Diseases Flashcards
UV Radiation causes…
TpT cyclobutane dimer
also 6-4 photoproduct
skin cancer
Retinoblastoma
pRB gene
tumor supressor gene
trxn problems
Colon Cancer
CpG methylation problem
trxn problems
tumor supressor gene
Adenosine Deaminase Deficiency
ADA defect
SCID (severe combined immunodeficiency)
humoral and innate imm. problems (T & B cells)
less DNA synthesis
Beta Thalassemia - trxn problems…
Unable to synth. Beta-Hemoglobin
mutation in TATA box
trxn problem - initiation
clinically severe
Xeroderma Pigmentosum
XBP (part of TF II H) = helicase activity in Poll II
Unable to repair UV damage
Autosomal Recessive
DNA repair problem
Marfan Syndrome
splicing defect
fibrolin gene
Tall, protruding chest, aortic weakness
Beta-Thalassemia - control element
mutation in DNA control element
beta-globin promoter
less beta-globin mRNA produced in erythroid cells (anemia)
generally clinically mild
gamma-delta-geta Thalassemia
mutation in DNA control element
deletion of locus control region in Beta-globin gene cluster
LCR responsible for trxn of all genes in the cluster
Hemophelia B Leyden
mutation in DNA control element
Factor IX deficiency
X-linked recessive
Clotting problems till puberty
Fragile X Syndrome
mutation in DNA control elements
mental retardation, facial defects, postpubertal macroorchidism
CGG repeat in 5’ region of FMR1 gene facilitates methylation of C in CpG islands —> trxn’l inactivation of FMR1 gene
normal males = 6-50 repeats. affected males = >200 rpeats —> incresed trxn of FMR1
Different Beta Thalassemias
Splicing defect - TATA box binding, single bp mutation = severe beta globin deficiency
Control Element defect = reduced beta globin production = less severe
IgM can have two different versions. What are they and what process differentiates them?
Different poly A tail site choice will produce either a membrane IgM or a secreted (serum) IgM
Why is splicing of CD44 significant?
abnormal splicing of CD44 contributes to tumor metastisis
is a predictor of tumor metastisis (diagonistic and prognostic)
Altered poly A in cancer cells?
cleave upstream from normal site. shortened 3’UTR, extended poly A tail