Sphingolipid activator protein 1 deficiency in metachromatic leucodystrophy with normal arylsulphatase A activity. A clinical, morphological, biochemical, and immunological study

Eur J Pediatr. 1991 Jun;150(8):584-91. doi: 10.1007/BF02072213.


A 7-year-old boy had clinical features of metachromatic leucodystrophy (MLD), however, an increased urinary sulphatide excretion was found in the presence of normal arylsulphatase A (and alpha-galactosidase A) activity. A rectal biopsy showed metachromatically staining storage macrophages as well as nonmetachromatic, but PAS-positive, submucosal neurons filled with membranous cytoplasmic bodies. These two types of storage material led to testing for a sphingolipid activator protein (SAP) deficiency. Loading tests with sulphatide and globotriaosylceramide showed deficient turnover of both sphingolipids in cultured fibroblasts. Using the Ouchterlony method, there was no reactivity between a described anti-SAP 1 antiserum and the patient's fibroblast extracts. This new case of SAP-1 deficient MLD was compared with the four cases of this variant known from the literature. Our results indicate that rectal biopsy morphology and lipid loading biochemistry should prove useful for the screening of SAP defects.

Publication types

  • Case Reports

MeSH terms

  • Biopsy
  • Cerebroside-Sulfatase / metabolism*
  • Child
  • Glycoproteins / deficiency*
  • Humans
  • Immunologic Techniques
  • Leukodystrophy, Metachromatic / enzymology
  • Leukodystrophy, Metachromatic / metabolism*
  • Leukodystrophy, Metachromatic / pathology
  • Male
  • Rectum / pathology
  • Saposins
  • Sphingolipid Activator Proteins
  • Sulfoglycosphingolipids / urine


  • Glycoproteins
  • PSAP protein, human
  • Saposins
  • Sphingolipid Activator Proteins
  • Sulfoglycosphingolipids
  • Cerebroside-Sulfatase