TABLE 2.
FIA-MS/MS analysis of the CTGS to tCDCA ratio in DBSs as a test for CTX
| DBS from: | CGTS/tCDCA |
| CTX untreated adults/children (n = 12) | 19.4852 (1.173–41.847) |
| CTX treated adults/children (n = 8) | 3.780 (0.244–20.102) |
| CTX untreated newborns (n = 3, analyzed in duplicate) | 0.814 (0.516–0.962) |
| Identified Druze carrier newborns (n = 9, includes one cholestatic newborn)a | 0.110 (0.028–0.271) |
| Unaffected newborns (1,216 in total; n = 661 Druze, n = 242 Moroccan Jewish, n = 313 general population) | 0.067 (0.007–0.634) |
| Cholestasis newbornsb (25 in total; n = 11 Druze, n = 1 Moroccan Jewish, n = 13 general population) | 0.015 (0.003–0.041) |
Data are expressed as mean (range of results) for m/z 75 product ion. Bold type indicates the 5β-cholestane-25-tetrol-glucuronide/tCDCA ratio values that are provided in Fig. 2A.
Although nine carrier samples overall were identified as part of the MS/MS data analysis (seven prospectively, two previously identified and retrieved from archives), based on the carriership frequency determined for c.355delC CYP27A1 gene variant, we would estimate at least 16 additional unidentified carrier samples to be present in the Druze DBSs biochemically screened.
Around the highest 2% concentration of total bile acid conjugates (determined by semi-quantitative analysis to be >20,000 ng/ml).