Complete genome of a JC virus genotype type 6 from the brain of an African American with progressive multifocal leukoencephalopathy.

OBJECTIVES

The major genotypes of the human polyomavirus JC (JCV) include type 1 (European), type 2 (Asian), type 3 (African), and type 4 (United States). Here we report characterization of the complete genome of a genotype obtained from the brain of an African American with systemic lupus erythematosus (SLE) and progressive multifocal leukoencephalopathy (PML).

STUDY DESIGN/

METHODS

DNA extracted from JCV-infected brain tissue was subjected to whole-genome polymerase chain reaction (PCR) amplification and direct cycle sequencing. Relations to other JCV genotypes and the predicted amino acid sequence were analyzed.

RESULTS

This African-American type 6 strain (#601) differs from strains of all other genotypes in about 2% of its DNA sequence. The length of the total coding region of strain #601 is increased to 4855 bp by the insertion of a single nucleotide in the large T-antigen intron. This strain, originally placed with the type 2 group on the basis of its sequence in the VT-intergenic region, is very closely related to strains recently identified in the urine of individuals from Ghana, West Africa.

CONCLUSIONS

This is the first example of an African JCV genotype identified in the brain of an African-American PML patient. The extent of sequence divergence of JCV type 6 suggests a split of type 6 strains before the separation of types 2 and 3. These findings confirm that distinctive African genotypes of JCV have been maintained in the African-American population and that they are capable of causing PML.