When a member of Rozen's team spotted
the same type of mutation in liver cancer, the group wondered if plants that contain aristolochic acid might increase a person's risk of developing the disease.
Everyone with Huntington's disease has inherited
the same type of mutation from their mother or father, an extra-long repetitive stretch of the sequence C - A-G in their HD gene.
Not exact matches
«Just as normal cells with the
same genome differentiate into many different cell
types, a single tumor characterized by specific genetic
mutations can contain many different
types of cells — stem - like and more differentiated cells — with the difference being rooted in their epigenetic information.
This is important because the proportion in which the de novo
mutation is present in a patient, as well as the
type of cells in which it occurs, may not only determine the clinical outcome
of a disease for the patient, but also affect the risk
of the parents having another child with the
same disease in future pregnancies.
«We call this
type of mutation a complex indel because insertion and deletion is happening at the
same time, in the
same genomic location,» Ding said.
But in 2010, Stephen Rossiter, an evolutionary biologist at Queen Mary, University
of London, and his colleagues determined that both
types of echolocating bats, as well as dolphins, had the
same mutations in a particular protein called prestin, which affects the sensitivity
of hearing.
With the help
of modern genetic technology and the resources
of the International Rice GeneBank, which contains more than 112,000 different
types of rice, evolutionary biologist Kenneth Olsen, PhD, associate professor
of biology in Arts & Sciences at Washington University in St. Louis, has been able to look back in time and ask whether the
same mutations underlay the emergence
of the
same traits in both cultivated and weedy rice.
This finding provides an explanation for how the
same cancer - causing
mutation can give rise to different
types of brain malignancies.
Neil Johnson's lab at the Fox Chase Cancer Center examined treatment resistance in breast cancer cells expressing the
same BRCA1185delAG
mutation and determined that the RING - deficient BRCA1 protein was also responsible for loss
of sensitivity to certain
types of cancer treatments.
Both teams found that
mutations to the
same gene can also cause a common
type of dementia called frontotemporal dementia (FTD).
Sometimes, two patients with the
same type of cancer may be dealt different prognoses depending on their genetic
mutations.
By assessing the incidence
of a particular
mutation or the frequency at which certain genes / pathways are altered across multiple patients (
of the
same tumor
type), it should be possible to identify key
mutations.
The challenge is that these
mutations are «personal» to the tumor and patient; i.e., not all
types of breast cancer carry the
same set
of mutations, and as a result, different patients have a different, personal set
of mutations.
The Cancer Gene Census (CGC) database contains 547 such gene across various cancer
types.5 Remarkably, few driver genes having specific point
mutations appear to be sufficient to rewire signalling networks in cancer, 1 which at the
same time shows that — at least from the mutational side — cancer does not consist
of an «infinite» number
of different diseases, and in many cases treatment options targeted against driver genes might be transferred from one case to the next.