alpha-L-iduronidase deficiency and possible Hurler-Scheie genetic compound. Clinical, pathologic, and biochemical findings.

The enzymatic delineation of the mucopolysaccharidoses has revealed that certain syndromes, although phenotypically distinct, share the same enzymatic defect. Patients with the classic Hurler and Scheie syndromes or other phenotypic variations of these two disorders have a deficiency of alpha-L-iduronidase. We are reporting a patient with alpha-L-iduronidase deficiency whose phenotypic abnormalities did not resemble either the Hurler or Scheie syndrome and who may have had either the Hurler-Scheie genetic compound described by McKusick or an allelic disorder. Our patient was a 25-year-old woman whose initial presentation was due to acute paranoia and who was subsequently found to have many morphologic, neurologic, radiographic, and neuropathologic findings consistent with a mucopolysaccharide disorder. To our knowledge, complete neuropathologic findings have not been previously described in this hybrid group of patients. A distinctive feature of this patient's illness is that the underlying disorder was not clinically apparent until adulthood, but presented with sever bony abnormalities of the skull and deposition of mucopolysaccharides in the meninges.