A 45-year-old woman comes to the office due to 2 weeks of persistent back pain. She has also had excessive fatigue, anorexia, and unintentional weight loss over the past several months. The patient has no prior medical problems but has a history of cancer in the family. An imaging study reveals a lytic lesion in the T10 vertebral body. Analysis of the biopsy sample shows cell lineage with abnormally high replicative potential. A genetic study reveals a single nucleotide substitution causing an activating mutation. Which of the following genes is most likely involved in this patient's disease?

Question

A 45-year-old woman comes to the office due to 2 weeks of persistent back pain.  She has also had excessive fatigue, anorexia, and unintentional weight loss over the past several months.  The patient has no prior medical problems but has a history of cancer in the family.  An imaging study reveals a lytic lesion in the T10 vertebral body.  Analysis of the biopsy sample shows cell lineage with abnormally high replicative potential.  A genetic study reveals a single nucleotide substitution causing an activating mutation.  Which of the following genes is most likely involved in this patient's disease?

Quizplus · Accepted Answer

11ec160b_39f2_fdba_9249_dd317d0f5ea0_MD0001_00 Abnormal growth of neoplastic cells can arise due to mutation of either proto-oncogenes or anti-oncogenes (tumor suppressors). Proto-oncogenes stimulate cell proliferation, and their overexpression/amplification (eg, activating mutation) leads to increased cellular proliferation and neoplastic growth. KRAS is a proto-oncogene often activated in tumor cells, thereby increasing the cellular response to mitogenic stimuli. In contrast, anti-oncogenes are tumor suppressors as they inhibit cellular proliferation. Their inactivation (eg, loss-of-function mutation) contributes to tumor development. APC, BRCA1, RB, and TP53 are anti-oncogenes and are therefore more likely to be inactivated in neoplastic cells: Some of the important proto-oncogenes, anti-oncogenes, and their associated tumors are listed in the table. Educational objective: Most tumors possess multiple cytogenetic abnormalities. Activation of proto-oncogenes results in stimulation of cellular proliferation. Inactivation of anti-oncogenes eliminates oversight of the cell cycle.

A 45-Year-Old Woman Comes to the Office Due to 2