The Rett condition--broad clinical variability--a case report over three decades.

A forme fruste Rett variant female with partially preserved speech remnants is described. She was first seen by the author at an age of 4 years. She then presented with an unspecific syndrome of moderate mental retardation. At follow-up when aged 32 she had successively through the years developed a number of Rett characteristic abnormal behavioural patterns and neurologic deviations, together convincingly indicating a Rett syndrome. However, this has been discrete and atypical in original presentation and first apparent in the long term clinical profile. It is underlined that a whole battery of Rett peculiarities appearing with age should be present to allow diagnostic accuracy.