Clinical, biochemical, and ultrastructural studies in a case of chondrodystrophy presenting the I-cell phenotype in tissue culture

Abstract

A description is given of a boy who presented early and severe clinical and radiological signs of chondrodystrophy without increased mucopolysacchariduria. Liver acid β-galactosidase activity was decreased. Ultrastructural studies disclosed the presence of clear membrane-bound inclusions, particularly numerous in fibrocytes and glomerular epithelial cells. In hepatocytes and neurons only a few pleiomorphic inclusions were present. In skin tissue culture, living cells were filled with dark granules showing an aspect characteristic of the “I-cell” phenotype. Findings that distinguish this clinical pattern from the typical mucopolysaccharidoses are discussed. A description is given of a boy who presented early and severe clinical and radiological signs of chondrodystrophy without increased mucopolysacchariduria. Liver acid β-galactosidase activity was decreased. Ultrastructural studies disclosed the presence of clear membrane-bound inclusions, particularly numerous in fibrocytes and glomerular epithelial cells. In hepatocytes and neurons only a few pleiomorphic inclusions were present. In skin tissue culture, living cells were filled with dark granules showing an aspect characteristic of the “I-cell” phenotype. Findings that distinguish this clinical pattern from the typical mucopolysaccharidoses are discussed.