Heterozygous OPA1 mutations in Behr syndrome.

ARTICLE Sir, We read with interest the paper by Yu-Wai-Man et al. (2010) on patients with dominant optic atrophy-plus with OPA1 mutations, which follows on previous reports by the same group (Amati-Bonneau et al. , 2008; Hudson et al. , 2008), reporting the relatively high frequency (∼20%) and the large spectrum of extra-ocular neurological involvement in OPA1 disease. Here, we extend the clinical spectrum of OPA1 mutations to Behr syndrome, characterized by early-onset optic atrophy associated with pyramidal signs, ataxia and sometimes, posterior column sensory loss and mental retardation (Behr 1909; Thomas et al. , 1984). This clinical entity is probably a heterogeneous group of disorders, whose real causes are mostly unknown. In most cases, autosomal recessive inheritance has been suspected. A few patients with typical Behr syndrome and several with Costeff syndrome, a Behr syndrome-like disease associating optic atrophy with extrapyramidal signs, were shown to have type III 3-methylglutaconic aciduria (MGA type III), a recessive disease characterized …