CAG

CAG is an acronym and a three-nucleotide sequence that appears in genetics, medicine, and government. It can denote a specific DNA triplet, cytosine-adenine-guanine, as well as several widely used abbreviations in public administration and oncology.

In genetics, CAG codes for the amino acid glutamine. In the standard genetic code, codons for glutamine include CAA and CAG. CAG is also notable for its role in trinucleotide repeat disorders: expansions of CAG repeats within certain genes produce polyglutamine tracts that cause neurodegenerative diseases. The best known example is Huntington’s disease, along with various spinocerebellar ataxias. The clinical impact typically correlates with repeat length, with longer repeats associated with earlier onset and more severe disease. Normal alleles have a smaller number of repeats, while pathogenic expansions exceed the normal range and may show anticipation, where disease worsens in successive generations.

In government and public administration, CAG stands for Comptroller and Auditor General, the title of the officer responsible for auditing government accounts and reporting to the legislature. The precise powers and appointment processes vary by country, but the office generally oversees audits of public sector entities and reports findings to parliament or equivalent bodies.

In medicine, specifically oncology, CAG refers to a chemotherapy regimen that combines cyclophosphamide (C), doxorubicin (A, Adriamycin), and gemcitabine (G). Variants of the regimen are used for certain cancers and are selected based on tumor type, patient condition, and local practice.