Gene Alterations, Mutations, chromosomal abnormalities.pdf

Altered Gene mutations, Genetics, genetic abnormalities, translocation, mutations, types of mutations, germline or hereditary mutations, somatic or acquired mutations, inversion, duplication, non disjunction, point mutation, application

1. GENE ALTERATIONS
V GANAPATHI
PHARM D
PHARMACOLOGY II
WITH THE HELP OF……
DR. SYEDANISHATFATHIMA
M. PHARM, PH. D

2. ALTERED GENE FUNCTIONS
➢Change in the function of gene, which may contribute to the development or spread of cancer.
➢Genetic alterations include chromosomal abnormalities and gene mutations
➢Chromosomal abnormalities: arise during cell division involving number of chromosomes,
structural or some with genetic disorder or diseases like cancer
➢Gene mutation : these are permanent changes in DNA gene sequence
➢They can arise during normal DNA replication or in response to environmental factors

3. GENETIC (CHROMOSOMAL) ABNORMALITIES
➢Often occur during cell division (meiosis & mitosis)
➢There are two main groups of chromosomes –Numeric and Structural
➢Numeric: As the name suggests, involves the number of chromosomes
➢Monosomy –occurs when one of the two chromosomes are missing from a pair .
Ex:-Turner syndrome , in which part or all of a female’s second X –chromosome is missing
➢Trisomy –occurs in individuals with an extra chromosomes
Ex:-Down syndrome , have three copies of chromosome 21 instead of two copies

5. MUTATIONS
➢A gene mutation is a permanent change in the DNA sequence of a gene. Mutation can occur in a single base pair or
in a large segment of a chromosome and even span multiple genes.
➢Mutation can result from endogenous (occurring during DNA replication) or exogenous (environmental ) factors
➢There are two main categories of mutations ;
Germline and somatic

6. GERMLINE (HEREDITARY) MUTATIONS
➢Germline mutations are inherited from a parent
➢A person with a germline mutation will have the mutation in every cell in the body.
➢Germline mutations are the cause of some diseases such as Cystic fibrosis and cancer(breast , ovarian and
melanoma)
➢CYSTIC FIBROSIS : is a hereditary genetic disorder that results in a thick , sticky buildupof mucus in the Lungs ,
Pancreas and other organs.
➢Cystic fibrosis is the most common genetic disease & arises from a mutation in a single gene named the CFTR
(cystic fibrosis transmembranaseregulator gene).

7. SOMATIC (ACQUIRED) MUTATION
➢Somatic mutations can occur at any point in a person’s life .
➢These mutations are often caused by environmental or lifestyle factors and
can also result from mistake during cell division.
➢This type of mutation is not passed down from parents to children and thus is not
present in every cell in the body

8. TYPES OF MUTATIONS
➢DELETION :
➢Due to breakage
➢A piece of a chromosome is lost

9. INVERSION
➢Chromosome segment breaks off
➢Segment flips around backwards
➢Segment reattaches

10. DUPLICATION
➢Occurs when a gene sequence is repeated

11. TRANSLOCATION
➢Involves two chromosomes that aren’t homologous
➢One part of chromosome is transferred to another
chromosome

12. NON DISJUNCTION
➢Failure of chromosomes to separate during meiosis
➢Causes gamete to have too many or too few
chromosomes
➢Disorders : down syndrome ,turner syndrome ,
Klinefelter’s syndrome

13. POINT MUTATION
➢Point mutation involve the substitution of one base
for another
➢Sickle cell disease is the result of one nucleotide
substitution
➢Occurs in the Hemo-globin gene

14. AMPLIFICATION
➢An increase in the number of copies of a gene.
➢There may also be an increase in the RNA and protein made from that gene
➢Gene amplification is common in cancer cells and some amplified genes may cause cancer cells to grow or become
resistant to anticancer drugs.

15. THANK YOU