritance
Self-mutilation is seen in severe cases
Lesch-Nyhan disease has this severe presentation
Mutation in Lesch-Nyhan disease
HPRT mutation
HPRT mutation causes
Lesch-Nyhan disease cause
Joint disease associated with Lesch Nyhan
Gout
Color of urate crystals
orange is the color
Triplet expanded in fragile X
CGG is expanded
Fragile X expansion occurs in what parent
Expansion occurs in the mother
Mechanism of triplet expansion
DNA slippage is the mechanism
Fragile X etiology
Promoter down-regulation is the disease mechansim
Triplet expanded in Huntington disease
CAG is expanded
Huntington disease expansion occurs in what parent
Expansion occurs in the father
Major features of fragile X in males
long face, high arched palate, large ears, macroorchidism
Features fragile X in females
tremors/ataxia, premature ovarian failure, mild mental retardation
Features of Huntington disease
progressive neuronal death, chorea, dementia
Anticipation in triplet disease means
earlier age of onset with greater numbers of repeats
Disease range of triplets in fragile X
> 200 repeats
Disease range of triplets in Huntington disease
> 38 repeats
Normal cell location of HTT
cytoplasm is the location
Cell location of mutant HTT
nucleus is the location
Brain localization of HTT
located in cerebellum, cortex, striatum
Atrophies in Huntington disease
caudate nucleus, putamen, nucleus accumbens
Fundamental unit of sphingolipids
ceramide is fundamental unit
Most complex group of sphingoglycolipids
gangliosides are the most complex
GM2 gangliosidosis examples
Tay-Sachs and Sandhoff
Sphingolipidosis examples
Krabbe, Fabry, Gaucher, Niemann-Pick
X-linked sphinolipidosis
Fabry disease is X-linked
Site of ganglioside and sphingolipid accumulation
Accumulate in cell
Site of mucopolysaccharide accumulation
Accumulate outside of cell
Tay-Sachs disease mutation
Hexosaminidase A mutation
Sandhoff disease mutation
Hexosaminidase B mutation
Site of GM2 accumulation in gangliosidoses
CNS/ANS, retina
Eye finding in lysosomal storage diseases
cherry red spot of the macula
Defect in MPS diseases
heparan sulfate and dematan sulfate degradation pathways
Most severe MPS
Hurler syndrome
X-linked MPS
Hunter syndrome
Mild MPS (also MPS III)
Sanfilippo syndrome
Mild form Hurler syndrome
Scheie syndrome
Hurler syndrome mutation
alpha-iduronidase
Accumulated product in MPS I
heparan sulfate and dermatan sulfate accumulate
Accumulated product in MPS III
heparan sulfate
Accumulated product in MPS II
heparan sulfate and dermatan sulfate accumulate
Example of a compound heterozygote
Hurler-Scheie syndrome
Mutation in Hunter syndrome
Iduronate sulfatase is mutated
Two examples with recombinant enzyme treatments
MPS I (alpha iduronidase) and Fabry disease (alpha galactosidase) are examples
Major clinical sign in Alzheimer disease
progressive dementia is clinical sign
Major findings in Alzheimer neuropathology
beta-amyloid plaques and neurofibrillary tangles
Neuroimaging of Alzheimer brains shows these
cortical thinning, loss of gray matter
Greatest causes of Alzheimer disease
About 75% of cases have unknown etiology
Types of early onset AD
AD 1, 3, 4
Mutation in AD 1
Amyloid beta precursor protein (APP) mutation
Mutation in AD 3
Presenilin 1
Mutation in AD 4
Presenilin 2
Components of gamma secretase
PS 1, PS 2, nicatrin, APH1
Secretase forming only non-toxic products
Alpha secretase forms this product
Beta secretase products
AB40 and AB42
Toxic product of beta secretase
AB42
Gene involved in late onset AD
Apolipoprotein E (APOE) is the gene
Site of brain synthesis of APOE
microglia/astrocytes
Function of APOE in brain
transports cholesterol to neurons
Why do neurons need cholesterol
membranes, synaptic integrity, normal neuron function
3 things APOE regulate in brain
AB level, AB deposition, AB clearance
APOE allele associated with low AD incidence
APOE2
APOE allele associated with late onset AD
APOE4
Cell structure associated with tau proteins
microtubules
Function of tau proteins
regulates microtubule assembly and stability
Normal phosphorylation state of tau
Low phosphorylation state in normal conditions
Phosphorylation state of tau aggregates
hyperphosphorylation is in tau aggregates
Number of tau isoforms
6 isoforms
Different functions of isoforms
plasticity and stability
Two major sources of free radicals
mitochondria and NADPH oxidase
Function of microglia
clear and degrade amyloid beta proteins
Pathway generating superoxide in cells
oxidative phosphorylation creating excess electrons
Ox-Phos complex involved in brain superoxide formation
Complex I in the brain
Superoxide reacts with nitrous oxide to form
peroxynitrates are formed from these
Secreted by microglia
IL, TNFa, TGFb
Dysfunctional microglia in AD result in this
decreased APOE receptors, decreased cholesterol transport
Increased TNFa and IL-6 cause this
sickness behavior is caused by these
symptoms of sickness behavior
anxiety, depression, apathy
system inflammation characteristics
increased C-reactive protein, TNFa, IL-6
cafe-au-lait spots in NF2
less than 6 typically
skeletal abnormality associated with MPS
oval-shaped vertebrae had hook-shaped spious processes
deformities associated with MPS
gibbus deformity and lumbar kyphosis
function of FMRP
transports specific mRNAs to cytoplasm for translation (prevents mental retardation)
HTT stimulates production of this
brain derived neurotrophic factor (BDNF)
Femur deformity associated with Gaucher disease
Erlenmyer flask deformity
Mutated enzyme in Gaucher disease
glucocerebrosidase is mutated
Mutated enzyme in Krabbe disease
galactocerebrosidase is mutated
Characterized by pain in extremities, may be intermittent
Fabry disease
Two abnormal proteins associated with early onset AD
APP and gamma-secretase (composed of presenilins and 2 other proteins)
Two subunits of sphingolipids
sphingosine and a fatty acid
Site of MPS (GAG) accumulation
extracellular spaces of connective tissues