Maternal and Paternal Lineages of the Samaritan Isolate: Mutation Rates and Time to Most Recent Common Male Ancestor

• Published in: Annals of human genetics Vol. 67; no. 2; pp. 153 - 164
• Main Authors: Bonné‐Tamir, B., Korostishevsky, M., Redd, A. J., Pel‐Or, Y., Kaplan, M. E., Hammer, M. F.
• Format: Journal Article
• Language: English
• Published: 9600 Garsington Road , Oxford OX4 2DQ , UK , tel +44 1865 776868 , fax +44 1865 714591 Blackwell Science Ltd 01.03.2003; Cambridge University Press
• Subjects: Biological and medical sciences; Biological Evolution; Chromosomes, Human, Y - genetics; DNA, Mitochondrial; Fathers; Female; Fundamental and applied biological sciences. Psychology; Genetics of eukaryotes. Biological and molecular evolution; Haploidy; Haplotypes; Human; Humans; Male; Models, Theoretical; Mothers; Mutation; Phylogeny; Point Mutation; Polymerase Chain Reaction; Polymorphism, Genetic; Polymorphism, Single-Stranded Conformational; Population genetics, reproduction patterns; Time Factors; Human; Paternal origin; Maternal origin; Family study; Inbreeding; Mitochondrial DNA; Y-Chromosome; Mutation; Population genetics; Haplotype
• ISSN: 0003-4800; 1469-1809
• DOI: 10.1046/j.1469-1809.2003.00024.x

Summary The Samaritan community is a small, isolated, and highly endogamous group numbering some 650 members who have maintained extensive genealogical records for the past 13–15 generations. We performed mutation detection experiments on mitochondrial DNAs and Y chromosomes from confirmed maternal and paternal lineages to estimate mutation rates in these two haploid compartments of the genome. One hundred and twenty four DNA samples from different pedigrees (representing 200 generation links) were analyzed for the mtDNA hypervariable I and II regions, and 74 male samples (comprising 139 links) were typed for 12 Y‐STRs mapping to the non‐recombining portion of the Y chromosome (NRY). Excluding two somatic heteroplasmic substitutions and several length variants in the homopolymeric C run in the HVII region, no mutations were found in the Samaritans' maternal lineages. Based on mutations found in Samaritan paternal lineages, an estimate of a mutation rate of 0.42% (95% confidence interval of 0.22%–0.71%) across 12 Y‐STRs was obtained. This estimate is slightly higher than those obtained in previous pedigree studies in other populations. The haplotypes identified in Samaritan paternal lineages that belong to the same haplogroup were used to estimate the number of generations elapsed since their most recent common ancestor (MRCA). The estimate of 80 generations corresponds with accepted traditions of the origin of this sect.