Cytogenetics & Copy Number Variation Flashcards
Microdeletion/microduplication syndromes are those that involve deletion or duplication of ____ of DNA, and cannot be visualized by ____
<10 Mb
G-banding
Deletion 22q11.2:
DiGeorge/Velcro-cardio-facial syndrome
Deletion 15q11.2:
Prader Willi Syndrome/ angelman syndrome
Most deletions in AS and PWS and those of 22q11.2 are exactly the same size due to the fact that genomic regions that immediately flank the deleted regions are composed of ____ ___ ____
Low copy repeats (LCR)
The deletions is generated by_____ _____ ____ between these low copy repeats (LCR)
Non-Allelic homogolous recombination
Such low copy repeats also flank the breakpoints of other ____ _____ ____ (Williams, 22q11.2)
Recurrent microdeletion syndromes
Low copy repeats result from ____ _____ of the genome. Low copy repeats are Typically 10-500 kb in size. They Typically share ______ identity
Segmental duplication
95 to 99% identity
The genomic architecture of certain chromosomal regions (with intervening ___ ___ ___) predispose them to NAHR and the generation of duplications and deletions
Low Copy Repeats (LCR)
Diagram of nonallelic homologous recombination
22q11.2 deletion syndrome has high ____ ____. Most common symptoms include _____ ____, ____ ____, and ____
Variable expressivity
Cardiac anomalies
Immune deficiency
Hypocalcemia
_____ to ____ of DNA fragment is a way to visualize deletions and duplications. You take a patient and control DNA, mix them together, place into a ___ ___. Green shows a ____, red shows a ____
Hybridization
Array
Laser scanner
Duplication
Deletion
-1 equals _____ of one copy
0 equals ____ ___ or gain
Loss
No loss
Two different clinical disorders are caused by the same ___ ___ ____ on chromosome 15: ___ ___ syndrome and ____ syndrome
5 Mb microdeletion
Prader Willi
Angelman
Clinical findings in Prader Willi syndrome:
Infant:
Childhood/adulthood:
Hypotonia; failure to thrive, Feeding/sucking difficulties, Characteristic facial features, developmental delays
Progressive hyperphagia (increased appetite) and fat deposition, sleep apnea, behavioral issues, anxiety, compulsive skin picking, high pain tolerance, and cognitive disability
Clinical symptoms of Angelman syndrome:
Microcephaly, protruding jaw, developmental delays, ataxia gait, severe language delay, seizures, happy demeanor, inappropriate bursts of laughter, high pain tolerance, difficult sleeping, hyperactivity, and scoliosis
In 70% of individuals with PWS or AS, there is a __ ___ ___ in 15q.11.2. The deletions are identical but the clinical syndrome are different due to ____
5 Mb deletion
Imprinting
Imprinting is differential ___ of a gene depending upon the parent of origin. PWS genes are expressed exclusively from the _____ derived chromosome 15. AS genes are expressed exclusively on the ___ derived chromosome 15
Expression
Paternally
Maternally
Two tests for PWS and AS:
1. ____ testing: can tell if the genes are expressed or not
2. _____: can tell you if the genes are present or deleted
Methylation
Microarray
Blue: ____ expressed genes, lack of expression leads to Prader Willi
Red: _____ expressed genes, lack of expression leads to angelman syndrome. _____ is the single gene responsible for AS. There is no single gene responsible for PWS
Paternally
Maternally
UBE3A
This pregnancy underwent uni-parental disomy
A _____ is a first responder to the site of infection. It is a _____ and represents 40 to 60% of all leukocytes. It releases toxins that kill or inhibit bacteria. It recruits other ____ cells
Neutrophil
Phagocyte
Immune
A _____ is responsible for defense against parasites. It releases _____ that cause inflammation and may be responsible me for ____ reactions. It circulates in the ____ ___ into tissues
Basophil
Histamines
Allergies
Blood vessels
An ______ releases ____ that kill bacteria and parasites, but also causes tissue damage. They circulate in the ____ and migrate to tissue
Eosinophil
Toxins
Blood
Neutrophils, basophils, and eosinophils are all _____.
Granulocytes
