This is the poerpoint slideshow of Dr. Saima Mansoor Bugvi.

1. Karyotypes
and
Karyotyping

2.  Chromosomes in a cell are visible only when
the cell is dividing
 At metaphase stage chromosomes are
fully condensed and easy to see.
 Metaphase spreads are selected and
photographed in order to analyze
 The chromosomes are then arranged in
homologous pairs.

3.  Thehomologous pairs are then placed in
order of descending size. The sex
chromosomes are placed at the end.
A picture of chromosomes arranged in this
way is known as a karyotype.

5.  Each chromosome should be individually
located.
 A detailed comparison of banding pattern is
mandatory between the two homologues.
 Telomeres are specially important.
 To ensure the best interpretation, it is
important to provide some clinical information.

6. A “normal” human carries 23 PAIRS of
chromosomes (1 set came from the mother, 1
set came from the father)
 22 of these sets are called autosomes (or “self
chromosomes”)
 1 set are the sex chromosomes
 A female carries two X chromosomes (XX)
 A male carries an X chromosome and a Y chromosome
(XY)
Mazen Zaharna Molecular Biology 1/2009

7.  To label a karyotype correctly, first list the
number of chromosomes found in the
karyotype. Ex. 46
 Secondly, list the type of sex chromosomes
found in the karyotype. Ex. XX
 Lastly, list the any abnormalities at the
appropriate chromosome number.

8. Normal Human Female:
46, XX
Normal Human Male: 46,
XY

10.  Size
Human chromosomes range in length from 51
million to 245 million base pairs. They are
numbered from largest to smallest

11. Position of centromere
metacentric
submetacentric
acrocentric

12.  Banding pattern
each chromosome has a unique banding pattern
Chromosomal bands are alternating light and dark
segments that result from various staining
procedures.
 two strong bands on the
P-arm
Three strong bands near
the bottom of the q-
arm The band width and the order of bands is
characteristic of a particular chromosome - a
trained cytogeneticist can identify each
chromosome (1,2,3...22, X and Y) by observing
its banding pattern under the microscope.

13.  Group A: chromosomes 1,2,3
largest
metacentric
 Group B: chromosomes 4,5
large
submetacentric
 Group C: chromosomes 6,7,8,9,10,11,12
medium
submetacentric

14.  Group D: chromosomes 13, 14, 15
medium
acrocentric
 Group E: chromosomes 16, 17, 18
short
metacentric or submetacentric
 Group F: chromosomes 19, 20
short
metacentric
 Group G: chromosomes 21, 22
very short
acrocentric
Mazen Zaharna Molecular Biology 1/2009

15.  Allows any region to be
identified by a descriptive
address (chromosome
number, arm, region, and band)
 Standard nomenclature is to
include the translocation in one
set of parentheses and the
breakpoints in a second set of
parentheses. Thus, this specific
translocation would be denoted
as t(9;22)(q34;q11.2).

16.  Numerical
Extra chromosome
missing chromosomes
 Structural
Translocations
Inversions
Deletions
Duplications
Mazen Zaharna Molecular Biology 1/2009

17.  Polyploidy – extra set of the entire genome.
 (3n, 4n etc)
 Aneuploidy – the number of chromosomes is
not a multiple of the normal haploid number.
 Monosomy
 one member of a chromosome pair is
missing, (2n-1)
 Trisomy
 one chromosome set consists of 3 copies of a
chromosome, (2n+1
Mazen Zaharna Molecular Biology 1/2009

18. Translocations
when a portion of a chromosome breaks off and
rejoins with another chromosome, a common
occurrence in leukemias).
Inversions
Chromosomal inversion (inv) requires two breaks in
the same chromosome with rotation of the
intervening material.
Deletions
part of the chromosome has been removed
Duplications
part of the chromosome is duplicated

19. Translocation Deletion Inversion Isochromosome
Insertion Ring
Derivative
chromosome chromosome

21. The malignant cells in many patients with
leukemia, lymphoma, or another malignant
hematologic disease have acquired clonal
chromosomal abnormalities.
Some specific cytogenetic abnormalities are
closely, and sometimes uniquely, associated
with morphologically and clinically distinct
subsets of leukemia or lymphoma, as well as
with their prognosis.

22.  The marrow chromosomes were more
difficult to grow, contracted chromosomes
with ill defined morphology
 Assisting in the diagnosis and classification of
certain malignant hematological disorders
 Evaluation of prognosis in patients with
certain malignant hematologic disorders
 Monitoring effects of treatment
 Monitoring patients in remission

23. - 8;14 translocation
 - 4;11 translocation
 t(11q23) ALL in infants)
 - 9;22 translocation
 - 1;19 translocation in pre-B cell ALL
 - 12;21 translocation in precursor B ALL
 - Hyperdiploidy
 - Hypodiploidy
 - 9p abnormalities in ALL

24.  12;21 is the most common translocation and
pretends a good prognosis.
 4;11 is the most common in children under 12
months and pretends a poor prognosis

25.  There are substantial differences between
children and adults with ALL in the
frequencies of some recurring
abnormalities, including the following:
 The t(9;22) is observed in about 2 to 5
percent of children compared with about 30
percent of adults

26.  The t(12;21), which is detectable only by FISH or
polymerase chain reaction (PCR) analysis, is
observed in about 25 percent of children with B-
lineage leukemia , compared with about 3
percent of adults.
 A hyperdiploid karyotype is found in 30 to 40
percent of children compared with 2 to 10
percent of adults
 t(4;11) is present in up to 60 percent of infants
younger than 12 months, but is rarely observed
in adult ALL patients

27.  certaintranslocations, such as
t(4;11) and t(9;22), hyperdiploidy (50 to 60
chromosomes) favorable outcome
t(12;21), t(1;19)
treatment failure even when using intensive
chemotherapy

28.  Case no.
 78 Year-old Female
 Leukoerythroblastic Film
 Indication :
Myelodysplasia/Myeloproliferative syndrome

30.  Report
 Chromosome analysis of the cultured bone
marrow cells reveals an abnormal karyotype
with an additional copy of chromosome 8 in
all ten cells examined. 07 of these ten cells
have in addition an extra copy of
chromosome 19.
 Trisomy 8 is a common finding in myeloid
disorders including MDS and MPD, but is not
specific for any particular disease type.
 This result shows evidence clonal evolution.

32.  Report
 47,XXdel(6),der(12)t(1;12),+21
 There is deletion of long arm of chromosome
6 and an unbalanced translocation between
the long arms of chromosome 1 and 12. This
has resulted in partial Trisomy for the long
arm of chromosome 1 and partial monosomy
for the chromosome 6.
 AML in children with Down Syndrome is
recognised as a distinct identity.
 Both dup(1q) and del(6q) are frequent
imbalances in Downs Syndrome cases of AML.

33.  The characteristic abnormality in CML is
t(9;22)(q34;q11.2)
 The classic t(9;22)(q34;q11.2) rearrangement
occurs in 90-95% of chronic myelogenous
leukemia (CML).
 Karyotype changes associated with increase
of fibers in Ph 1-positive cases of CML were
trisomy 8 and 19, +Ph1, t (1; 11), and i (17q).
Ph 1-positive CML patients with additional
karyotype changes had a significantly shorter
survival than Ph 1-positive patients without
additional chromosome aberrations.

34.  Case
 70 Year-old Women known CML.

36.  46XX,t(1;12)(p36;q15),t(9;22)(q34;q11)[20]
 There is a Philadelphia chromosome. All cells
also have a translocation between the short
arm of chromosome 1 and the long arm of
chromosome 12.

37.  The single most important prognostic factor in
AML is cytogenetics, or the chromosomal
structure of the leukemic cell.
 Certain cytogenetic abnormalities are
associated with very good outcomes (for
example, the (15;17) translocation in acute
promyelocytic leukemia)
 About half of AML patients have "normal"
cytogenetics; they fall into an intermediate risk
group.
 A number of other cytogenetic abnormalities are
known to associate with a poor prognosis and a
high risk of relapse after treatment.

38.  t(8;21)(q22;q22)
 t(15;17)(q22;q12
 Inv(16) and t(16;16)
Rearrangements of 11q23
 t(3;3) and inv(3)
 t(6;9)
 t(1;22)
 Chromosomal gain and loss

39. FAB subtypes show consistent chromosome changes.
 t(8;21)(q22;q22
93% belong to the M2 and the remaining 7% are M4
 t(15;17)(q22;q12
diagnostic of M3
 Inv(16) and t(16;16)
Inversion or deletion of chromosome 16 is diagnostic
of eosinophilia in association with M4
 Rearrangements of 11q23
Deletions of 11q are frequently associated with M5

40.  Favorable
t(8;21), t(15;17), inv(16)
 Intermediate (Most patients)
normal, +8, +21, +22, del(7q), del(9q),
 Adverse
-5, -7, del(5q), abnormal 3q,
complex karyotype (> 3 -5 abnormalities)

41. 7 Year-old Girl new AML.
 Indication :AML unspecified.

43.  46XX,inv(16)(p13q22)[4]/47,+22[6]
 Female karyotype with a pericentric
inversion of chromosome 16 in all ten cells
examined. Six of these cells also have an
extra copy of chromosome 22.
 Inv(16) is most often reported in AML M4 with
eosinophilia and is usually associated with a
favourable prognosis. Additional
abnormalities, such as trisomy 22, can be
detected at diagnosis but do not appear to
affect the prognosis.

47.  Approximately 80% of individuals with CLL
have acquired chromosomal abnormalities
within their malignant clone and can be
categorized into five prognostic groups
accordingly:
 deletion 13q (median survival, 133 months)
 deletion 11q (median survival, 79 months)
 trisomy 12 (median survival, 114 months)
 normal cytogenetics (median survival, 111
months
 deletion 17p (median survival, 32 months)

48.  Deletion 13q is found in ~55% of
patients, making it the most common
cytogenetic abnormality in CLL
 Deletion 11q is identified in ~18% of CLL
patients and is associated with several
adverse prognostic factors including
extensive lymphadenopathy, unmutated
IgHV, advanced disease at diagnosis, poor
response to treatment, and shorter
progression free survival

49.  Trisomy 12 is found in ~16% of CLL, and
 normal cytogenetics ~18% of CLL patients
As intermediate prognostic indicators
 Deletion 17p is found in ~7% of CLL patients
and confers the highest risk poor prognostic
indicator. Deletion 17p is a poor prognostic
factor

50. A complex cytogenetic karyotype can be
identified in ~16% of patients and is
commonly associated with poor prognostic
features
 Reciprocal chromosome translocations are
described but rare in CLL

51. 47,XY+5(Del)9