Biochemical Validation of Skin Fibroblast Culture and Filipin Staining for Diagnosis of Niemann-Pick Type C Disease

Abstract

This study included 199 patients referred to the Department of Biochemistry and Molecular Biology, Faculty of Medicine, Ain Shams University and the Biochemical Genetics Department, National Research Center by the Hematology Clinic, Children Hospital, Ain Shams University. Their ages ranged from 2 months to 15 years. 121 (60.8%) of the 199 patients were males and 78 (39.2%) were females (see figure 3.1A). 144 (70.8%) of these 199 patients were offspring to consanguineous parents and 58 (29.2%) were offspring to non-consanguineous parents. A control group of 20 healthy individuals were selected with matching age and gender. The total number of subjects in this study including the control group was 219. 131 (59.8%) of the 219 were males and 88 (40.2%) were females. 155 (70.8%) of them were offspring to consanguineous parents and 64 (29.2%) were offspring of non-consanguineous parents. There was no statistically significant difference for gender distribution among the different study groups. Consanguinity rate among the study groups showed statistically significant difference. The NPC group showed higher consanguinity rate compared to the other groups studied. Plasma chitotriosodase enzyme activity is a very good screening test for diagnosis of NPC disease. Mean and standard deviation of plasma chitotriosidase enzyme activity were 42.38 µmol.l-1.h-1 ± 15.73 for the non-lysosomal group, 4800 µmol.l-1.h-1 ± 3424 for GD groups, 531 µmol.l-1.h-1 ± 142 for NPC group and 63.82 µmol.l-1.h-1 ± 11.02 for the control group. ROC curves were plotted to estimate the cut-off for suspicion of NPC disease and GD in clinically suspected cases. The cut-off that differentiated the contr