Question

Some cancers are consistently associated with the duplication of a particular part of a chromosome. What type of gene is most likely to be found in the duplicated region?

Answer 1

Gene duplication is a kind of mutation which involves producing one or more copies of a same gene or a specific region of a chromosome. Gene duplication is considered to be a mechanism associated with evolution. But, in certain cases extra copies of the genes may lead to different types of cancers.

In many sarcomas, the chromosoy region 12q 13-q14 is highly amplified. This region is responsible for encoding a binding protein known as MDM2. MDM2 binds to the tumor suppressor p53. p53 is involved in regulating the cell growth. If MDM2 is amplified, p53 is prevented from regulating the growth of the cell, which leads to formation of tumors.

ERBB2 Gene codes for Human epidermal growth factor receptor 2. Increased copy number and overexpression of ERBB2 is associated with breast cancers.

In addition to increased copy numbers of specific genes, increase of chromosome number like chromosome 1q & 3q are involved with greater risk if cancers.