Identical twins with mental retardation, dysarthria, progressive spastic paraplegia, and brachydactyly type E: a new syndrome or variant of Fitzsimmons-Guilbert syndrome?

We report on concordantly affected female identical twins with mental retardation, dysarthria, progressive spastic paraplegia, and brachydactyly type E. The most similar condition reported is the syndrome described by Fitzsimmons and Guilbert in uniovular twins characterized by progressive spastic paraplegia, dysarthria, brachydactyly type E, and cone-shaped epiphyses. During the last 11 years a report of only one other patient with this syndrome has been published; hence, its phenotypic delineation may be only partial. Although our patients might expand the phenotypic spectrum of this syndrome, they may represent a new disorder.