[Mosaic variant of the translocation form of syndrome 18q-].

A mosaic form of 18q-syndrome is found, apparently due to de novo translocation at the early stages of embryogenesis. About 60 per cent of cells have disbalanced chromosome set as a result of translocation between chromosomes 13 and 18 and the loss of chromosome regions 13q11 and 18q23, the rest 40 per cent of cells being normal. Clinical features of the proposita are supposed to be conditioned mainly by the loss of the chromosome protein 18q23. Deviations from a classic pattern of the syndrome may be explained by the loss of a proximal part of chromosome 13 and by the mosaic status of abnormality. The case described is considered as a unique translocation and a rare mosaic form of the 18 q-syndrome.