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Updated: Jul 13, 2026

Quantitative Fluorescence In Situ Hybridization (FISH) and Immunofluorescence (IF) of Specific Gene Products in KSHV-Infected Cells
Published on: August 27, 2019
Evaluation of global clustering patterns and strain variation over an extended ORF26 gene locus from Kaposi's sarcoma
Jian-Chao Zong1, Henry Kajumbula, William Boto
1Viral Oncology Program, Department of Oncology, Blunting Blaustein Cancer Research Building, Sydney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, MD 21231-1000, United States.
Background:
Small 233-bp or 330-bp DNA fragments of the ORF26 gene of human Kaposi's sarcoma herpesvirus (KSHV) have been used extensively to identify KSHV by PCR in clinical samples; to associate KSHV with novel diseases and to correlate KSHV strain differences with pathogenicity.
Objectives:
We evaluated the nature, extent and source of nucleotide sequence variability among a large and diverse set of known KSHV-positive DNA samples.
Study Design:
Direct DNA PCR sequencing was carried out on 136 distinct Kaposi's sarcoma and primary effusion lymphoma-related samples from different geographic locations.
Results:
The presence of 26 diagnostic nucleotide polymorphisms across an expanded 965-bp PCR locus define eight distinct ORF26E genotypes, three being of Eurasian origin, one from the Pacific Rim, and five from Sub-Saharan Africa. Previous ambiguities between some genotype patterns in the 330-bp locus data are fully resolved.
Conclusions:
This analysis provides an expanded database for understanding and evaluating ORF26 polymorphisms. In particular, the eight genotype clusters correlated with specific ethnic and geographic origins of the patients. Furthermore, the very low level of additional sporadic nucleotide variation found permits detection of spurious sequence errors or contamination present in some published data.
