Applying two methods for linkage disequilibrium analysis to haplotype data spanning six 19q12-q13.1 polymorphic markers, and relying on the physical distances between the markers and the recently mapped SLC7A9 (CSNU3) locus, the age of the founder missense V170M mutation causing non-type I cystinuria in Jews of Libyan ancestry is calculated to be approximately 14 to 15 generations (g) (95% confidence interval: 9-20 g) or slightly more.