New contribution on the LRRK2 G2019S mutation associated to Parkinsonʹs disease: age estimation of a common founder event of old age in Moroccan Berbers

Background: The LRRK2 G2019S mutation is an important genetic determinant of Parkinsonʹs disease (PD) across the world that occurs at an elevated frequency in North Africa. Aim: To estimate the date of the G2019S mutation in Berbers. Material and Methods: We determined the LRRK2 haplotypes in twenty-two G2019S carriers, mostly North Africans, and in one hundred twenty-four Arab, Moroccan Berber and Sephardi Jew controls, using seven microsatellite and two SNP genetic markers. Results: A single haplotype was detected, with some variations, in all mutation carriers. Using a maximum-likelihood method, we estimate that Moroccan Berbers with G2019S share a common ancestor who lived ~128 (95% CI 107-180) generations ago. Conclusion: Our conclusion is that the G2019S mutation of the LRRK2 gene originates 3,840 (95% CI 3,210-5,400) years ago in parkinsonian Moroccan Berbers patients.