Genetics: Differentiate between proto-oncogenes and tumor suppressor genes

retinoblastoma mutation pattern?

1. May be sporadic (very rare & occurs unilaterally). 2. May be Inherited (occurs bilaterally)

Uncontrolled cell proliferation

An oncogene does not respond to normal growth restraints, leading to _______________?

Recessive

Expression at the gene level is _________. Meaning → if a woman carries ONE (1) mutant copy of BRCA1 or BRCA2, she has a predisposition to breast cancer

Both

For cancer to develop, how many copies of BRCA1 or BRCA2 must be mutant alleles?

Tumor Suppressor Genes

Genes that turn OFF or DECREASE the rate of cell division. Genes that repair DNA mistakes. Genes that play a role in apoptosis.

Proto-oncogenes

Genes that turn ON or INCREASE the rate of cell division. When these genes are active CELLS GROW and DIVIDE. When normal cells stop dividing, the genes turn off.

Tumor Suppressor Genes

If these genes mutate or are inactivated, cells pass through the checkpoints and divide in an uncontrolled manner which may lead to abnormal cell growth and defective apoptosis - all which can cause cancer

missense mutation (single letter change)

Most often when a mutation occurs in a proto-oncogene it is due to what type of mutation?

DNA repair

Normal BRCA1 and BRCA2 are both involved in what?

Gatekeeper genes

Proto-oncogenes and Tumor suppressor genes

Autosomal dominant

The Predisposition to breast cancer, caring 1 one mutant copy of BRCA1 or BRCA2, is inherited as an __________________ trait.

BRCA1 and BRCA2

The gene mutations that can lead to breast/ovarian cancer.

Oncogene

When a mutation occurs in a proto-oncogene that permanently "turns it on" it can become a __________.

BRCA1 and BRCA2

b/c the genes are involved in DNA repair, if either of these genes are mutated, DNA is unable to be repaired, therefore mutations accumulate within a cell and initiate transformation from a normal cell to a cancerous one.

retinoblastoma

is the result of an RBI tumor suppressor gene mutation .

one. Therefore, proto-oncogenes are DOMINANT.

proto-oncogenes need how many mutation to cause cancer?