Complementation studies with clinical and biochemical characterizations of a new variant of multiple sulphatase deficiency

Abstract

A patient with a new variant of multiple sulphatase deficiency (MSDv) is reported. Unlike the usual type, onset was late and progress was slow. The phenotypic changes were those usually seen in multiple sulphatase deficiency but much milder. Cytoplasmic accumulations were found in skin fibroblasts, and urinary mucopolysaccharides and sulphatides were high. Arylsulphatases A, B and C (ASA, B and C), heparan N-sulphatase sulphoiduronate sulphatase, and N-acetylgalactosamine 6-sulphatase all had low activity in lymphocytes and cultured skin fibroblasts. Complementation for ASA activity was found in hybrids between MSDv and metachromatic leukodystrophy (MLD) as well as between multiple sulphatase deficiency (MSD) and MLD. Complementation for ASC activity was also seen in hybrids between MSDv and X-linked ichthyosis (XLI), and between MSD and XLI. However, neither ASA nor ASC activity increased in hybrid cells of MSDv and MSD. These results suggested that the mutations of MSDv and of MSD were allelic, although of different phenotypes.

Unusual Clinical Presentation in Two Cases of Multiple Sulfatase Deficiency

“…Onset of symptoms in early infancy is associated with poor chances of survival (13,14). Conversely, when features of the disease appear in late infancy, patients survive longer (15). Our patients had a clinical onset in late infancy, with unusually slow progression of the disease.…”

Fluorescence in situ hybridization analysis is useful for the diagnosis of the carrier state of X‐linked ichthyosis

“…No other family members exhibited ichthyosis. The ASC activities of the proband and the mother in the microsomal fraction of peripheral lymphocytes were assayed using 4‐methylumbelliferyl‐sulfate (4MU‐sulfate) as the substrate, by the method described previously 2 . The ASC activity in the patient was very low (0.346 nmol/mg/h), confirming the diagnosis of XLI.…”