Diploid/tetraploid mosaicism in a liveborn infant demonstrable only in the bone marrow: case report and literature review

A case of a multiply malformed liveborn infant with mosaic tetraploidy on examination of bone marrow but not of peripheral lymphocytes or skin fibroblasts is presented. The literature is reviewed and the clinical features of our patient are compared with those of the nine previously reported cases. We suggest that when the clinical suspicion of polyploidy is strong, it may be prudent to expand the search for the abnormality to include cytogenetic studies of the bone marrow, despite a normal karyotype in peripheral blood.