Lecture 14 - Clinical Cytogenetic Diagnoses

Question 1

______ is the term that refers to having an incomplete set of chromosomes.

Answer 1

Aneuploid

Question 2

____ is the term for having the correct complement of chromosomes.

Answer 2

Euploid

Question 3

The vast majority of ______ associated with disease are intronic or intergenic.

Answer 3

SNPs

Question 4

The two arms of the chromosome are separated by the ________.

Answer 4

centromere - the point at which the chromosome is attached to the spindle during cell division

Question 5

If constriction by the centromere is near one end of the chromosomes, the chromosomes are classified as:

Answer 5

acrocentric

Question 6

If constriction by the centromere is “off center” between chromosomes, the chromosomes are classified as:

Answer 6

sub-metacentric

Question 7

What type of polymorphism is a variation in LINE1 and Alu sequences in the human genome?

Answer 7

Transposon Repeat Polymorphism

Question 8

Hemophilia A is associated with what CNV mechanism?

Answer 8

Gene interruption

Question 9

Of the 3 types of Tandemly Repeated Noncoding DNA, the _______ sequences are hot spots for mutations due to the frequent replication slippage.

Answer 9

microsatellite

Question 10

What is a karyogram?

Answer 10

standard format for depiction of a chromosome

Question 11

Approximately 45% of the human genome consists of transposable elements such as the _______ and ________.

Answer 11

1. long interspersed nuclear elements (LINEs)

2. short interspersed nuclear elements (SINEs)

Question 12

Which technique identifies a greater number of clinically significant cytogenetic alterations: chromosome microarray technology or traditional karyotyping?

Answer 12

Chromosome microarray technology

Question 13

What two arrays can be performed directly on uncultured tissue from CVS and amniocentesis?

Answer 13

1. CGH

2. SNP

Question 14

What technique detects chromosomal imbalances - increases or decreases in the amount of sequence in a region?

Answer 14

Comparative genome hybridization (CGH)

Question 15

Which technique detects sub-microscope deletions using the labeling of small DNA or RNA probes, allowing for characterization of more obvious chromosomal abnormalities associated with translocations, inversions, and deletions?

Answer 15

FISH

Question 16

What technique analyzes the presence and absence of submicroscopic regions of the genome?

Answer 16

qPCR - this is primarily used in cytogenetics when specific disease loci are in question

Question 17

Lisa and Bob have had three recurrent spontaneous abortions. In addition, they have a son, Richard, with dysmorphic features and an abnormal unbalanced karyotype. Lisa has been found to carry the following balanced translocation between: 3q12 and 11p15

Richard's karyotype is:
A.	46,XY,t(3;11)(q12;p15)
B. 	45,XY,t(3;11)(q12;p15)
C.	45,XY, der(3)t(3;11)(q12;p15)
D. 	46,XY,der(3)t(3;11)(q12;p15)
E.	46,XX,der(3)t(3;11)(q12;p15)

Answer 17

D.

Question 18

Which of the following karyotypes represents a pericentric inversion?

A. 46,XY,inv(11)(q13q22)
B. 46,XY,inv(3)(p23q27)
C. 45,XY,rob(14;21)(q10;q10)
D. 46,XX,del(4)(p15)

Answer 18

B. This includes the centromere!

Question 19

Which of the following karyotypes represents a paracentric inversion?

A. 46,XY,inv(11)(q13q22)
B. 46,XY,inv(3)(p23q27)
C. 45,XY,rob(14;21)(q10;q10)
D. 46,XX,del(4)(p15)

Answer 19

A.

Question 20

Which of the following karyotypes represents Wolf-Hischhorn syndrome?

A. 46,XY,inv(11)(q13q22)
B. 46,XY,inv(3)(p23q27)
C. 45,XY,rob(14;21)(q10;q10)
D. 46,XX,del(4)(p15)

Answer 20

D. This is a deletion on the short arm of chromosome 4, characteristic of Wolf-Hischhorn.