Saturnina C Halos

University of the Philippines Diliman, Diliman, Central Luzon, Philippines

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Publications (8)18.7 Total impact

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    ABSTRACT: The Philippines exhibits a rich diversity of people, languages, and culture, including so-called 'Negrito' groups that have for long fascinated anthropologists, yet little is known about their genetic diversity. We report here, a survey of Y-chromosome variation in 390 individuals from 16 Filipino ethnolinguistic groups, including six Negrito groups, from across the archipelago. We find extreme diversity in the Y-chromosome lineages of Filipino groups with heterogeneity seen in both Negrito and non-Negrito groups, which does not support a simple dichotomy of Filipino groups as Negrito vs non-Negrito. Filipino non-recombining region of the human Y chromosome lineages reflect a chronology that extends from after the initial colonization of the Asia-Pacific region, to the time frame of the Austronesian expansion. Filipino groups appear to have diverse genetic affinities with different populations in the Asia-Pacific region. In particular, some Negrito groups are associated with indigenous Australians, with a potential time for the association ranging from the initial colonization of the region to more recent (after colonization) times. Overall, our results indicate extensive heterogeneity contributing to a complex genetic history for Filipino groups, with varying roles for migrations from outside the Philippines, genetic drift, and admixture among neighboring groups.
    European journal of human genetics: EJHG 09/2010; 19(2):224-30. · 3.56 Impact Factor
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    Jasmin Jiji Miranda, Saturnina C Halos
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    ABSTRACT: Population data was collected for the STR loci F13AO1, FES/FPS, HUMvWA, and HUMTHO1, in three major Philippine ethnolinguistic groups and used to estimate statistical parameters for identity testing in forensic work on Filipinos. The Cebuano, Ilocano, and Pampango populations in the Philippines were studied because they are among the biggest linguistic groups in the country, thus their genotypic profiles should substantially represent those of many Filipinos. The number of alleles varied from 4 to 9 at all loci, falling within the range observed for other local and world populations. Pairwise comparisons of the allele frequency distributions showed no statistical differences among the populations. The test for linkage equilibrium showed no evidence of non-random association of alleles across the physically unlinked loci in any of the three populations. The four loci combined gave an exclusion power of > or =0.9995 and a power of paternity exclusion of 0.8859-0.9389.
    Journal of applied genetics 02/2004; 45(1):87-93. · 1.85 Impact Factor
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    Journal of Forensic Sciences 12/2002; 47(6):1397-8. · 1.24 Impact Factor
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    ABSTRACT: In 5 percent of paternity determination cases, only DNA samples from the alleged father and child pairs are tested. The absence of the mother's DNA increases the probability of false paternity inclusions, which affects laboratories that use a limited number of DNA markers. The effect of coincidental matches between unrelated individuals on DNA tests of motherless cases was determined using the Philippine population genetic database of the National Capital Region (NCR). Seven short tandem repeat (STR) markers were used, namely HUMvWA, HUMTH01, HUMCSF1PO, HUMFOLP23, D8S306, HUMFES/FPS, and HUMF13A01. Values of the probability of paternity with (W) and without a mother (W(-mother)) were determined using the equation W = cumulative likelihood ratio/cumulative likelihood ratio + 1). These values were determined for 50 volunteer families and compared with values calculated from randomly matched pairs in a reference NCR population database. The W and W(-mother) values of the 50 families range from 96.48 to 99.99 percent and 79.76 to 99.99 percent, respectively. In the NCR database, 195 coincidental matches in seven STR loci out of 5253 possible pairs (3.71%) were detected with W(-mother) values ranging from 12.47 to 99.83 percent. Of these, 53 and 10 random pairs have W(-mother) greater than 95.0 and 99.0 percent, respectively. W was higher than W(-mother) in the 50 families. However, the existence of unrelated individuals in the NCR database that randomly matched at seven STR loci and that has W(-mother) values greater than 99.0 percent highlights the need for greater precaution when dealing with motherless cases.
    Transfusion 08/2002; 42(7):954-7. · 3.53 Impact Factor
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    ABSTRACT: BACKGROUND: In 5 percent of paternity determination cases, only DNA samples from the alleged father and child pairs are tested. The absence of the mother's DNA increases the probability of false paternity inclusions, which affects laboratories that use a limited number of DNA markers. The effect of coincidental matches between unrelated individuals on DNA tests of motherless cases was determined using the Philippine population genetic database of the National Capital Region (NCR).STUDY DESIGN AND METHODS: Seven short tandem repeat (STR) markers were used, namely HUMvWA, HUMTH01, HUMCSF1PO, HUMFOLP23, D8S306, HUMFES/FPS, and HUMF13A01. Values of the probability of paternity with (W) and without a mother (W-mother) were determined using the equation W = cumulative likelihood ratio/cumulative likelihood ratio + 1). These values were determined for 50 volunteer families and compared with values calculated from randomly matched pairs in a reference NCR population database.RESULTS: The W and W-mother values of the 50 families range from 96.48 to 99.99 percent and 79.76 to 99.99 percent, respectively. In the NCR database, 195 coincidental matches in seven STR loci out of 5253 possible pairs (3.71%) were detected with W-mother values ranging from 12.47 to 99.83 percent. Of these, 53 and 10 random pairs have W-mother greater than 95.0 and 99.0 percent, respectively.CONCLUSION: W was higher than W-mother in the 50 families. However, the existence of unrelated individuals in the NCR database that randomly matched at seven STR loci and that has W-mother values greater than 99.0 percent highlights the need for greater precaution when dealing with motherless cases.
    Transfusion 06/2002; 42(7):954 - 957. · 3.53 Impact Factor
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    ABSTRACT: Allele frequency distributions for a Filipino population from the National Capital Region (NCR) were determined for eight STR loci: HUMF13A01, HUMFES/FPS, HUMvWA, HUMFOLP23, HUMD8S306, HUMCSFIPO, HUMTPOX and HUMTHO1; and a VNTR locus: D1S80. Statistical analysis showed that the nine loci showed no deviations from Hardy-Weinberg and linkage equilibrium rules. The average power of paternity exclusion for the nine loci is 0.9962 and the discriminating power is 1-2 x 10(-9). The data obtained from this study will be used as reference data for forensic DNA typing in the Philippines.
    Forensic Science International 05/1999; 101(1):27-32. · 2.31 Impact Factor
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    ABSTRACT: Allele frequency distributions at the short tandem repeat (STR) loci HUMVWA, HUMFES, HUMF13A01 and of the variable number of tandem repeat (VNTR) locus D1S80 were determined in a Filipino population from Metro Manila (103 individuals) by use of the polymerase chain reaction (PCR) followed by polyacrylamide gel electrophoresis (PAGE). The exact test demonstrated that all four loci had no deviations from Hardy-Weinberg equilibrium (HWE) with the only reservation that the exact test p-value for F13A01 is weak. The discriminating power is 0.82 for D1S80, and the expected exclusion chance is 0.85 for F13A01, 0.83 for FES, and 0.93 for VWA. The observed heterozygosity rates are 0.63 for D1S80, 0.66 for F13A01, 0.67 for FES, and 0.80 for VWA. The exact test for independance between all loci gave a p-value of 0.0195. This is the first time that Filipino population data of DNA loci of forensic importance are reported.
    Deutsche Zeitschrift für die Gesamte Gerichtliche Medizin 02/1998; 111(4):224-6. · 2.69 Impact Factor
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    ABSTRACT: One type of crime scene evidence commonly submitted for analysis is bloodstain on denim. However, chemicals (e.g., indigo) used to produce denim materials may co-purify with DNA and hence, affect subsequent DNA analysis. The present study compared five methods (e.g., standard organic, organic with hydrogen peroxide (H 2 O 2), modified FTA™, organic/Chelex®-Centricon®, and QIAamp® DNA Mini Kit-based procedures) for the isolation of blood DNA from denim. A Short Tandem Repeat (STR)-based analysis across two to nine STR markers, namely, HUMvWA, HUMTH01, D8S306, HUMFES/FPS, HUMDHFRP2, HUMF13A01, HUMFGA, HUMTPOX, and HUMCSF1PO, was used to evaluate successful amplification of blood DNA extracted from light indigo, dark indigo, indigo-sulfur, pure indigo, sulfur-top, and sulfur-bottom denim materials. The results of the present study support the utility of organic/ Chelex®-Centricon® and QIAamp® Kit procedures in extracting PCR-amplifiable DNA from five different types of denim materials for STR analysis. Furthermore, a solid-based method using FTA™ classic cards was modified to provide a simple, rapid, safe, and cost-effective procedure for extracting blood DNA from light, dark indigo and pure indigo denim materials. However, DNA eluted from bloodstained sulfur-dyed denims (e.g., sulfur-top and sulfur-bottom) using FTA™ procedure was not readily amplifiable.