Contributor: Gordon K. Klintworth
Mucopolysaccharidosis type I-H/S (Hurler/Scheie complex, Hurler-Scheie compound, Hurler-Scheie syndrome, OMIM #60715) is one variety of mucopolysaccharidosis. It is caused by a mutation in the IDUA gene that encodes for alpha-L-iduronidase. Affected individuals with this lysosomal storage disease develop a phenotype that is intermediate in severity between the allelic disorders mucopolysaccharidosis type I-H and mucopolysaccharidosis type I-S. Mucopolysaccharidosis type I-H/S occurs when an individual is a compound  heterozygote that inherits one mutant allele for mucopolysaccharidosis type I-H and one for mucopolysaccharidosis type I-S. A clouding of the cornea invariably occurs and several patients have had corneal grafts. Following penetrating keratoplasty the grafts have remained clear for 2-8 years. Corneal specimens obtained from affected individuals have disclosed numerous vacuoles containing a predominance of fibrillogranular and multimembranous materials within corneal epithelium, histiocytes, keratocytes, and corneal endothelium. Aside from corneal opacification visual impairment may be due retinal degeneration. The ERG is sometimes extinguished and a pigmentary retinopathy with "bone spicule" shaped areas of pigmentation resembling retinitis pigmentosa may be present. Papilledema has also been reported. Cornea clouding invariably occurs in mucopolysaccharidosis type I-H/S and several patients have had corneal grafts. Following penetrating keratoplasty the grafts have remained clear for 2, 4 and 8 years. Corneal specimens obtained from two patients with mucopolysaccharidosis type I-H/S have disclosed numerous vacuoles containing a predominance of fibrillogranular and multimembranous materials within corneal epithelial cells, histiocytes, keratocytes and endothelial cells.Aside from corneal opacification visual impairment may be due retinal degeneration. The ERG is sometimes extinguished and a pigmentary retinopathy with "bone spicule" shaped areas of pigmentation resembling retinitis pigmentosa may be present. Papilledema has also been reported.