Eight subependymal giant cell astrocytomas (SEGA) were studied by comparative genomic hybridisation. These consisted of six primary SEGA and two recurrences gained from six paediatric patients suffering from tuberous sclerosis complex (TSC). No DNA copy number changes were found in any of the tumours. Our data show that chromosomal imbalances are absent or very rare events in primary and recurrent SEGA and that no aberrations were detected at the sites of the TSC-associated genes, thus indicating that mutational inactivation of one of the TSC genes is not followed by genomic instability.