title: D9S1120, a simple STR with a common Native American-specific allele: forensic optimization, locus characterization and allele frequency studies.
abstract: The simple tetrameric STR D9S1120 exhibits a common population-specific allele of 9 repeats (9RA) reported to have an average frequency of 0.36 in Native Americans from both North and South of the continent. Apart from the presence of 9RA in two northeast Siberian populations, D9S1120 shows variability exclusive to, and universal in all American populations studied to date. This STR therefore provides an informative forensic marker applicable in countries with significant proportions of Native American populations or ancestry. We have re-designed PCR primers that reduce the amplified product sizes reported in NCBI UniSTS by more than a third and have characterized the repeat structure of D9S1120. The 9RA allele shares the same repeat structure as the majority of other D9S1120 alleles and so originates from a slippage-diminution mutation rather than an independent deletion. We confirm the previously reported allele frequencies from a range of populations indicating a global heterozygosity range for D9S1120 of 66-75% and estimate the proportion of Native American-diagnostic genotypes to average 53%, underlining the potential usefulness of this STR in both forensic identification and in population genetics studies of the Americas.
authors.affiliation: Genomic Medicine Group, CIBERER, University of Santiago de Compostela, Galicia, Spain. c.phillips@mac.com
authors.forename: C
authors.initials: C
authors.lastname: Phillips
authors.forename: A
authors.initials: A
authors.lastname: Rodriguez
authors.forename: A
authors.initials: A
authors.lastname: Mosquera-Miguel
authors.forename: M
authors.initials: M
authors.lastname: Fondevila
authors.forename: L
authors.initials: L
authors.lastname: Porras-Hurtado
authors.forename: F
authors.initials: F
authors.lastname: Rondon
authors.forename: A
authors.initials: A
authors.lastname: Salas
authors.forename: A
authors.initials: A
authors.lastname: Carracedo
authors.forename: M V
authors.initials: MV
authors.lastname: Lareu
mesh_terms: D001483:Base Sequence; D017931:DNA Primers; D053803:Forensic Genetics / Q000379:methods*; D005787:Gene Frequency / Q000235:genetics; D006801:Humans; D007198:Indians, North American / Q000235:genetics*; D008969:Molecular Sequence Data; D009656:North America; D020641:Polymorphism, Single Nucleotide; D012800:Siberia; D013020:South America; D020080:Tandem Repeat Sequences / Q000235:genetics*
chemical_list: D017931:DNA Primers