Spondyloepiphyseal dysplasia, corneal clouding, normal intelligence and acid β‐galactosidase deficiency

Abstract

A 14‐year‐old girl with a unique type of progressive spondyloepiphyseal dysplasia, corneal clouding, and no evidence of neurological abnormality, was found to have a remarkable deficiency of acid β‐galactosidase activity in cultured skin fibroblasts and in leucocyte preparations. In fibroblasts, ganglioside GM₁β‐galactosidase activity averaged 7 % of the normal mean while asialofetuin β‐galactosidase and 4‐methylumbelliferyl‐β‐galactosidase averaged 1.4 % and 3.5 %, respectively. Activities for all three substrates in leucocytes from both her parents were close to 50 % of the normal mean indicating that the patient is homozygous for a mutation (or mutations) affecting GM₁β‐galactosidase.