The document discusses sexual aneuploidy, which is an abnormal change in the number of sex chromosomes. It normally occurs during cell division when the chromosomes do not separate properly. There are five main types of sexual aneuploidy discussed: Klinefelter syndrome, Turner syndrome, Jacob's syndrome, Metafemale syndrome, and Lethal syndrome. Each syndrome is characterized by having an extra or missing sex chromosome, which can cause physical and developmental effects. The document also provides an example probability problem calculating the likelihood of abnormal and normal children from parents with Jacob's and Metafemale syndromes.

1. SEXUAL ANEUPLOIDY
Lascano, Joshua Ruel A.
Puno, Jasmine Nicole S.

2. Every cell in the human has 23
pairs of chromosomes (for a
total of 46). One copy of each
pair is inherited from the
mother and the other copy is
inherited from the father. The
first 22 pairs of chromosomes
(referred to as autosomes)are
numbered from 1 to 22. The
23rd pair of chromosomes are
the sex chromosome. Normal
females have two X-
chromosomes (XX), while
normal males have one X-
chromosome and one Y-
chromosome (XY).

3. When Non-
disjunction of
chromosome
happened, the
chromosomes did
not separate
perfectly causing
some chromosomes
to go to the other
pole.
NON-DISJUNCTION OF CHROMOSOME

4. Aneuploidy is the
term used when
there is a change in
number of
chromosomes.
Aneuploidy occurs
during cell
division when the
chromosomes do
not separate
properly between
the two cells.
ANEUPLOIDY

5. Sexual
Aneuploidy
occurs when
there is an
abnormal change
in the number of
sex chromosome.
SEXUAL ANEUPLOIDY

6. Monosomy (2n -1)
-it refers to lack of one chromosome of the normal complement
Disomy (2n)
-disomy is the presence of having two copies of chromosome. In
humans, that have two copies of each chromosome(diploid), it is a normal
condition.
Trisomy (2n +1)
- it is a condition where there is an extra one chromosome either in the
autosomes or sex chromosomes
Tetrasomy (2n + 2)
-it is a condition where there is two extra chromosomes
Pentasomy (2n + 3)
-it is a condition where there is three extra chromosomes
TERMINOLOGY

7. Sexual Aneuploidy:
5 COMMON ABNORMALITIES

8. It is an abnormal condition that only
occurs in males having an extra X-
chromosome, having 47 total
number of chromosomes (44xxy)
Characteristics:
Enlargement of breast
Under developed testes (sterile)
Mild-mental Impairment
If for instance they are not sterile,
they can produce sperm cells that
are:
22x (Normal)
22y (Normal)
22xxy
KLINEFELTER SYNDROME

9. It is an abnormal condition that
happens only in females lacking
either Y-chromosome or X-
chromosome and having only one
sex chromosome (X-chromosome),
having a total 45 chromosomes
(44x)
Characteristics:
Webbed-necked
Flat-chested
Does not exhibit sexual
maturation(sterile)
If for instance they are not sterile,
they can produce ovum that are:
22(no sex chromosome)
22x (Normal)
TURNER SYNDROME

10. An abnormal condition that occurs
only in males, having an extra Y-
chromosome resulting for a total
number of 47 chromosomes
(44xyy)
Characteristics:
Usually violent
Antisocial/Uncontrolled temper
High testosterone level
They are usually fertile, and
produces sperm cells that are:
22x (Normal)
22y (Normal)
22yy
22xy
JACOB’S SYNDROME

11. An abnormal condition that only
occurs in females that possesses
an X-chromosome, having a total of
47 chromosomes (44xxx)
Characteristics:
Generally has a normal
appearnace due to Barr
Bodies(inactive X-chromosome)
Lower female ability (sterile)
If for instance they are not sterile,
they can produce ovum that are:
22x (Normal)
22xx
METAFEMALE SYNDROME

12. It is a fatal syndrome that only
occurs in male, lacking an X-
chromosome(chromosome for life)
and only having a Y-chromosome,
having a total number of 45
chromosome (44y)
X-chromosome is also called
chromosome for life because it
carries most of the physiological
characteristics.
LETHAL SYNDROME

13. SAMPLE PROBLEM

14. IF, FOR EXAMPLE, A PERSON HAS A JACOB’S
SYNDROME MARRIES A PERSON THAT HAS A
METAFEMALE SYNDROME, ASSUMING SHE IS
FERTILE. WHAT IS THE PROBABILITY OF HAVING
A NORMAL CHILD AND 3 ABNORMAL
CHILDREN?

15. JACOB’S(44XYY) X METAFEMALE(44XXX)
22X 22X 44XX (NORMAL FEMALE)
44XXY (KLINEFELTER)
22XY 44XY (NORMAL MALE)
44XYY (JACOB’S)
22Y
22YY 22XX 44XXX (METAFEMALE)
44XXXY (KLINEFELTER)
44XXY (KLINEFELTER)
44XXYY(JACOB’S)
JACOB’S = 2/8
KLINEFELTER = 3/8 ABNORMAL ( 6/8 OR 3/4)
METAFEMALE = 1/8
MALE= 1/8
FEMALE = 1/8 NORMAL ( 2/8 OR ¼)

16. P= n! RATIO: 3:1 OR (3/4)(1/4)
A! (n – A)!
WHERE :
A - ABNORMAL NORMAL MALE(1/2)
n – TOTAL NUMBER OF CHILDREN NORMAL FEMALE (1/2)
P = 4! 4(1) (3) 3
3! (4 – 3)! 4 4
P = 4X3X2X1 = 4(1) (27)
3X2X1 (1)! 4 64
=4 (27)
P=4 = 4(N)(A) 3 256
1
= 108 OR 27
256 64

17. NOTE:
IN THE EQUATION, THE TOTAL NUMBER USED IS 4 WHERE
THE TOTAL NUMBER OF CHILDREN IS 8. WE USED 4 BECAUSE OF
THE RATIO INDICATED AND BASE FROM THE PROBLEM WHERE
THE ABNORMAL CHILDREN IS 3 AND THE NORMAL CHILD IS 1.
ONE THING SHOULD BE REMEMBERED IS THAT THE ANSWER
SHOULD ALWAYS BE EXPRESSED IN THE LOWEST TERM.

18. THE END