Cytogenetics and Nomenclature Flashcards
Learn about chromosomes, abnormalities, & translocations
Function of satellite stalks?
- contain nucleolar organizing regions (NORs)
- site of rRNA genes & production
-somy vs. -ploidy meanings?
- somy indicates one chromosome
- pleudy indicates a whole set of chromosmes
Routine chromosome analysis covers what band level?
400-550 bands
High resolution chromosome analysis covers what band level?
550-850 bands
What is the purpose of FISH (fluorescence in situ hybridization)?
Helps determine # & location of spec DNA seq’s (probes)
What syndrome is asoc w/ interstitial deletion of 17p11.2?
Smith-Magenis syndrome
Steps of FISH? (5)
- Create DNA probe
- DNA probe labeled w/ fluorescent dye
- DNA denatured & sep’d
- Probe hybridized w/ pt chromosomes
- Fluorescent probe illuminates chromosome region of interest
3 categories of FISH probes?
- unique sequence probes (aka gene specific)
- repeat seq probes
- chromosome painting probes
What are 2 major types of repeat seq probes? (Hint: assoc w/ well-known chromosome repeats)
- centromeric probes bind to centromeric repeats
2. telomaric probes bind TTAGGG
5 clinical application of FISH?
- chromosome microdeletion syndromes
- structural chromosome abnormalities
- characterize marker chromosomes
- prenatal aneuploidy screen
- oncogene amplification
What syndrome is caused by 46,XX,del(4)(p15.3)?
Wolf-Hirschhorn syndrome (Greek helmet syndrome)
What is 47,XXY?
Klinefelter syndrome
Major symptoms of Klinefelter syndrome? (6)
- tall than avg
- reduced facial/body hair
- breast dvp’ment (gynaecomastia)
- osteoporosis
- feminine fat dist
- testicular atrophy
What is 46,XY,del(5)(p14.2)?
Cri-du-Chat syndrome
Define Robertsonian translocations
- spec class of translocations where 2 acrocentric chromosomes (13,14,15,21,22) join @ centromere
