Mutation in the sphingolipid activator protein 2 in a patient with a variant of Gaucher disease

Abstract

The lysosomal degradation of glucosylceramide requires the hydrolase, glucosylceramide‐β‐glucosidase and a sphingolipid activator protein (Gaucher factor, SAP‐2, saposin C). Genetic defects in either of these lysosomal proteins cause phenotypically similar disorders in man, the Gaucher disease. SAP‐2 originates from a gene which generates a mRNA that codes for four homologous proteins. In a patient with an immunologically proven SAP‐2 deficiency a G1154 → T transversion (counted from A of the initiation codon ATG) was found in the mRNA of the SAP‐2 precursor which results in the substitution of Phe for Cys385 in the mature SAP‐2. The rest of the coding sequence remained entirely normal.