Yates et al. (1988) studied 2 brothers with microcephaly who developed malignancies in early childhood. The first died at 15 months with 2 primary tumors: embryonal rhabdomyosarcoma of the ear and retroperitoneal ganglioneuroblastoma. The second, investigated for hypotonia ... Yates et al. (1988) studied 2 brothers with microcephaly who developed malignancies in early childhood. The first died at 15 months with 2 primary tumors: embryonal rhabdomyosarcoma of the ear and retroperitoneal ganglioneuroblastoma. The second, investigated for hypotonia and developmental delay, showed chromosome instability and greatly elevated serum AFP (104150); at 12 months, nephrectomy was performed for nephroblastoma. Profound neutropenia signaled abnormal sensitivity to chemotherapy. Cultured lymphocytes showed a marked excess of chromatid gaps and breaks after X-irradiation, whereas fibroblasts showed normal radiosensitivity. Similar studies in the parents were normal.