CHROMOSOMAL BREAKAGE, ENDOMITOSIS, ENDOREDUPLICATION, AND HYPERSENSITIVITY TOWARD RADIOMIMETRIC AND ALKYLATING-AGENTS - A POSSIBLE NEW AUTOSOMAL RECESSIVE MUTATION IN A GIRL WITH CRANIOSYNOSTOSIS AND MICROCEPHALY

A high frequency of spontaneous chromosomal breakage, endomitosis, end oreduplication and hypersensitivity toward both the alkylating agent T renimon and the radiomimetric drug bleomycin was observed in phytohema gglutinin-stimulated peripheral lymphocytes from a girl with craniosyn ostosis, microcephaly, ptosis, bird-like facies, and moderate mental r etardation. We also observed abnormal chromosomal spiralization and so me aspects of abnormal cellular division. Several fruitless attempts w ere made to establish a cell line. The parents were consanguineous, su pporting the existence of a new, rare, autosomal, recessive condition in man. The mutation might involve a gene involved in DNA repair and/o r regulation of the mitotic cycle.