6/17 - Molecular Diagnostics Flashcards
How do we classify chromosomes?
Discuss the fundamentals of gene expression beginning with the gene and ending with the polypeptide
Germline vs. somatic gene mutations
- GERMLINE -Occur in germ cells => heritable
- SOMATIC -Occur in differentiated cells => not heritable.
Euploid vs. Aneuploid
EUPLOID – Number of chromosomes is a multiple of the haploid genome (23).
ANEUPLOID – Number of chromosomes is NOT a multiple of 23.
Hypo vs hyperdiploid
- Hyperdiploid - Greater than 46
- Hypodiploid – Less than 46
(not a multiple of 23! else it would be in the euploid category like diploid, triploid, etc)
Types of chromosome inversions.
Single chromosome undergoes two breaks and is reconstituted with the segment between the breaks inverted.
Reciprocal translocation
Breakage of nonhomologous chromosomes, with reciprocal exchange of the broken segments.
Double Minutes
Very small accessory chromosomes that contain multiple, amplified copies of a particular DNA segment.
3 types of point mutations
Discuss the NPM1 mutation in Acute Myelogenous Leukemia
Discuss the HER2 mutation
What is PCR?
What is capillary electrophoresis?
What is Lynch syndrome’s mutation and how do we screen for it?
- Lynch syndrome is an autosomal dominant hereditary predisposition to colon cancer and certain other malignancies (e.g. endometrial, gastric) as a result of a germline mismatch repair gene mutation.
- Screening employs microsatellite instability (MSI) testing and/or immunohistochemistry performed on a patient’s colorectal cancer.
Microsatellites?
- Aka short tandem repeats (STR)
- Tandem repeats of a simple DNA sequence, 1-6 base pairs in length, scattered throughout the genome.
