genetic disorders

1. GENETIC
DISORDERS

2. A change in the
number or structure
of chromosomes can
dramatically change
the traits of an
organism and can
cause serious
problems.

3.  Abnormal chromosomes most
often happen as a result of an
error during cell division.
Chromosome abnormalities
often happen due to one or
more of these:
 ➢ Errors during dividing of sex
cells (meiosis)
 ➢ Errors during dividing of
other cells (mitosis)
 ➢ Exposure to substances that
can cause birth defects
(teratogens)

5. is the process by which photographs of
chromosomes are taken in order to
determine the chromosome
complement of an individual, including
the number of chromosomes and any
abnormalities.

6. Numerical abnormality also called
aneuploidy, a condition which occurs
when an individual has a missing
chromosome from a pair (monosomy)
or has more than two chromosomes
of a pair (trisomy, tetrasomy, etc.).
NUMERICAL
ABNOMALITY
Aneuploidy

8. Down Syndrome (Trisomy 21)
Turner Syndrome (45, XO)
Klinefelter Syndrome (47, XXY)
Trisomy X Syndrome (47, XXX)
Patau Syndrome (Trisomy 13)
Edward Syndrome (Trisomy 18)

9. occur when the chromosome’s structure is altered, which
can take several forms such as:
Deletion – a portion of a chromosome is missing or
deleted;
Duplication – segment of a chromosome is repeated
twice;
Translocation – transfer of a section of one chromosome
to non-homologous chromosome;
Inversion – a section of the chromosome becomes
changed by rotation at 180 degrees.

10. Cri-du-chat
Syndrome (5p
minus syndrome)

12. ✓ The most common disorder of
trisomy is Down syndrome, wherein
the 21st chromosome has three instead
of two chromosomes.
✓ Most cases of Down syndrome are
not due to inheritance but on random
mistakes during formation of
reproductive cells of the parents.
✓ Physical manifestations: Short neck,
with excess skin at back of the neck.
Flattened facial profile and nose.
Small head, ears, and mouth. Upward
slanting eyes.

13. ✓ A condition that affects only
female as a result of one of the X
chromosomes (sex chromosome) is
missing or partially missing.
✓ Physical manifestations: Webbed
neck, short stature, swollen hands
and feet. Some have skeletal
abnormalities, kidney problems,
and/or congenital heart defect.

16. ✓ A condition resulting from two or more X
chromosomes in males
✓ Manifestations are typically more severe if
three or more X chromosomes are present as in
(48, XXXY) or (49, XXXXY).