FAMILIAL EOSINOPHILIA - CLINICAL AND LABORATORY RESULTS ON A US KINDRED

We describe a five-generation kindred with familial eosinophilia (FE; MIM131400), characterized by the occurrence of sustained eosinophilia of unidentifiable cause in multiple relatives. The inheritance pattern is consistent with an autosomal dominant pattern. Among 52 related su bjects studied, 19 were affected and 33 were unaffected. Ten unaffecte d spouses were also evaluated. Four subjects with sustained eosinophil ia were diagnosed with cardiac abnormalities and two of them also had neurologic symptoms. In comparison with the unaffected or spouses, eva luation of complete blood counts showed that the affected relatives ha d, as expected, significantly higher white cell (P < 0.005) and absolu te eosinophil counts (P < 0.001) and lower red cell counts (P < 0.05). Evaluation of serum cytokine levels (IL-5, IL-3, and granulocyte-macr ophage colony-stimulating factor (GMCSF) and serology for parasitic he lminth infection demonstrated no differences between the affected and unaffected individuals; no individuals studied had serologic evidence for parasitic infection. There were also no differences in anti-nuclea r antibody, serum cobalamin (vitamin B-12) level, immunoglobulin level , leukocyte alkaline phosphatase, rheumatoid factor, HLA analysis, and stool findings for ova and parasites. Among eight affected persons wh o had peripheral blood or bone marrow karyotype analysis, two carried the same chromosome abnormality, a pericentric inversion of chromosome 10, inv (10) (p11.2q21.2). A gene mapping study is currently underway to study the underlying genetic mechanism(s) of this syndrome. (C) 19 98 Wiley-Liss, Inc.