24: Molecular Pathology Flashcards
molecular diagnostic techniques can be used to … (4)
- detection of inherited or acquired mutations
- accurate diagnosis and classification of tumors
- detection of infectious agents
- tissue typing, paternity testing and forensic medicine
what analysis can be used to look for aneuploidy, sex chromosomal abnormality, fragile X, and translocations
cytogenetic analysis
what are 2 advantages of molecular analysis v. cytogenetic analysis
- very sensitive and so sample size can be small
- not dependent of analysis of the gene product so almost any cell will work
the loss or gain of an entire chromosome
genome mutation
what analysis can be used for genome mutations
cytogenetic or molecular analysis
rearrangement of genetic material
chromosme mutation
what analysis can be used for chromosme mutations
cytogenetic or molecular analysis
the complete deletion of a gene or as little as a single point mutation
gene mutation
what analysis can be used for gene mutations
only molecular techniques
mutations at certain positions in the introns can cause errors in …
splicing
mutation in the promoter or enhancers of gnees can cause a decrease in..
expression
mutations in the poly A tail at the 3’ end of the gene can lead to …
unstable mRNA
B thallassemia
different mutations causing the same disease
- splice site
- poly A tail
- promoter/enhancer
mutations in the DNA by comparison with a known DNA sequence
direct detection
through linkage of the disease gene with a marker that is nearby
indirect detection
if a mutation alters or destroys a restriction endonuclease site on the DNA then it can be detected by: (3)
- amplifying the region of interest with PCR
- digesting the PCR products with the appropriate restriction enzyme
- separating the digestion products by electrophoresis
linkage of the disease gene with a marker that is nearby
indirect detection of mutations
via site and length polymorphisms
Does NOT require the gene sequence to be known but DOES require that the polymorphism used for detection e sufficiently close to the mutated gene so that the marker and the mutation are inherited together
indirect detection or linkage analysis
study of heritable chemical modifications of DNA or chromatin that does not change the DNA sequence
epigenetics
methylation of DNA and methylation or acetylation of histones
epigenetic alterations
increased methylation –>
decreased expression of a gene
histone acetylation –>
decreased gene expression
