Taxonomy of Hepatitis G virus (GB virus C): To which virus family does it belong?

Introduction:
Hepatitis G virus, more accurately known as GB virus C, is not a classic hepatitis virus causing liver disease, yet it clusters phylogenetically with a familiar RNA virus family. Correct classification aids understanding of genome organization and replication.

Given Data / Assumptions:

• We must assign Hepatitis G virus (GBV-C) to the correct family.
• Genome type and polyprotein strategy suggest a specific family.

Concept / Approach:
GBV-C is a positive-sense single-stranded RNA virus grouped within Flaviviridae, historically alongside HCV. It shares the general flaviviral genomic layout: a single ORF translated into a polyprotein processed into structural and nonstructural proteins.

Step-by-Step Solution:
Recall that HCV and GBV-C are positive-sense RNA viruses with similar replication strategies. Map this to the Flaviviridae family. Select Flaviviridae as the correct classification.

Verification / Alternative check:
Molecular phylogeny and genome organization studies consistently place GBV-C within Flaviviridae.

Why Other Options Are Wrong:

• Caliciviridae / Coronaviridae / Paramyxoviridae: Different genome organizations and replication strategies.
• Hepadnaviridae: DNA viruses with reverse transcription, unlike GBV-C RNA genome.

Common Pitfalls:
Assuming the name “Hepatitis G” implies similar biology to HBV; naming is historical and does not reflect family membership.

Final Answer:
Hepatitis G virus belongs to Flaviviridae.