The Chuvash form of polycythemia is an autosomal recessive disorder common to a large number of families in central Russia. Affected individuals have been reported to be homozygous for an Arg200Trp mutation in the von Hippel–Lindau (VHL) gene. We have screened 78 patients with erythrocytosis and found 8 of Bangladeshi and Pakistani origin to be homozygous for the Arg200Trp mutation and another of English descent to be heterozygous. Of these patients, 5 have elevated serum erythropoietin (Epo) levels, while the other 4 have Epo values in the normal range. The heterozygous patient does not fulfill the Chuvash criterion for homozygosity of the Arg200Trp mutation and consequently may harbor a further, as yet uncharacterized, mutation. This mutation has a wider geographic distribution than originally presumed and haplotype analysis suggests a common origin of the Arg200Trp mutation in the 4 families, but it still remains to be established if it has arisen independently of the Chuvash population.