Gene responsible for mutation of HBV is C gene

Gene responsible for mutation of HBV is
a) X gene
b) S gene
c) P gene
d) C gene
Correct Answer - D
Ans. is- D- i.e., C gene
Two categories of naturally occurring HBV variants have attracted
the most attention.
One of these was identified initially in Mediterranean countries
among patients with an unusual serologic clinical profile. They have
severe chronic HBV infection and detectable HBV DNA but with anti-
HBe instead of HBeAg.
These patients were found to be infected with an HBA mutant that
contained an alteration in the pre-core region rendering the
virus incapable of encoding HBeAg.
Another mutation, in the core-promoter region, prevents
transcription of the coding region for HBeAg and yields an HBeAg‐
negative phenotype.
Patients with such mutations in the pre-core region and who are
unable to secrete HBeAg tend to have severe liver disease that
progresses more rapidly to cirrhosis, or they are identified
clinically later in the course of the natural history of chronic hepatitis
B when the disease is more advanced.
Both “wild-type” HBV and pre-core-mutant HBV can coexist in the
same patient, or mutant HBV may arise late during wild-type HBV