Question

What is the Philadelphia chromosome?

• A. A chromosome common between a gorilla and a man
• B. An abnormal chromosome found in the patients of certain blood cancers
• C. An extra chromosome found in the residents of Philadelphia
• D. A hypothetical chromosome thought to have been present in the Neanderthal man

Answer 1

Answer: (B)

An abnormal chromosome found in the patients of certain blood cancers

The Philadelphia chromosome or Philadelphia translocation (Ph) is a specific genetic abnormality in chromosome 22 of leukemia cancer cells (particularly chronic myeloid leukemia (CML) cells). This chromosome is defective and unusually short because of reciprocal translocation, of genetic material between chromosome 9 and chromosome 22, and contains a fusion gene called BCR-ABL1. Translocation results in an oncogenic BCR-ABL gene fusion that can be found on the shorter derivative 22 chromosome. This gene encodes for a BCR-ABL fusion protein. Depending on the precise location of fusion, the molecular weight of this protein can range from 185 to 210 kDa. Consequently, the hybrid BCR-ABL fusion protein is referred to as p210 or p185.

So the correct option is 'An abnormal chromosome found in the patients of certain blood cells'.