Deficiency of sphingomyelin-cleaving enzyme activity in tissue cultures derived from patients with Niemann-Pick disease

A report of a patient with Niemann-Pick disease type B and a review of the patients in Japan

“…The assay mixture consisted of 50 tA of 0.1~ Triton X-100 and 80 ,ul of homogenate solution (in the case of liver specimens, 20/A of homogenate was mixed with 60 tA of 0.1~ Triton X-100). The following procedures were the same as those described by Sloan et al (1969).…”

“…The type of this disease seen in adult was added as the fifth form by Fredrickson and Sloan (1972). A deficiency in the sphingomyelinase activity is clearly evident in the organs of patients with the disease of type A and B (Sloan et al, 1969). However, enzyme activities in patients with the disease of type C, D and E varied with the reports (Callahan et aI., 1974;Schneider and Kennedy 1967) and enzymatic defects in those patients have not been clarified.…”

Identification and Expression of a Missense Mutation (Y446C) in the Acid Sphingomyelinase Gene from a Japanese Patient with Type A Niemann-Pick Disease.

“…DNA (15 to 20 ,u g) from the construct, as well as the wild-type, full-length pASM-3b, was introduced into COS-1 cells by the method of Chen and Okayama (1987). The transfected cells were harvested after 72 hr and ASM activities were determined using the radioactive substrate, 14C-sphingomyelin as previously described (Sloan et al 1969).…”

High Performance Liquid Chromatography for the Detection of Homozygotes and Heterozygotes of Niemann-Pick Disease

“…The current method for the assay of SPase requires the use of radiolabeled SP (1,15). This material, although now commercially available, is expensive.…”