| Description |
Gaucher disease (GD) is an autosomal recessive disorder caused by deficiency of the lysosomal hydrolase glucocerebrosidase (GBA) (EC 3.2.1.45), required for the degradation of glycosphingolipids. In Gaucher disease, as a result of GBA deficiency, the body is unable to breakdown glucocerebroside, thus allowing the accumulation of glucosylceramide and glucosphingosine within the lysosomal cells. The clinical presentation of GD consists in a multisystem disorder, and its classification of GD into its three subtypes is dependent primarily on the presence or absence of neurological features. Gaucher disease type 1 is the most common inherited genetic disease affecting Ashkenazi Jews, with a frequency of approximately 1 in 850 individuals having Gaucher disease and 1 in 18 individuals being carriers. Once Gaucher disease is suspected based on clinical presentation, the first line of testing is measuring the glucocerebrosidase (GBA) enzyme activity. The GBA enzymatic assay has been developed as a part of this study by modifying the conditions described by Urban et al (2008). The process of validation was divided into individual steps identified to provide the most optimum conditions for the implementation of this assay. This assay uses the fluorometric methodology to measure the level of enzymatic activity. The fluorometric signal is directly proportional to the concentration of GBA activity in the individual being assessed. iv The evaluation of all components of the method validation included accuracy, precision, linearity, sample requirements, sample stability, and establishment of reference ranges. After the individual assessment of these components, it was concluded that the assay was successfully validated for the measurement of GBA activity, and it provides a valuable tool as the first line of testing for the diagnosis of Gaucher disease. |
