[Psychotic symptoms during the evolution of dementia in muco- polysaccharidosis of Hurler-Scheie phenotype].

The case reported concerns a 17 1/2 year-old adolescent presenting with complete alpha-L-iduronidase deficiency. Its phenotype intermediate between Hurler's and Scheie's syndromes and the occurrence of a delirious and hallucinatory condition evolving with acute exacerbations on a constant subdelirious and excited state made this case particular. This case report is compared to the 30 in the Anglo-Saxon literature which shows, in addition to the rarity of psychiatric symptoms (one single case), the multiplicity of the possible phenotypes, reinforcing the hypothesis of a polyallelic or even non allelic mutation.