CHROMOSOMAL ABERRATIONS (identification using karyotyping) Prepared by: Mr. Nikko Lorenz P. Lawsin MASEd Biology
CHROMOSOMAL ABERRATIONS(identification using karyotyping)
Prepared by:Mr. Nikko Lorenz P. Lawsin
MASEd Biology
C H R O M O S O M E S
D I S J U N C T I O N
E X C E S S
L A C K I N G
T R A N S L O C A T I O N
D E L E T I O N
D U P L I C A T I O N
I N V E R S I O N
Causes:1. Non-disjunction in Meiosis
2. Inability of the Spindle fiber to attract the chromosomes.
Based on Chromosomal Number
(Euploidy or Aneuploidy)
Based on structure
CHROMOSOMAL ABERRATIONS
Euploidy – Sets of Chromosomes alterations. If 2n is normal,Therefore,3n is TRIPLOID4n is TETRAPLOID
Aneuploidy – single number alterationsExample, if 2n is normal,2n + 1 is Trisomy
Trisomy (2n + 1) In human, 46 Chromosomes (23
pairs) 2(23) + 1 = 47
Trisomy 21 – Down syndrome Trisomy 18 – Edward Syndrome Trisomy 13 – Patau Syndrome Trisomy 23 (XXY) – Klinefelter’s
syndrome
Monosomy (2n - 1) In human, 46 Chromosomes (23 pairs) 2(23) - 1 = 45
XO syndrome (Turner’s syndrome) – defiency of X or Y in sex chromosomes
Monosomy in autosomes is not viable
Double Trisomy (2n + 1) + 1
In human, 46 Chromosomes (23 pairs) [2(23) + 1 ] + 1= 48
Tetrasomy (2n + 2)
In human, 46 Chromosomes (23 pairs) 2(23) + 2 = 48
Nullisomy (2n - 2) In human, 46 Chromosomes (23
pairs) 2(23) - 2 = 44
Based on Structure
Deletion Inversion Translocation Duplication
Deletion
Deletion of DNA or Chromosomes’ part or segment
Deletions
A B C D E F G H I J K L
The TRAITS that are controlled by the genes of JKL, are missing which might result to some disorders.
A B C D E F G H I
NORMAL
DELETED
Duplication
Duplication of DNA or Chromosomes’ segment
DUPLICATION
A B C D E F G
The TRAIT(s) that is/are controlled by the genes of CDE is duplicated which may also produce aberration such as polymorphism
A B C D E C D E F G
NORMAL
DUPLICATED
Translocation
Transfer of Chromosome’s segment into non-homologous chromosomes
TRANSLOCATION
A B C D E F G H I
EFG gene which controls other trait(s) might not be functional since it displaced into another locus.
A B C D H I
NORMAL
TRANSLOCATED
V W X E F G Y Z
CHROMOSOME #4
CHROMOSOME #4
CHROMOSOME #8
Identify the ff. chromosomal aberrations
based on number &
structure using the ff. karyotype
Trisomy 23 (XXY) or Klinefelter Syndrome
Trisomy 21 (XXY) or Down Syndrome
Triploid
Trisomy 18 (XXY) or Edward Syndrome
Trisomy 21 (XXY) or Down Syndrome
Tetraploid
Monosomy (X0) or Turner Syndrome
Trisomy 23 (XXY) or Klinefelter Syndrome
Trisomy 13 (XXY) or Patau Syndrome
Trisomy 13 (XXY) or Patau Syndrome
Tetrasomy
Double Trisomy
A B C D E F G H I J K L
The TRAITS that are controlled by the genes of JKL, are missing which might result to some disorders.
A B C D E F G H I
NORMAL
????
A B C D E F GA B C D E C D E F G
NORMAL
????
A B C D E F G H I
EFG gene which controls other trait(s) might not be functional since it displaced into another locus.
A B C D H I
NORMAL
????
V W X E F G Y Z
CHROMOSOME #4
CHROMOSOME #4
CHROMOSOME #8
POST-ACTIVITY: CREATE YOUR OWN KARYOTYPE
QUIZ TIME
QUIZ TIME: Solve this problem with complete solution
There are 52 chromosomes in a normal cell of unknown organisma. Identify the number of chromosomes of a haploid cell (n). (2pts)b. Identify the aberrations of the following chromosomes
considering the given above. Show your solution. b.1 104 chromosomes (2pts) b.2 53 chromosomes (2pts) b.3 50 chromosomes (2pts) b.4 78 chromosomes (2pts)