Concurrent diagnoses of Tuberous sclerosis and multiple sclerosis

Tuberous sclerosis (TS) is a monogenic disorder which causes disabling neurological symptoms. Similarly, multiple sclerosis (MS) may result in disability, but in contrast, is diagnosed without genetic testing. Clinicians are advised to exercise caution in diagnosing MS in the presence of a pre-existing genetic disorder, as it may be a potential 'red flag'. A dual diagnosis of MS and TS has not previously been reported in the literature. We provide two cases of known cases of TS who presented with new neurological symptoms and associated physical signs compatible with a dual diagnosis of TS/MS.