title: Results of the GEP-ISFG collaborative study on two Y-STRs tetraplexes: GEPY I (DYS461, GATA C4, DYS437 and DYS438) and GEPY II (DYS460, GATA A10, GATA H4 and DYS439).
abstract: A collaborative exercise was carried out by the Spanish and Portuguese ISFG Working Group (GEP-ISFG) in order to evaluate the performance of two Y-chromosome STR PCR tetraplexes, which include the loci DYS461, GATA C4, DYS437 and DYS438 (GEPY I), and DYS460, GATA A10, GATA H4 and DYS439 (GEPY II). The participating laboratories were asked to type three samples for the eight markers, using a specific amplification protocol. In addition, two control samples, with known haplotypes, were provided. The results obtained by the 13 different participating laboratories were identical, except for two laboratories that failed to type correctly the same two samples for GATA C4. By sequence analyses, two different GATA C4 allele structures were found. One control sample (allele 21) and two questioned samples (allele 22, correctly typed by all the laboratories, and allele 25) presented the following repeat structure: (TCTA)4(TGTA)2(TCTA)2(TGTA)2(TCTA)n, but different from the one found for allele 26 in one sample included in this exercise, as well as in the second control sample (allele 23), namely (TCTA)4(TGTA)2(TCTA)2(TGTA)2(TCTA)2(TGTA)2(TCTA)n. The collaborative exercise results proved that both Y-tetraplexes produce good amplification results, with the advantage of being efficiently typed using different separation and detection methodologies. However, since GATA C4 repeat presents a complex structure, with alleles differing in sequence structure, efficient denaturing conditions should be followed in order to avoid typing errors due to sizing problems.
authors.affiliation: Institute of Legal Medicine, University of Santiago de Compostela, Compostela, Spain.
authors.forename: Paula
authors.initials: P
authors.lastname: Sánchez-Diz
authors.forename: Leonor
authors.initials: L
authors.lastname: Gusmão
authors.forename: Sandra
authors.initials: S
authors.lastname: Beleza
authors.forename: Alfonso
authors.initials: A
authors.lastname: Benítez-Páez
authors.forename: Azucena
authors.initials: A
authors.lastname: Castro
authors.forename: Oscar
authors.initials: O
authors.lastname: García
authors.forename: Lourdes Prieto
authors.initials: LP
authors.lastname: Solla
authors.forename: Helena
authors.initials: H
authors.lastname: Geada
authors.forename: Pablo
authors.initials: P
authors.lastname: Martín
authors.forename: Begoña
authors.initials: B
authors.lastname: Martínez-Jarreta
authors.forename: Maria
authors.initials: M
authors.lastname: de Fátima Pinheiro
authors.forename: Eduardo
authors.initials: E
authors.lastname: Raimondi
authors.forename: Sandra María
authors.initials: SM
authors.lastname: Silva de la Fuente
authors.forename: Maria Conceição
authors.initials: MC
authors.lastname: Vide
authors.forename: Martin R
authors.initials: MR
authors.lastname: Whittle
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Zarrabeitia
authors.forename: Angel
authors.initials: A
authors.lastname: Carracedo
authors.forename: António
authors.initials: A
authors.lastname: Amorim
mesh_terms: D000483:Alleles; D016022:Case-Control Studies; D041322:Chromosomes, Human, Y; D016172:DNA Fingerprinting / Q000379:methods; D005828:Genetics, Population; D006801:Humans; D008297:Male; D016133:Polymerase Chain Reaction; D011174:Portugal; D013030:Spain; D020080:Tandem Repeat Sequences