Answer to Question #116296 in Genetics for MAKHUOGA ALFRED FRIDAY

Question

Identify the different types of chromosomal abnormalities that can lead to disease (e.g. insertions) and in a sentence or two, describe a disorder associated with one of these aberrations.

Answer 1

The chromosomal abnormalities comprise mutations associated with the impairment of the chromosomal structure. These mutations and associated diseases include:

1. deletions are characterized by the loss of a portion of a chromosome. Jacobsen syndrome results in the deletion of a part of chromosome 11 leading to the development of congenital disorder associated with dysmorphic features, intellectual disabilities, heart defects, etc.
2. duplications are caused by the duplication of the certain portion of a chromosome. For example, Pallister Killian syndrome is characterized by the duplication of a short arm of chromosome 12 and is associated with weak muscle tone, intellectual impairment, distinct facial features, developmental delays, etc.
3. translocations are mutations caused by the exchange of portions of chromosomes between two or more chromosomes. Translocation between chromosomes 9 and 22 leads to the formation of the Philadelphia chromosome resulting in the development of leukemia cancer.
4. inversions are characterized by the inversed attachment of a chromosome part. Chromosome 9 inversion causes Walker-Warburg syndrome associated with serious developmental defects of muscles, brain, and eyes.
5. insertion is associated with the transfer of DNA fragment adding new genetic material to a certain chromosome. Charcot-Marie-Tooth Neuropathy CMTX3 is caused by the insertion of a portion of chromosome 8 into chromosome X leading to the development of motor and sensory neuropathies associated with the loss of muscle tissues.