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1.
Forensic Sci Int Genet ; 29: 80-99, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28391141

RESUMEN

We report here a novel multiplexed DNA analysis system consisting of 20 Alu markers and Amelogenin for analysis of highly degraded forensic biological samples. The key to the success of the system in obtaining results from degraded samples is the primer design yielding small amplicon size (60-125bp) for all 20 markers. The markers included in the InnoTyper® 21 system are bi-allelic, having two possible allelic states (insertion or null) and thus termed INNULs. The markers are short interspersed nuclear elements (SINEs), a category of retrotransposable elements (REs) which are non-coding genomic DNA repeat sequences, or "mobile insertion elements," comprising approximately 40% of the human genome. Alu elements are primate specific SINEs that have reached a copy number in excess of one million in the human genome, which makes these markers highly sensitive and desirable for forensic samples with extremely degraded DNA. Until now however, due to the inherent size difference associated with insertion and no insertion alleles, the use of Alu REs has not been practical for forensic applications. The novel primer design described herein has allowed the development of a multiplexed Alu system yielding fragment sizes amenable to degraded DNA samples, as frequently encountered in missing persons cases or forensic samples such as hair shafts. Although use of Alus in human identity has been studied using single marker amplification and reported before, we report for the first time development and validation of a system with multiplexed RE markers. Studies performed include PCR optimization, species specificity, sensitivity, degradation and inhibition, precision and accuracy, nonprobative samples, mixture, and population database studies. A population study using 592 samples including five populations was performed using InnoTyper 21. The data indicated the random match probability for the combination of these 20 Alu markers was greater than 1 in 3.8 million for the populations studied, indicating the greater statistical power of these autosomal nuclear DNA markers over haplotype systems typically used in such degraded samples. Results demonstrate the system is successful in obtaining results from highly degraded DNA. A sensitivity study performed demonstrated at least 95% recovery of alleles from as low as 50pg of total input DNA, and partial profiles from as low as 25pg. This study has demonstrated that the bi-allelic INNULs in the InnoTyper 21 system provide a sensitivity of detection and a power of discrimination that makes them useful for human identification of extremely degraded samples.


Asunto(s)
Dermatoglifia del ADN/instrumentación , Alelos , Elementos Alu/genética , Amelogenina/genética , Animales , Degradación Necrótica del ADN , Electroforesis Capilar , Marcadores Genéticos , Variación Genética , Humanos , Reacción en Cadena de la Polimerasa , Grupos Raciales/genética , Especificidad de la Especie
2.
Forensic Sci Int Genet ; 13: 224-35, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25212510

RESUMEN

There is a constant need in forensic casework laboratories for an improved way to increase the first-pass success rate of forensic samples. The recent advances in mini STR analysis, SNP, and Alu marker systems have now made it possible to analyze highly compromised samples, yet few tools are available that can simultaneously provide an assessment of quantity, inhibition, and degradation in a sample prior to genotyping. Currently there are several different approaches used for fluorescence-based quantification assays which provide a measure of quantity and inhibition. However, a system which can also assess the extent of degradation in a forensic sample will be a useful tool for DNA analysts. Possessing this information prior to genotyping will allow an analyst to more informatively make downstream decisions for the successful typing of a forensic sample without unnecessarily consuming DNA extract. Real-time PCR provides a reliable method for determining the amount and quality of amplifiable DNA in a biological sample. Alu are Short Interspersed Elements (SINE), approximately 300bp insertions which are distributed throughout the human genome in large copy number. The use of an internal primer to amplify a segment of an Alu element allows for human specificity as well as high sensitivity when compared to a single copy target. The advantage of an Alu system is the presence of a large number (>1000) of fixed insertions in every human genome, which minimizes the individual specific variation possible when using a multi-copy target quantification system. This study utilizes two independent retrotransposon genomic targets to obtain quantification of an 80bp "short" DNA fragment and a 207bp "long" DNA fragment in a degraded DNA sample in the multiplex system InnoQuant™. The ratio of the two quantitation values provides a "Degradation Index", or a qualitative measure of a sample's extent of degradation. The Degradation Index was found to be predictive of the observed loss of STR markers and alleles as degradation increases. Use of a synthetic target as an internal positive control (IPC) provides an additional assessment for the presence of PCR inhibitors in the test sample. In conclusion, a DNA based qualitative/quantitative/inhibition assessment system that accurately predicts the status of a biological sample, will be a valuable tool for deciding which DNA test kit to utilize and how much target DNA to use, when processing compromised forensic samples for DNA testing.


Asunto(s)
Elementos Alu/genética , Degradación Necrótica del ADN , ADN/análisis , Retroelementos/genética , Animales , Humanos , Repeticiones de Microsatélite , Reacción en Cadena de la Polimerasa Multiplex , Reacción en Cadena en Tiempo Real de la Polimerasa , Reproducibilidad de los Resultados , Especificidad de la Especie , Temperatura de Transición
3.
Issue Brief (Commonw Fund) ; 2: 1-20, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24719969

RESUMEN

Caring for the 9 million low-income elderly or disabled adults who are eligible for full benefits under both Medicare and Medicaid can be extremely costly. As part of the federal Financial Alignment Initiative, states have the opportunity to test care models for dual-eligibles that integrate acute care, behavioral health and mental health services, and long-term services and supports, with the goals of enhancing access to services, improving care quality, containing costs, and reducing administrative barriers. One of the challenges in designing these demonstrations is choosing and applying measures that accurately track changes in quality over time­essential for the rapid identification of effective innovations. This brief reviews the quality measures chosen by eight demonstration states as of December 2013. The authors find that while some quality domains are well represented, others are not. Quality-of-life measures are notably lacking, as are informative, standardized measures of long-term services and supports.


Asunto(s)
Prestación Integrada de Atención de Salud/organización & administración , Doble Elegibilidad para MEDICAID y MEDICARE , Programas Controlados de Atención en Salud/organización & administración , Indicadores de Calidad de la Atención de Salud , Adulto , Anciano , Anciano de 80 o más Años , Capitación/organización & administración , Planes de Aranceles por Servicios/organización & administración , Humanos , Cuidados a Largo Plazo , Persona de Mediana Edad , Proyectos Piloto , Calidad de Vida , Gobierno Estatal , Estados Unidos
4.
Hum Hered ; 74(1): 27-35, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23095285

RESUMEN

OBJECTIVES: Retrotransposable elements (REs), consisting of long interspersed nuclear elements (LINEs) and short interspersed nuclear elements (SINEs), are a group of markers that can be useful for human identity testing. Until now, however, due to the inherent size difference (up to 6 kb in some instances) associated with insertion and null alleles (or INNULs), the use of REs for facilitated population studies has not been sought or practical. The size of the insertion elements (from a few hundred to several thousand bp) has proven to limit their utility as a marker because of the inefficient amplicon yield with PCR. A novel primer design now facilitates INNUL marker testing. A preliminary panel of single-locus markers was developed to evaluate the potential of typing these insertion elements. Nine INNULs (5 Alu and 4 LINEs) were typed in three major North American populations and analyzed for population genetic features. In addition, the variation of each marker among the sample populations provides insight of its potential use as individual identification or ancestral marker. METHODS: INNUL markers were developed into fluorescently labeled single-loci PCR. Nine markers were developed with amplicons that were less than 180 bp in length, and, depending on the locus amplicons of the INNULs, alleles varied in size from 50 to 1 bp. This allele size is noteworthy because the insertion alleles of the 9 loci range in size from 297 to 6,195 bp. The allele distribution of the INNULs was assessed and analyzed in three major North American populations. RESULTS: Upon observation of the distribution of the alleles in three major North American populations, the markers generally met Hardy-Weinberg expectations, and there was little evidence of detectable levels of linkage disequilibrium. Due to varying distributions of the alleles in the major population groups tested, some of the markers might be better suited for use as an individual identification marker, while others are better suited for bio-ancestral studies. CONCLUSIONS: Using the primer design strategy described in our work, SINEs and (for the first time, to our knowledge) LINEs can be utilized as markers for studying population genetic variation that is more amenable to the limitations of the PCR technique. This study lays the foundation for future work of developing a multiplex panel of INNUL markers that can be used as a single-tube assay for human identity testing utilizing small amplicons (<180 bp), which could be useful for ancient or degraded forensic DNA samples.


Asunto(s)
Variación Genética , Genética de Población/métodos , Retroelementos , Programas Informáticos , Alelos , Cartilla de ADN/genética , Humanos , Reacción en Cadena de la Polimerasa , Polimorfismo Genético , Grupos Raciales/genética
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