Leukocyte sonicates as a source for both enzyme assay and DNA amplification for mutational analysis of certain lysosomal disorders.

At present the identification of patients and carriers of most lysosomal disorders is accomplished by finding decreased activity of one enzyme in an easily obtained tissue sample such as leukocytes. As the genes for these enzymes are cloned and mutations identified, the use of molecular techniques to supplement enzyme testing will be warranted. To facilitate the implementation of such studies a simple method for isolating DNA from the remaining leukocyte sonicate, and using this DNA for polymerase chain reaction amplification of regions involved in three lysosomal disorders is described. The DNA from the sonicate was isolated without proteinase K digestion, was readily soluble in Tris-EDTA buffer and available for amplification almost immediately. The usefulness of the methods was confirmed by studies on patients and family members with three relatively common lysosomal disorders, metachromatic leukodystrophy. Gaucher disease and Tay-Sachs disease. This method allows immediate DNA analysis without the need for securing an additional blood sample.