Difference between revisions of "Cytogenetics Review Questions"
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{{hidden|What is imprinting?|Normally we inherit one copy of each gene from each parent, some genes are only expressed when they are inherited paternally, some only when maternally, this differential expression based on inheritance is called imprinting, and changes generation to generation.}} | {{hidden|What is imprinting?|Normally we inherit one copy of each gene from each parent, some genes are only expressed when they are inherited paternally, some only when maternally, this differential expression based on inheritance is called imprinting, and changes generation to generation.}} | ||
{{hidden|Which chromosomes are known to have imprinted genes?|Chromosomes 6,7,11,14,and 15.}} | {{hidden|Which chromosomes are known to have imprinted genes?|Chromosomes 6,7,11,14,and 15.}} | ||
{{hidden|Describe Prader-Willi Syndrome.| | {{hidden|Describe Prader-Willi Syndrome.|Features: hypotonia, obesity, developmental delay, hypogonadism, short stature, 70%: del(15q11-13), 25% uniparental disomy, 2%:other, diagnoses by FISH for microdeletion, or DNA methylation; due to absence of paternally derived PWS/AS gene }} | ||
{{hidden|Briefly describe Williams Syndrome.|Deletion of one elastin allele (7q11.23 = 96% of cases), multi-system d/o characterized by: Growth & developmental delay, characteristic facies & personality, supra valvular stenosis, idiopathic infantile hypercalcemia (connective tissue / vascular)}} | {{hidden|Briefly describe Williams Syndrome.|Deletion of one elastin allele (7q11.23 = 96% of cases), multi-system d/o characterized by: Growth & developmental delay, characteristic facies & personality, supra valvular stenosis, idiopathic infantile hypercalcemia (connective tissue / vascular)}} | ||
{{hidden|Describe DeGeorge Syndrome.|95% 22q11.2 deletion, 5% FISH negative; AD inherit; 1) Conotruncal heart defects, 2)uropathy, 3)polyhydramnios,4)increased nuchal translucency, 5) IUGR, 6)thymic hypoplasia, 7) characteristic facies, 8) hypoparathyroidism, 9)MR/DD}} | |||
{{hidden|What is SKY?|A chromosomal analysis technique that has the ability to paint each pair of chromosomes and the sex chromosomes a different flourescing colour.}} | |||
{{hidden|What kinds of chromosomal transformations is SKY used for?|1) translocations, 2) insertions, 3)marker chromosome identification, 4) cancer tumour genetics}} | |||
{{hidden|What are three limitations of SKY?|1) cannot detect del,dup,inv, 2) interpretation difficult if colours too similar}} | |||
{{hidden|Explain the basic principle of Comparative Genomic Hybridization.|References genomes and the index genome are mixed, if the index genome substantially differs from the reference genome then there will be a neg signal loss or gain for that probe's flourescence, this can be used to determine if there is one allele in the index case that is missing or in excess compared to the reference genome.}} | |||
{{hidden|How do CGH arrays work?|CGH arrays allow hundreds-thousands of probes to be used to compare the index and the reference genome, giving a complete chromosomal analysis that depends on the resolution of the probe.}} | |||
==Unit 4== | |||
==Miscellaneous== | |||
{{hidden|What is Allerdice or Sandy Point Syndrome?|It is a chromosomal disorder discovered in Sandy Point, NL by Dr. Penny Allderdice, inv(3)(p25q21) characterized by affected offspring with multiple congenital anomalies with surviving children exhibiting severe growth and developmental delays.}} | |||
{{hidden|What is the most common robertsonian translocation?|Translocation between the long arms of 13 and 14.}} | |||
{{hidden|What is the most common non-robertsonian translocation?|t(11;22)(q23;q11)}} | |||
{{hidden|What is a marker chromosome?|A structurally abnormal chromosome in which no part can be identified cytogenetically.}} | |||
{{hidden|What is the most common chromosomal abnormality in humans?|Aneuploidy - about 5% of pregnancies.}} | |||
{{hidden|What is the most common cause of triploidy?|Dispermy in 60%}} | |||
{{hidden|What is the recurrence risk for parents of Down's syndrome child with a "free chromosome"?|1%}} | |||
{{hidden|List 5 features of Trisomy 8.|}} | |||
{{hidden|List 5 features of Trisomy 9.|}} | |||
{{hidden|List 5 features of Trisomy 13.|}} | |||
{{hidden|List 5 features of Trisomy 14.|}} | |||
{{hidden|List 5 features of Trisomy 18.|}} | |||
{{hidden|List 5 features of Trisomy 21.|}} | |||
{{hidden|What is the most common outcome of a pregnancy when the parent has a balanced translocation?|Misscarriage}} | |||
==Peripheral Blood Culture and Harvest== | |||
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Revision as of 18:13, 22 May 2015
Unit 1
Expand List the three broad categories of clinical indications for chromosomal analysis.
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Expand List 5 prenatal indications for cytogenetics analysis.
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Expand Which family members should have chromosomal analysis?
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Expand What are the indications for chromosomal analysis of products of conception?
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Expand Compare amniocentesis and chorionic villus sampling with regards to gestational age, complication rate, turn around time, and false results
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Expand What are the clinical indications for tissue sampling instead of blood for cytogenetic analysis?
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Expand List 8 standard techniques for cytogenetics analysis.
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Expand List 5 Molecular cytogenetics techniques.
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Expand What is g-banding?
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Expand Outline the general procedure for cytogenetics study.
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Expand Broadly what at the three main morphological groups of chromosomes?
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Expand What are the 4 minimum items included in a standard banding nomenclature?
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Expand What are the clinical indications for an individual to have chromosomal analysis?
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Expand What is q-banding?
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Expand What is R-banding?
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Expand What is C-banding?
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Expand What is NOR?
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Expand List the metacentric chromosomes.
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Expand List the submetacentric chromosomes.
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Expand List the acrocentric chromosomes.
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Expand What is Bloom syndrome?
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Expand What is SCE (Sister chromatid exchange?
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Expand What is DAPI staining?
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Expand Explain how chromosomal breakage studies are used to diagnose Fanconi's anemia.
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Unit 2
Expand Describe the 4 steps of mitosis.
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Expand List the 8 steps of meiosis.
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Expand What is the main difference between constitutional and acquired chromosome anomalies.
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Expand What at the three main categories of patient features associated with unbalanced constitutional chromosomal anomalies?]1) dysmophy, 2) Visceral malformations, 3) developmental/psychomotor delay.
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Expand What is meant by a homogeneous chromosomal anomaly?
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Expand What is meant by a mosaic chromosomal anomaly?
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Expand What are chromosomal polymorphisms?
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Expand List 3 known chromosomal polymorphisms, according to ISCN 2013.
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Expand Classify numerical abnormalities of chromosomes.
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Expand What are the four main types of abnormalities in chromosome structure?
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Expand What is the key difference between a balanced and an unbalanced chromosomal rearrangement?
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Expand List three types of balanced chromosomal rearrangements.
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Expand List three unbalanced numerical chromosomal rearrangements.
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Expand List 5 structural unbalanced chromosomal rearrangements.
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Expand What is the karyotype for a female infant with cri-du-chat?
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Unit 3
Expand What is FISH?
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Expand When is interphase FISH more helpful than metaphase?
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Expand What is the approximate resolution of cytogenetic FISH?
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Expand What are the three types of FISH probes?
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Expand List 7 applications of FISH technology?
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Expand List 5 microdeletion syndromes.
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Expand Briefly describe Cri-du Chat Syndrome
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Expand Describe 3 mechanisms by which uniparental disomy occurs.
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Expand What is imprinting?
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Expand Which chromosomes are known to have imprinted genes?
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Expand Describe Prader-Willi Syndrome.
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Expand Briefly describe Williams Syndrome.
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Expand Describe DeGeorge Syndrome.
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Expand What is SKY?
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Expand What kinds of chromosomal transformations is SKY used for?
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Expand What are three limitations of SKY?
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Expand Explain the basic principle of Comparative Genomic Hybridization.
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Expand How do CGH arrays work?
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Unit 4
Miscellaneous
Expand What is Allerdice or Sandy Point Syndrome?
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Expand What is the most common robertsonian translocation?
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Expand What is the most common non-robertsonian translocation?
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Expand What is a marker chromosome?
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Expand What is the most common chromosomal abnormality in humans?
|
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Expand What is the most common cause of triploidy?
|
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Expand What is the recurrence risk for parents of Down's syndrome child with a "free chromosome"?
|
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Expand List 5 features of Trisomy 8.
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Expand List 5 features of Trisomy 9.
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Expand List 5 features of Trisomy 13.
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Expand List 5 features of Trisomy 14.
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Expand List 5 features of Trisomy 18.
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Expand List 5 features of Trisomy 21.
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Expand What is the most common outcome of a pregnancy when the parent has a balanced translocation?
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Peripheral Blood Culture and Harvest
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