High incidence of myeloproliferative disorders in Ashkenazi Jews in northern Israel.

We have analysed epidemiological parameters in 339 patients with myeloproliferative disorders (MPD) diagnosed in northern Israel between 1975 and 1989 as having polycythemia vera (191 patients), agnogenic myeloid metaplasia (AMM) (113) and essential thrombocythemia (ET) (36). Mean average annual incidence was 11.4 per 1 million residents for polycythemia vera, 6.5 for AMM and 2.1 for ET. For all three diseases the average annual incidence increased with age and was 10 times higher in patients over 65 years compared to those less under the age of 45 years. Four percent of all patients had relatives with MPD. Incidence of MPD in Jews was 10 fold higher than expected compared to Arabs and this difference was noted for all 3 diseases. The incidence in Ashkenazi Jews originating from eastern and central Europe, was 10 and 20 folds higher than in Sephardic Jews and Arabs respectively. Mean age at diagnosis of MPD in Arabs and Sephardic Jews was lower than in Ashkenazi Jews (52 and 56 years compared to 64 years P < 0.05). Likewise, mean age at diagnosis was lower in the 11.5% of MPD patients with prior exposure to biological or chemical hazards compared to unexposed individuals (58 years versus 63 years, P < 0.02). These data demonstrate a cluster of MPD in Ashkenazi Jews in northern Israel and emphasize the importance of genetic predisposition possibly interacting with acquired factors in the pathogenesis of these disorders.