Transcript Mutations - Duplin County Schools

Mutations
• A mutation is a permanent change in the
DNA sequence of a gene.
• Mutations in a gene's DNA sequence can alter
the amino acid sequence of the protein
encoded by the gene.
GOOD
BAD
NEUTRAL
Chromosome Mutations
(point, deletion, translocation, )
•
Mutation of MSTN Gene
What genes are related to myostatin-related
muscle hypertrophy?
• Mutations in the MSTN gene cause myostatinrelated muscle hypertrophy. The MSTN gene
provides instructions for making a protein called
myostatin, which is active in muscles used for
movement (skeletal muscles) both before and
after birth. This protein normally restrains muscle
growth, ensuring that muscles do not grow too
large. Mutations that reduce the production of
functional myostatin lead to an overgrowth of
muscle tissue.
Desirable Mutation
Desirable Mutations in Animals
U
Causes of Mutations
Radiation
Chemicals
Smoking
Ultra-violet Rays
SKIN CANCER
• Skin cancer occurs when errors (mutations)
occur in the DNA of skin cells. The mutations
cause the cells to grow out of control and
form a mass of cancer cells.
Melanoma (BRAF mutation)
Mutations Caused by Radiation
Fallout
Mutations Caused by Chemicals
Mercury in the environment
Sickle Cell Anemia
Actress Angelina Jolie has revealed
that she had a double mastectomy
after she learned that she carries a
mutated version of the gene BRCA1
and had a very high risk of breast
cancer. She explained her decision in
a New York Times article. Here are
some questions her story may raise
for other women.
Q: What is the BRCA1 gene?
A: BRCA1 (pronounced brak-uh) stands for
“breast cancer one.” It was the first mutated
gene that scientists discovered among families
whose histories revealed many cases of breast
cancer, including cancers at early ages and in
both breasts. Ovarian cancers also are common
in such families, according to the Stanford
Medicine Cancer Institute. A second such gene is
known as BRCA2.
• Q: How high is the cancer risk in women who
carry the mutations?
• A: Women with the BRCA1 or BRCA2 mutations
have an average breast cancer risk of 60 percent,
according to the NCI. Men with the mutations
also have higher breast cancer risks than other
men do. But personal risk can vary, based on
family history and other factors. Jolie, whose
mother died of ovarian cancer at age 56, says her
personal risk was estimated at 87 percent.
• Q: Should all women be tested for these
mutations?
• A: No. As Jolie notes, the tests can be expensive.
The results also can have immense psychological
and medical fallout and raise issues about privacy
and discrimination.
Plant Mutation