What is the way forward for hepatitis C virus genotypes?

Soon after the discovery of the hepatitis C virus (HCV) by the research gro up at Chiron Corporation in 1989 [1], HCV isolates were identified in Japan and these had a considerable sequence divergence from the HCV prototype re ported from the United States. Since then, many HCV isolates have been repo rted from all over the world and attempts have been made to classify them b y sequence divergence either of the entire genome or subgenomic areas in di fferent genes and in regions of the genome. Initially, only a few HCV genotypes were reported and they attracted consid erable interest in various fields of medicine, with regard to the biologica l relevance on the life cycle of HCV itself as well as their clinical signi ficance in the care of patients with chronic hepatitis C. HCV has been esti mated to infect around 1% of people around the world with predictable and d isturbing sequelae. With the enduring efforts of biologists and clinicians in many countries, an increasing number of HCV isolates have been reported which differ in their genomic sequences, and many naming systems have been proposed to define and classify HCV genotypes. As increasing varieties of HCV are added to the list, few of which appear t o be of clinical relevance, HCV genotypes are rapidly losing their initial impact. II would appear that interest in HCV genotypes is going to be confi ned to a very narrow field of virology, where only a handful of genotypists endeavour to classify them into infinitely diverse categories, and discuss the identity of newly reported genotypes. Such an intricate classification , impressive as it is, can scare away scientists and doctors working in the ether fields; most of them will find it difficult to catch up with ever ex panding varieties of this RNA virus. The time may come when we start to consider the future of HCV genotypes and contemplate how to deal with them sensibly without losing the attention of biologists and physicians at large. The purpose of this mini-review is to focus on some controversial issues surrounding HCV genotyping nowadays, in the hope for finding a way Forward into the future. For extended overviews and historical perspectives, articles from research groups concerned in HCV genotypes will be referred to [2-7]. Updates on increasing varieties of HC V genotypes may be found in their most recent reports [8-10].