What is the role of inactive MLH1 in the development of some forms of inherited colon cancer?

a. Deletion of a nucleotide repeat in the DUX4 gene.
b. DNA damage is left unrepaired.
c. Expansion in the number of cyto-sine-guanine (CG) dinucleotide.
d. Abnormalities of chromosome 11p15.5 that lead to downregulation of IGF2.


ANS: B
A major cause of one form of inherited colon cancer (hereditary nonpolyposis colorectal cancer [HNPCC]) is the methylation of the promoter region of a gene, MLH1, whose protein product repairs damaged DNA. When MLH1 becomes inactive, DNA damage accumulates, eventually resulting in colon tumors. Facioscapulohumeral muscular dystrophy (FSHMD) is associated with the DUX4 gene. Fragile X is associated with the cytosine-guanine (CG) dinucleotide. Downreg-ulation of IGF2 is associated with Russell-Silver syndrome.

Nursing

You might also like to view...

While assessing the development of a nine-month-old infant, the nurse asks the mother if the child actively looks for toys when they are placed out of sight. The nurse is trying to determine whether the infant has developed:

1. Transductive reasoning 2. Conservation 3. Centration 4. Object permanence

Nursing

A 30-year-old African American had surgery 6 months ago. Her incisional site is now raised, indurated, and shiny. This tissue growth is most likely a(n)

a. angioma. b. keloid. c. melanoma. d. nevus.

Nursing

A nurse clarifies that electrolytes, such as sodium and potassium (K+), break down into smaller particles when dissolved. What are these smaller particles?

a. Cells b. Elements c. Ions d. Molecules

Nursing

Which of the following disorders would lead the health care provider to question an order for spironolactone (Aldactone)?

a. Primary aldosteronism b. Edema due to cirrhosis c. Anuria due to renal failure d. Nephrotic syndrome

Nursing