Severe intrauterine growth retardation with increased mitomycin C sensitivity: a further chromosome breakage syndrome.

We report an infant with pre- and postnatal microcephaly and growth retardation, a distinctive face, and developmental delay. The initial diagnosis was of Seckel syndrome. He became pancytopenic at 16 months and died soon after. His bone marrow was of normal cellularity but had a small lymphocyte infiltration. Increased spontaneous chromosome breakage was seen in blood and fibroblasts. Mitomycin C induced chromosome damage was increased and comparable to that seen in Fanconi anaemia. Reports of similar patients are reviewed. This entity of severe intrauterine growth retardation and increased mitomycin C sensitivity is hypothesised to be a distinct chromosome breakage syndrome.