Publications by authors named "Kristiaan J van der Gaag"

28 Publications

  • Page 1 of 1

Application of a probabilistic genotyping software to MPS mixture STR data is supported by similar trends in LRs compared with CE data.

Forensic Sci Int Genet 2021 May 26;52:102489. Epub 2021 Feb 26.

Division of Biological Traces, Netherlands Forensic Institute, The Hague, The Netherlands; University of Amsterdam, Swammerdam Institute for Life Sciences, Amsterdam, The Netherlands. Electronic address:

The interpretation of short tandem repeat (STR) profiles can be challenging when, for example, alleles are masked due to allele sharing among contributors and/or when they are subject to drop-out, for instance from sample degradation. Mixture interpretation can be improved by increasing the number of STRs and/or loci with a higher discriminatory power. Both capillary electrophoresis (CE, 6-dye) and massively parallel sequencing (MPS) provide a platform for analysing relatively large numbers of autosomal STRs. In addition, MPS enables distinguishing between sequence variants, resulting in enlarged discriminatory power. Also, MPS allows for small amplicon sizes for all loci as spacing is not an issue, which is beneficial with degraded DNA. Altogether, MPS has the potential to increase the weights of evidence for true contributors to (complex) DNA profiles. In this study, likelihood ratio (LR) calculations were performed using STR profiles obtained with two different MPS systems and analysed using different settings: 1) MPS PowerSeq™ Auto System profiles analysed using FDSTools equipped with optimized settings such as noise correction, 2) ForenSeq™ DNA Signature Prep Kit profiles analysed using the default settings in the Universal Analysis Software (UAS), and 3) ForenSeq™ DNA Signature Prep Kit profiles analysed using FDSTools empirically adapted to cope with one-directional reads and provisional, basic settings. The LR calculations used genotyping data for two- to four-person mixtures varying for mixture proportion, level of drop-out and allele sharing and were generated with the continuous model EuroForMix. The LR results for the over 2000 sets of propositions were affected by the variation for the number of markers and analysis settings used in the three approaches. Nevertheless, trends for true and non-contributors, effects of replicates, assigned number of contributors, and model validation results were comparable for the three MPS approaches and alike the trends known for CE data. Based on this analogy, we regard the probabilistic interpretation of MPS STR data fit for forensic DNA casework. In addition, guidelines were derived on when to apply LR calculations to MPS autosomal STR data and report the corresponding results.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.fsigen.2021.102489DOI Listing
May 2021

STRNaming: Generating simple, informative names for sequenced STR alleles in a standardised and automated manner.

Forensic Sci Int Genet 2021 May 29;52:102473. Epub 2021 Jan 29.

Division of Biological Traces, Netherlands Forensic Institute, The Hague, The Netherlands.

The introduction of Massively Parallel Sequencing in the forensic domain has exposed the need for comprehensive nomenclature of sequenced Short Tandem Repeat (STR) alleles. In general, three strategies are at hand: 1) the full sequence mapped to the human genome reference sequence, which ensures exact data exchange; 2) shortened, human-readable formats for forensic reporting and data presentation and 3) very short codes that enable compact figures and tables but do not convey any sequence information. Here, we describe an algorithm of the second type: STRNaming, which generates human-readable names for sequenced STR alleles. STRNaming is guided by a reference sequence at each locus and then functions independently to automatically assign a unique, sequence-descriptive name that also includes the capillary electrophoresis allele number. STRNaming settings were established based on preferences that were surveyed internationally in the forensic community. These settings ensure that a small change in the sequence corresponds to a small change in the allele name, which is helpful for recognising for instance stutter products. Sequence variants outside of the repeat units are indicated as simple variant calls. Since the STR name is sequence-descriptive, the sequence can be traced back from the allele name. Because STRNaming is fully guided by an assignable reference sequence, no central coordination or configuration is required and the method will work for any STR locus, be it autosomal, Y-, X-chromosomal in current or future use. The algorithm is publicly available online and offline.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.fsigen.2021.102473DOI Listing
May 2021

Reducing the Number of Mismatches between Hairs and Buccal References When Analysing mtDNA Heteroplasmic Variation by Massively Parallel Sequencing.

Genes (Basel) 2020 11 16;11(11). Epub 2020 Nov 16.

Netherlands Forensic Institute, Division of Biological Traces, Laan van Ypenburg 6, 2497GB The Hague, The Netherlands.

In forensics, mitochondrial DNA (mtDNA) analysis is foremost applied to rootless hairs often lacking detectable nuclear DNA. Sanger sequencing is the routine mtDNA method in most forensic laboratories, even though interpretation of mixed samples and heteroplasmic sites can be challenging. Individuals may hold cells with low-level heteroplasmy variants below the detection threshold and other cells where this minor variant is the major one. This difference may be interpreted as a mismatch between reference and evidentiary trace samples, such as buccal specimens and rootless hairs. Such mismatches may be solved by Massively Parallel Sequencing (MPS), allowing more sensitive quantitative analysis for mixed positions than Sanger. The mtDNA control region was analysed in buccal reference samples from 26 individuals and 475 corresponding hairs by MPS and compared to Sanger sequencing data generated on the same samples. With MPS, mixed contributions down to 3% were regarded, leading to a substantial increase in the frequency of heteroplasmy. Our results demonstrate that previously reported mismatches between buccal reference and hair shaft samples by Sanger are detected as low-level heteroplasmy by MPS. A detailed overview of buccal and hair heteroplasmy is provided and implications for MPS-based mtDNA analysis in the context of forensic cases are discussed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/genes11111355DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7696041PMC
November 2020

Correction to: The Dutch Y-chromosomal landscape.

Eur J Hum Genet 2020 Mar;28(3):399

Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41431-019-0528-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7028942PMC
March 2020

HIrisPlex-S system for eye, hair, and skin color prediction from DNA: Massively parallel sequencing solutions for two common forensically used platforms.

Forensic Sci Int Genet 2019 11 26;43:102152. Epub 2019 Aug 26.

Department of Genetic Identification, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands. Electronic address:

Forensic DNA Phenotyping (FDP) provides the ability to predict externally visible characteristics from minute amounts of crime scene DNA, which can help find unknown perpetrators who are typically unidentifiable via conventional forensic DNA profiling. Fundamental human genetics research has led to a better understanding of the specific DNA variants responsible for physical appearance characteristics, particularly eye, hair, and skin color. Recently, we introduced the HIrisPlex-S system for the simultaneous prediction of eye, hair, and skin color based on 41 DNA variants generated from two forensically validated SNaPshot multiplex assays using capillary electrophoresis (CE). Here we introduce massively parallel sequencing (MPS) solutions for the HIrisPlex-S (HPS) system on two MPS platforms commonly used in forensics, Ion Torrent and MiSeq, that cover all 41 DNA variants in a single assay, respectively. Additionally, we present the forensic developmental validation of the two HPS-MPS assays. The Ion Torrent MPS assay, based on Ion AmpliSeq technology, illustrated the successful generation of full HIrisPlex-S genotypic profiles from 100 pg of input control DNA, while the MiSeq MPS assay based on an in-house design yielded complete profiles from 250 pg of input DNA. Assessing simulated forensic casework samples such as saliva, hair (bulb), blood, semen, and low quantity touch DNA, as well as artificially damaged DNA samples, concordance testing, and samples from numerous species, all illustrated the ability of both versions of the HIrisPlex-S MPS assay to produce results that motivate forensic applications. By also providing an integrated bioinformatics analysis pipeline, MPS data can now be analyzed and a file generated for upload to the publically accessible HIrisPlex online webtool (https://hirisplex.erasmusmc.nl). In addition, we updated the website to accept VCF input data for those with genome sequence data. We thus provide a user-friendly and semi-automated MPS workflow from DNA sample to individual eye, hair, and skin color prediction probabilities. Furthermore, we present a 2-person mixture separation tool that not only assesses genotype reliability with regards genotyping confidence but also provides the most fitting mixture scenario for both minor and major contributors, including profile separation. We envision this MPS implementation of the HIrisPlex-S system for eye, hair, and skin color prediction from DNA as a starting point for further expanding MPS-based forensic DNA phenotyping. This may include the future addition of SNPs predictive for more externally visible characteristics, as well as SNPs for bio-geographic ancestry inference, provided the statistical framework for DNA prediction of these traits is in place.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.fsigen.2019.102152DOI Listing
November 2019

The Dutch Y-chromosomal landscape.

Eur J Hum Genet 2020 03 5;28(3):287-299. Epub 2019 Sep 5.

Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands.

Previous studies indicated existing, albeit limited, genetic-geographic population substructure in the Dutch population based on genome-wide data and a lack of this for mitochondrial SNP based data. Despite the aforementioned studies, Y-chromosomal SNP data from the Netherlands remain scarce and do not cover the territory of the Netherlands well enough to allow a reliable investigation of genetic-geographic population substructure. Here we provide the first substantial dataset of detailed spatial Y-chromosomal haplogroup information in 2085 males collected across the Netherlands and supplemented with previously published data from northern Belgium. We found Y-chromosomal evidence for genetic-geographic population substructure, and several Y-haplogroups demonstrating significant clinal frequency distributions in different directions. By means of prediction surface maps we could visualize (complex) distribution patterns of individual Y-haplogroups in detail. These results highlight the value of a micro-geographic approach and are of great use for forensic and epidemiological investigations and our understanding of the Dutch population history. Moreover, the previously noted absence of genetic-geographic population substructure in the Netherlands based on mitochondrial DNA in contrast to our Y-chromosome results, hints at different population histories for women and men in the Netherlands.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41431-019-0496-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7029002PMC
March 2020

Towards broadening Forensic DNA Phenotyping beyond pigmentation: Improving the prediction of head hair shape from DNA.

Forensic Sci Int Genet 2018 11 29;37:241-251. Epub 2018 Aug 29.

University of Chinese Academy of Sciences, 19 Yuquan Road, Shijingshan, Beijing, 100049, PR China; Chinese Academy of Sciences Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road Shanghai, 200031, PR China; State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory of Contemporary Anthropology, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, 2005 Song Hu Road Shanghai, 200438, PR China.

Human head hair shape, commonly classified as straight, wavy, curly or frizzy, is an attractive target for Forensic DNA Phenotyping and other applications of human appearance prediction from DNA such as in paleogenetics. The genetic knowledge underlying head hair shape variation was recently improved by the outcome of a series of genome-wide association and replication studies in a total of 26,964 subjects, highlighting 12 loci of which 8 were novel and introducing a prediction model for Europeans based on 14 SNPs. In the present study, we evaluated the capacity of DNA-based head hair shape prediction by investigating an extended set of candidate SNP predictors and by using an independent set of samples for model validation. Prediction model building was carried out in 9674 subjects (6068 from Europe, 2899 from Asia and 707 of admixed European and Asian ancestries), used previously, by considering a novel list of 90 candidate SNPs. For model validation, genotype and phenotype data were newly collected in 2415 independent subjects (2138 Europeans and 277 non-Europeans) by applying two targeted massively parallel sequencing platforms, Ion Torrent PGM and MiSeq, or the MassARRAY platform. A binomial model was developed to predict straight vs. non-straight hair based on 32 SNPs from 26 genetic loci we identified as significantly contributing to the model. This model achieved prediction accuracies, expressed as AUC, of 0.664 in Europeans and 0.789 in non-Europeans; the statistically significant difference was explained mostly by the effect of one EDAR SNP in non-Europeans. Considering sex and age, in addition to the SNPs, slightly and insignificantly increased the prediction accuracies (AUC of 0.680 and 0.800, respectively). Based on the sample size and candidate DNA markers investigated, this study provides the most robust, validated, and accurate statistical prediction models and SNP predictor marker sets currently available for predicting head hair shape from DNA, providing the next step towards broadening Forensic DNA Phenotyping beyond pigmentation traits.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.fsigen.2018.08.017DOI Listing
November 2018

Short hypervariable microhaplotypes: A novel set of very short high discriminating power loci without stutter artefacts.

Forensic Sci Int Genet 2018 07 22;35:169-175. Epub 2018 May 22.

Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333, ZC, Leiden, The Netherlands. Electronic address:

Since two decades, short tandem repeats (STRs) are the preferred markers for human identification, routinely analysed by fragment length analysis. Here we present a novel set of short hypervariable autosomal microhaplotypes (MH) that have four or more SNPs in a span of less than 70 nucleotides (nt). These MHs display a discriminating power approaching that of STRs and provide a powerful alternative for the analysis;1;is of forensic samples that are problematic when the STR fragment size range exceeds the integrity range of severely degraded DNA or when multiple donors contribute to an evidentiary stain and STR stutter artefacts complicate profile interpretation. MH typing was developed using the power of massively parallel sequencing (MPS) enabling new powerful, fast and efficient SNP-based approaches. MH candidates were obtained from queries in data of the 1000 Genomes, and Genome of the Netherlands (GoNL) projects. Wet-lab analysis of 276 globally dispersed samples and 97 samples of nine large CEPH families assisted locus selection and corroboration of informative value. We infer that MHs represent an alternative marker type with good discriminating power per locus (allowing the use of a limited number of loci), small amplicon sizes and absence of stutter artefacts that can be especially helpful when unbalanced mixed samples are submitted for human identification.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.fsigen.2018.05.008DOI Listing
July 2018

Length and repeat-sequence variation in 58 STRs and 94 SNPs in two Spanish populations.

Forensic Sci Int Genet 2017 09 16;30:66-70. Epub 2017 Jun 16.

Institut de Biologia Evolutiva (UPF-CSIC), Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, 08003 Barcelona, Catalonia, Spain. Electronic address:

We have genotyped the 58 STRs (27 autosomal, 24 Y-STRs and 7 X-STRs) and 94 autosomal SNPs in Illumina ForenSeq™ Primer Mix A in 88 Spanish Roma (Gypsy) samples and 143 Catalans. Since this platform is based in massive parallel sequencing, we have used simple R scripts to uncover the sequence variation in the repeat region. Thus, we have found, across 58 STRs, 541 length-based alleles, which, after considering repeat-sequence variation, became 804 different alleles. All loci in both populations were in Hardy-Weinberg equilibrium. F between both populations was 0.0178 for autosomal SNPs, 0.0146 for autosomal STRs, 0.0101 for X-STRs and 0.1866 for Y-STRs. Combined a priori statistics showed quite large; for instance, pooling all the autosomal loci, the a priori probabilities of discriminating a suspect become 1-(2.3×10) and 1-(5.9×10), for Roma and Catalans respectively, and the chances of excluding a false father in a trio are 1-(2.6×10) and 1-(2.0×10).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.fsigen.2017.06.006DOI Listing
September 2017

FDSTools: A software package for analysis of massively parallel sequencing data with the ability to recognise and correct STR stutter and other PCR or sequencing noise.

Forensic Sci Int Genet 2017 03 27;27:27-40. Epub 2016 Nov 27.

Department of Human Genetics, Leiden University Medical Center, Leiden, 2300 RC, The Netherlands. Electronic address:

Massively parallel sequencing (MPS) is on the advent of a broad scale application in forensic research and casework. The improved capabilities to analyse evidentiary traces representing unbalanced mixtures is often mentioned as one of the major advantages of this technique. However, most of the available software packages that analyse forensic short tandem repeat (STR) sequencing data are not well suited for high throughput analysis of such mixed traces. The largest challenge is the presence of stutter artefacts in STR amplifications, which are not readily discerned from minor contributions. FDSTools is an open-source software solution developed for this purpose. The level of stutter formation is influenced by various aspects of the sequence, such as the length of the longest uninterrupted stretch occurring in an STR. When MPS is used, STRs are evaluated as sequence variants that each have particular stutter characteristics which can be precisely determined. FDSTools uses a database of reference samples to determine stutter and other systemic PCR or sequencing artefacts for each individual allele. In addition, stutter models are created for each repeating element in order to predict stutter artefacts for alleles that are not included in the reference set. This information is subsequently used to recognise and compensate for the noise in a sequence profile. The result is a better representation of the true composition of a sample. Using Promega Powerseq™ Auto System data from 450 reference samples and 31 two-person mixtures, we show that the FDSTools correction module decreases stutter ratios above 20% to below 3%. Consequently, much lower levels of contributions in the mixed traces are detected. FDSTools contains modules to visualise the data in an interactive format allowing users to filter data with their own preferred thresholds.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.fsigen.2016.11.007DOI Listing
March 2017

Massively parallel sequencing of short tandem repeats-Population data and mixture analysis results for the PowerSeq™ system.

Forensic Sci Int Genet 2016 09 7;24:86-96. Epub 2016 Jun 7.

Forensic Laboratory for DNA Research, Department of Human Genetics, Leiden University Medical Centre, Postzone S 05 P, P.O. Box 9600, 2300 RC Leiden, The Netherlands. Electronic address:

Current forensic DNA analysis predominantly involves identification of human donors by analysis of short tandem repeats (STRs) using Capillary Electrophoresis (CE). Recent developments in Massively Parallel Sequencing (MPS) technologies offer new possibilities in analysis of STRs since they might overcome some of the limitations of CE analysis. In this study 17 STRs and Amelogenin were sequenced in high coverage using a prototype version of the Promega PowerSeq™ system for 297 population samples from the Netherlands, Nepal, Bhutan and Central African Pygmies. In addition, 45 two-person mixtures with different minor contributions down to 1% were analysed to investigate the performance of this system for mixed samples. Regarding fragment length, complete concordance between the MPS and CE-based data was found, marking the reliability of MPS PowerSeq™ system. As expected, MPS presented a broader allele range and higher power of discrimination and exclusion rate. The high coverage sequencing data were used to determine stutter characteristics for all loci and stutter ratios were compared to CE data. The separation of alleles with the same length but exhibiting different stutter ratios lowers the overall variation in stutter ratio and helps in differentiation of stutters from genuine alleles in mixed samples. All alleles of the minor contributors were detected in the sequence reads even for the 1% contributions, but analysis of mixtures below 5% without prior information of the mixture ratio is complicated by PCR and sequencing artefacts.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.fsigen.2016.05.016DOI Listing
September 2016

Analysis of 36 Y-STR marker units including a concordance study among 2085 Dutch males.

Forensic Sci Int Genet 2015 Jan 23;14:174-81. Epub 2014 Oct 23.

Forensic Laboratory for DNA Research, Department of Human Genetics, Leiden University Medical Center, Postzone S-05-P, P.O. Box 9600, 2300 RC Leiden, The Netherlands. Electronic address:

The genotypes of 36 Y-chromosomal short tandem repeat (Y-STR) marker units were analysed in a Dutch population sample of 2085 males. Profiling results were compared for several partially overlapping kits, i.e. PowerPlex Y, Yfiler, PowerPlex Y23, and two in-house designed multiplexes with rapidly mutating Y-STRs. Nineteen Y-STR marker units, of which two are rapidly mutating, reside in at least two of these multiplexes, and for these markers concordance testing was performed. Two samples showed discordant genotyping results and the probable causative base change was revealed by Sanger sequencing. In addition, we encountered concordant, but aberrant genotyping results including one allele with low peak height and several null alleles. For 12 samples, this involved a null allele in two adjacent loci suggesting a large and recurrent deletion as the samples represent three distinct haplogroups. For each marker unit, the allele counts and frequencies are presented, as are the haplotype counts and haplotype diversities for several combinations of markers.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.fsigen.2014.10.012DOI Listing
January 2015

Data concatenation, Bayesian concordance and coalescent-based analyses of the species tree for the rapid radiation of Triturus newts.

PLoS One 2014 22;9(10):e111011. Epub 2014 Oct 22.

Institute of Environmental Sciences, Jagiellonian University, Kraków, Poland.

The phylogenetic relationships for rapid species radiations are difficult to disentangle. Here we study one such case, namely the genus Triturus, which is composed of the marbled and crested newts. We analyze data for 38 genetic markers, positioned in 3-prime untranslated regions of protein-coding genes, obtained with 454 sequencing. Our dataset includes twenty Triturus newts and represents all nine species. Bayesian analysis of population structure allocates all individuals to their respective species. The branching patterns obtained by data concatenation, Bayesian concordance analysis and coalescent-based estimations of the species tree differ from one another. The data concatenation based species tree shows high branch support but branching order is considerably affected by allele choice in the case of heterozygotes in the concatenation process. Bayesian concordance analysis expresses the conflict between individual gene trees for part of the Triturus species tree as low concordance factors. The coalescent-based species tree is relatively similar to a previously published species tree based upon morphology and full mtDNA and any conflicting internal branches are not highly supported. Our findings reflect high gene tree discordance due to incomplete lineage sorting (possibly aggravated by hybridization) in combination with low information content of the markers employed (as can be expected for relatively recent species radiations). This case study highlights the complexity of resolving rapid radiations and we acknowledge that to convincingly resolve the Triturus species tree even more genes will have to be consulted.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0111011PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4206468PMC
December 2015

The contribution of DNA metabarcoding to fungal conservation: diversity assessment, habitat partitioning and mapping red-listed fungi in protected coastal Salix repens communities in the Netherlands.

PLoS One 2014 17;9(6):e99852. Epub 2014 Jun 17.

Naturalis Biodiversity Center, Leiden, The Netherlands.

Western European coastal sand dunes are highly important for nature conservation. Communities of the creeping willow (Salix repens) represent one of the most characteristic and diverse vegetation types in the dunes. We report here the results of the first kingdom-wide fungal diversity assessment in S. repens coastal dune vegetation. We carried out massively parallel pyrosequencing of ITS rDNA from soil samples taken at ten sites in an extended area of joined nature reserves located along the North Sea coast of the Netherlands, representing habitats with varying soil pH and moisture levels. Fungal communities in Salix repens beds are highly diverse and we detected 1211 non-singleton fungal 97% sequence similarity OTUs after analyzing 688,434 ITS2 rDNA sequences. Our comparison along a north-south transect indicated strong correlation between soil pH and fungal community composition. The total fungal richness and the number OTUs of most fungal taxonomic groups negatively correlated with higher soil pH, with some exceptions. With regard to ecological groups, dark-septate endophytic fungi were more diverse in acidic soils, ectomycorrhizal fungi were represented by more OTUs in calcareous sites, while detected arbuscular mycorrhizal genera fungi showed opposing trends regarding pH. Furthermore, we detected numerous red listed species in our samples often from previously unknown locations, indicating that some of the fungal species currently considered rare may be more abundant in Dutch S. repens communities than previously thought.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0099852PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4061046PMC
February 2015

Toward male individualization with rapidly mutating y-chromosomal short tandem repeats.

Hum Mutat 2014 Aug 14;35(8):1021-32. Epub 2014 Jul 14.

Department of Forensic Molecular Biology, Erasmus MC University Medical Centre Rotterdam, Rotterdam, The Netherlands; Office of the Chief Forensic Scientist, Victoria Police Forensic Services Department, Macleod, Victoria, Australia.

Relevant for various areas of human genetics, Y-chromosomal short tandem repeats (Y-STRs) are commonly used for testing close paternal relationships among individuals and populations, and for male lineage identification. However, even the widely used 17-loci Yfiler set cannot resolve individuals and populations completely. Here, 52 centers generated quality-controlled data of 13 rapidly mutating (RM) Y-STRs in 14,644 related and unrelated males from 111 worldwide populations. Strikingly, >99% of the 12,272 unrelated males were completely individualized. Haplotype diversity was extremely high (global: 0.9999985, regional: 0.99836-0.9999988). Haplotype sharing between populations was almost absent except for six (0.05%) of the 12,156 haplotypes. Haplotype sharing within populations was generally rare (0.8% nonunique haplotypes), significantly lower in urban (0.9%) than rural (2.1%) and highest in endogamous groups (14.3%). Analysis of molecular variance revealed 99.98% of variation within populations, 0.018% among populations within groups, and 0.002% among groups. Of the 2,372 newly and 156 previously typed male relative pairs, 29% were differentiated including 27% of the 2,378 father-son pairs. Relative to Yfiler, haplotype diversity was increased in 86% of the populations tested and overall male relative differentiation was raised by 23.5%. Our study demonstrates the value of RM Y-STRs in identifying and separating unrelated and related males and provides a reference database.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/humu.22599DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4145662PMC
August 2014

Comparing six commercial autosomal STR kits in a large Dutch population sample.

Forensic Sci Int Genet 2014 May 4;10:55-63. Epub 2014 Feb 4.

Forensic Laboratory for DNA Research, Department of Human Genetics, Leiden University Medical Centre, Postzone S-05-P, P.O. Box 9600, 2300 RC Leiden, The Netherlands. Electronic address:

Regularly, STR results obtained with different PCR amplification kits are compared, for instance with old cases, when revisiting cold cases or when addressing cross-border crimes. It is known that differences in primer design for the same loci in different kits may give rise to null alleles or shifted alleles. In this study, the genotyping results of 2085 Dutch male samples were compared for six autosomal STR kits (Promega's PowerPlex(®) 16, ESX-16 and ESI-17 Systems, Qiagen's Investigator(®) ESSplex Kit and Applied Biosystems' AmpFlSTR(®) Identifiler and NGM PCR Amplification Kits). A total of 19 discordant autosomal genotyping results were obtained that were examined by sequence analysis using Roche-454 next generation sequencing and/or Sanger sequencing. A further 25 discordances were found and sequenced for the Amelogenin locus. The 24 samples showing the same primer binding site mutation at the Amelogenin locus were subjected to X-STR analysis in order to assess whether they could share a common origin, which appeared not to be the case. Based on the sequencing results, we set the final genotypes and determined the allele frequencies of 23 autosomal STRs for the Dutch reference database.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.fsigen.2014.01.008DOI Listing
May 2014

A linguistically informed autosomal STR survey of human populations residing in the greater Himalayan region.

PLoS One 2014 10;9(3):e91534. Epub 2014 Mar 10.

MGC Department of Human and Clinical Genetics, Leiden University Medical Centre, Leiden, the Netherlands.

The greater Himalayan region demarcates two of the most prominent linguistic phyla in Asia: Tibeto-Burman and Indo-European. Previous genetic surveys, mainly using Y-chromosome polymorphisms and/or mitochondrial DNA polymorphisms suggested a substantially reduced geneflow between populations belonging to these two phyla. These studies, however, have mainly focussed on populations residing far to the north and/or south of this mountain range, and have not been able to study geneflow patterns within the greater Himalayan region itself. We now report a detailed, linguistically informed, genetic survey of Tibeto-Burman and Indo-European speakers from the Himalayan countries Nepal and Bhutan based on autosomal microsatellite markers and compare these populations with surrounding regions. The genetic differentiation between populations within the Himalayas seems to be much higher than between populations in the neighbouring countries. We also observe a remarkable genetic differentiation between the Tibeto-Burman speaking populations on the one hand and Indo-European speaking populations on the other, suggesting that language and geography have played an equally large role in defining the genetic composition of present-day populations within the Himalayas.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0091534PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3948894PMC
March 2016

TSSV: a tool for characterization of complex allelic variants in pure and mixed genomes.

Bioinformatics 2014 Jun 13;30(12):1651-9. Epub 2014 Feb 13.

Department of Human Genetic, Leiden Genome Technology Center, Leiden University Medical Center, Leiden, 2300 RC, The Netherlands and Netherlands Bioinformatics Centre, Leiden, The NetherlandsDepartment of Human Genetic, Leiden Genome Technology Center, Leiden University Medical Center, Leiden, 2300 RC, The Netherlands and Netherlands Bioinformatics Centre, Leiden, The NetherlandsDepartment of Human Genetic, Leiden Genome Technology Center, Leiden University Medical Center, Leiden, 2300 RC, The Netherlands and Netherlands Bioinformatics Centre, Leiden, The Netherlands.

Motivation: Advances in sequencing technologies and computational algorithms have enabled the study of genomic variants to dissect their functional consequence. Despite this unprecedented progress, current tools fail to reliably detect and characterize more complex allelic variants, such as short tandem repeats (STRs). We developed TSSV as an efficient and sensitive tool to specifically profile all allelic variants present in targeted loci. Based on its design, requiring only two short flanking sequences, TSSV can work without the use of a complete reference sequence to reliably profile highly polymorphic, repetitive or uncharacterized regions.

Results: We show that TSSV can accurately determine allelic STR structures in mixtures with 10% representation of minor alleles or complex mixtures in which a single STR allele is shared. Furthermore, we show the universal utility of TSSV in two other independent studies: characterizing de novo mutations introduced by transcription activator-like effector nucleases (TALENs) and profiling the noise and systematic errors in an IonTorrent sequencing experiment. TSSV complements the existing tools by aiding the study of highly polymorphic and complex regions and provides a high-resolution map that can be used in a wide range of applications, from personal genomics to forensic analysis and clinical diagnostics.

Availability And Implementation: We have implemented TSSV as a Python package that can be installed through the command-line using pip install TSSV command. Its source code and documentation are available at https://pypi.python.org/pypi/tssv and http://www.lgtc.nl/tssv.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/bioinformatics/btu068DOI Listing
June 2014

Quality assessment of the genetic test for familial hypercholesterolemia in the Netherlands.

Cholesterol 2013 8;2013:531658. Epub 2013 Jul 8.

Foundation for the Identification of Persons with Inherited Hypercholesterolemia (StOEH), Amsterdam, The Netherlands.

Introduction. Familial hypercholesterolemia (FH) is an inherited disorder associated with a severely increased risk of cardiovascular disease. Although DNA test results in FH are associated with important medical and ethical consequences, data on accuracy of genetic tests is scarce. Methods. Therefore, we performed a prospective study to assess the overall accuracy of the DNA test used in the genetic cascade screening program for FH in The Netherlands. Individuals aged 18 years and older tested for one of the 5 most prevalent FH mutations, were included consecutively. DNA samples were analyzed by the reference and a counter-expertise laboratory following a standardized procedure. Results. 1003 cases were included. In the end, 317 (32%) carried an FH mutation, whereas in 686 (69%) samples no mutation was found. The overall accuracy of the reference laboratory was 99.8%, with two false positive results identified by the counter-expertise laboratory. Conclusion. The currently used mutation analysis is associated with a very low error rate. Therefore, we do not recommend routine use of duplicate testing.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2013/531658DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3722838PMC
August 2013

Ancestral stories of Ghanaian Bimoba reflect millennia-old genetic lineages.

PLoS One 2013 12;8(6):e65690. Epub 2013 Jun 12.

Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands.

Oral history and oral genealogies are mechanisms of collective memory and a main cultural heritage of many populations without a writing system. In the effort to analytically address the correspondence between genetic data and historical genealogies, anthropologists hypothesised that genealogies evolve through time, ultimately containing three parts: literal--where the most recent ancestry is truthfully represented; intended--ancestry is inferred and reflects political relations among groups; and mythical--that does not represent current social reality. While numerous studies discuss oral genealogies, to our knowledge no genetic studies have been able to investigate to what extent genetic relatedness corresponds to the literal and intended parts of oral genealogies. We report on the correspondence between genetic data and oral genealogies among Bimoba males in a single village in North-Eastern Ghana. We compared the pairwise mismatch distribution of Y chromosome short tandem repeat (Y-STR) haplotypes among all lineages present in this village to the self-reported (oral) relatedness. We found that Bimoba are able to correctly identify unrelated individuals in 92% of the cases. In contrast, they are able to correctly identify related individuals only in 38% of the cases, which can be explained by three processes: (1) the compression of genealogies, leading to increasing inaccuracy with increasing genealogical distance, (2) inclusions into the lineage from intended relations such as clan co-option or adoptions, and (3) false paternities, which in this study were found to have a minor effect on the correspondence between genetic data and oral genealogies. In addition, we observed that 70% of unrelated pairs have from six to eight Y-STR differences, a diversification peak which we attribute to an ancient West African expansion dating around 9454 years ago. We conclude that, despite all caveats, oral genealogies are reflecting ancient lineages more accurately than previously thought.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0065690PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3680464PMC
January 2014

Indian Ocean crossroads: human genetic origin and population structure in the Maldives.

Am J Phys Anthropol 2013 May 21;151(1):58-67. Epub 2013 Mar 21.

Department of Human Genetics, Leiden University Medical Center, Postzone S5, 2300 RC Leiden, The Netherlands.

The Maldives are an 850 km-long string of atolls located centrally in the northern Indian Ocean basin. Because of this geographic situation, the present-day Maldivian population has potential for uncovering genetic signatures of historic migration events in the region. We therefore studied autosomal DNA-, mitochondrial DNA-, and Y-chromosomal DNA markers in a representative sample of 141 unrelated Maldivians, with 119 from six major settlements. We found a total of 63 different mtDNA haplotypes that could be allocated to 29 mtDNA haplogroups, mostly within the M, R, and U clades. We found 66 different Y-STR haplotypes in 10 Y-chromosome haplogroups, predominantly H1, J2, L, R1a1a, and R2. Parental admixture analysis for mtDNA- and Y-haplogroup data indicates a strong genetic link between the Maldive Islands and mainland South Asia, and excludes significant gene flow from Southeast Asia. Paternal admixture from West Asia is detected, but cannot be distinguished from admixture from South Asia. Maternal admixture from West Asia is excluded. Within the Maldives, we find a subtle genetic substructure in all marker systems that is not directly related to geographic distance or linguistic dialect. We found reduced Y-STR diversity and reduced male-mediated gene flow between atolls, suggesting independent male founder effects for each atoll. Detected reduced female-mediated gene flow between atolls confirms a Maldives-specific history of matrilocality. In conclusion, our new genetic data agree with the commonly reported Maldivian ancestry in South Asia, but furthermore suggest multiple, independent immigration events and asymmetrical migration of females and males across the archipelago.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ajpa.22256DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3652038PMC
May 2013

The influence of clan structure on the genetic variation in a single Ghanaian village.

Eur J Hum Genet 2013 Oct 27;21(10):1134-9. Epub 2013 Feb 27.

1] Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands [2] Department of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, The Netherlands.

Socioeconomic and cultural factors are thought to have an important role in influencing human population genetic structure. To explain such population structure differences, most studies analyse genetic differences among widely dispersed human populations. In contrast, we have studied the genetic structure of an ethnic group occupying a single village in north-eastern Ghana. We found a markedly skewed male population substructure because of an almost complete lack of male gene flow among Bimoba clans in this village. We also observed a deep male substructure within one of the clans in this village. Among all males, we observed only three Y-single-nucleotide polymorphism (SNP) haplogroups: E1b1a*-M2, E1b1a7a*-U174 and E1b1a8a*-U209, P277, P278. In contrast to the marked Y-chromosomal substructure, mitochondrial DNA HVS-1 sequence variation and autosomal short-tandem repeats variation patterns indicate high genetic diversities and a virtually random female-mediated gene flow among clans. On the extreme micro-geographical scale of this single Bimoba village, correspondence between the Y-chromosome lineages and clan membership could be due to the combined effects of the strict patrilocal and patrilineal structure. If translated to larger geographic scales, our results would imply that the extent of variation in uniparentally inherited genetic markers, which are typically associated with historical migration on a continental scale, could equally likely be the result of many small and different cumulative effects of social factors such as clan membership that act at a local scale. Such local scale effects should therefore be considered in genetic studies, especially those that use uniparental markers, before making inferences about human history at large.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/ejhg.2013.12DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3778349PMC
October 2013

Improved analysis of long STR amplicons from degraded single source and mixed DNA.

Int J Legal Med 2013 Jul 10;127(4):741-7. Epub 2013 Jan 10.

Department of Human Biological Traces (R&D), Netherlands Forensic Institute, P.O. Box 24044, 2490 AA, The Hague, The Netherlands.

DNA profiles from degraded samples often suffer from information loss at the longer short tandem repeat (STR) loci. Sensitising the reactions, either by performing additional PCR cycles or increasing the capillary electrophoresis injection settings, carries the risk of over-amplifying or overloading the shorter fragments. We explored whether profiling of degraded DNA can be improved by preferential capturing of the longer amplified fragments. To this aim, a post-PCR purification protocol was developed that is based on AMPure XP beads that have size-selective properties. A comparison was made with an unselective post-PCR purification system (DTR gel filtration) and no purification of the PCR products. Besides a set of differently and serially degraded single source samples, unequal mixtures of degraded DNAs were analysed, in order to extract more genotyping information for the minor contributor without overloading the major component at the shorter amplicons. Purification by the AMPure protocol resulted in higher peak heights especially for the longer amplicons, while DTR gel filtration gave higher peaks for all amplicon sizes. Both purification methods presented more detected alleles, with the AMPure protocol performing slightly better, on average. In conclusion, the in-house developed AMPure protocol can be employed to improve STR profile analysis of degraded single source and (unequally) mixed DNA samples.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00414-012-0816-1DOI Listing
July 2013

Combining results of forensic STR kits: HDplex validation including allelic association and linkage testing with NGM and Identifiler loci.

Int J Legal Med 2012 Sep 3;126(5):781-9. Epub 2012 Jul 3.

Department of Human Biological Traces (R&D), Netherlands Forensic Institute, P.O. Box 24044, 2490 AA, The Hague, The Netherlands.

The autosomal short tandem repeat (STR) kits that are currently used in forensic science have a high discrimination power. However, this discrimination power is sometimes not sufficient for complex kinship analyses or decreases when alleles are missing due to degradation of the DNA. The Investigator HDplex kit contains nine STRs that are additional to the commonly used forensic markers, and we validated this kit to assist human identification. With the increasing number of markers it becomes inevitable that forensic and kinship analyses include two or more STRs present on the same chromosome. To examine whether such markers can be regarded as independent, we evaluated the 30 STRs present in NGM, Identifiler and HDplex. Among these 30 markers, 17 syntenic STR pairs can be formed. Allelic association between these pairs was examined using 335 Dutch reference samples and no linkage disequilibrium was detected, which makes it possible to use the product rule for profile probability calculations in unrelated individuals. Linkage between syntenic STRs was studied by determining the recombination fraction between them in five three-generation CEPH families. The recombination fractions were compared to the physical and genetic distances between the markers. For most types of pedigrees, the kinship analyses can be performed using the product rule, and for those cases that require an alternative calculation method (Gill et al., Forensic Sci Int Genet 6:477-486, 2011), the recombination fractions as determined in this study can be used. Finally, we calculated the (combined) match probabilities, for the supplementary genotyping results of HDplex, NGM and Identifiler.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00414-012-0724-4DOI Listing
September 2012

Dissecting the genetic make-up of North-East Sardinia using a large set of haploid and autosomal markers.

Eur J Hum Genet 2012 Sep 29;20(9):956-64. Epub 2012 Feb 29.

Department of Clinical Genetics, Medical Genomics, Free University Medical Center, Amsterdam, The Netherlands.

Sardinia has been used for genetic studies because of its historical isolation, genetic homogeneity and increased prevalence of certain rare diseases. Controversy remains concerning the genetic substructure and the extent of genetic homogeneity, which has implications for the design of genome-wide association studies (GWAS). We revisited this issue by examining the genetic make-up of a sample from North-East Sardinia using a dense set of autosomal, Y chromosome and mitochondrial markers to assess the potential of the sample for GWAS and fine mapping studies. We genotyped individuals for 500K single-nucleotide polymorphisms, Y chromosome markers and sequenced the mitochondrial hypervariable (HVI-HVII) regions. We identified major haplogroups and compared these with other populations. We estimated linkage disequilibrium (LD) and haplotype diversity across autosomal markers, and compared these with other populations. Our results show that within Sardinia there is no major population substructure and thus it can be considered a genetically homogenous population. We did not find substantial differences in the extent of LD in Sardinians compared with other populations. However, we showed that at least 9% of genomic regions in Sardinians differed in LD structure, which is helpful for identifying functional variants using fine mapping. We concluded that Sardinia is a powerful setting for genetic studies including GWAS and other mapping approaches.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/ejhg.2012.22DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3421114PMC
September 2012

Evaluating self-declared ancestry of U.S. Americans with autosomal, Y-chromosomal and mitochondrial DNA.

Hum Mutat 2010 Dec;31(12):E1875-93

Department of Forensic Molecular Biology, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands.

The current U.S. population represents an amalgam of individuals originating mainly from four continental regions (Africa, Europe, Asia and America). To study the genetic ancestry and compare with self-declared ancestry we have analyzed paternally, maternally and bi-parentally inherited DNA markers sensitive for indicating continental genetic ancestry in all four major U.S. American groups. We found that self-declared U.S. Hispanics and U.S. African Americans tend to show variable degrees of continental genetic admixture among the three genetic systems, with evidence for a marked sex-biased admixture history. Moreover, for these two groups we observed significant regional variation across the country in genetic admixture. In contrast, self-declared U.S. European and U.S. Asian Americans were genetically more homogeneous at the continental ancestry level. Two autosomal ancestry-sensitive markers located in skin pigmentation candidate genes showed significant differences in self-declared U.S. African Americans or U.S. European Americans, relative to their assumed parental populations from Africa or Europe. This provides genetic support for the importance of skin color in the complex process of ancestry identification.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/humu.21366DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3051415PMC
December 2010

Worldwide population analysis of the 4q and 10q subtelomeres identifies only four discrete interchromosomal sequence transfers in human evolution.

Am J Hum Genet 2010 Mar 4;86(3):364-77. Epub 2010 Mar 4.

Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands.

Subtelomeres are dynamic structures composed of blocks of homologous DNA sequences. These so-called duplicons are dispersed over many chromosome ends. We studied the human 4q and 10q subtelomeres, which contain the polymorphic macrosatellite repeat D4Z4 and which share high sequence similarity over a region of, on average, >200 kb. Sequence analysis of four polymorphic markers in the African, European, and Asian HAPMAP panels revealed 17 subtelomeric 4q and eight subtelomeric 10qter haplotypes. Haplotypes that are composed of a mixture of 4q and 10q sequences were detected at frequencies >10% in all three populations, seemingly supporting a mechanism of ongoing interchromosomal exchanges between these chromosomes. We constructed an evolutionary network of most haplotypes and identified the 4q haplotype ancestral to all 4q and 10q haplotypes. According to the network, all subtelomeres originate from only four discrete sequence-transfer events during human evolution, and haplotypes with mixtures of 4q- and 10q-specific sequences represent intermediate structures in the transition from 4q to 10q subtelomeres. Haplotype distribution studies on a large number of globally dispersed human DNA samples from the HGDP-CEPH panel supported our findings and show that all haplotypes were present before human migration out of Africa. D4Z4 repeat array contractions on the 4A161 haplotype cause Facioscapulohumeral muscular dystrophy (FSHD), whereas contractions on most other haplotypes are nonpathogenic. We propose that the limited occurrence of interchromosomal sequence transfers results in an accumulation of haplotype-specific polymorphisms that can explain the unique association of FSHD with D4Z4 contractions in a single 4q subtelomere.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ajhg.2010.01.035DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2833386PMC
March 2010

Specific sequence variations within the 4q35 region are associated with facioscapulohumeral muscular dystrophy.

Am J Hum Genet 2007 Nov 7;81(5):884-94. Epub 2007 Sep 7.

Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands.

Autosomal dominant facioscapulohumeral muscular dystrophy (FSHD) is mainly characterized by progressive wasting and weakness of the facial, shoulder, and upper-arm muscles. FSHD is caused by contraction of the macrosatellite repeat D4Z4 on chromosome 4q35. The D4Z4 repeat is very polymorphic in length, and D4Z4 rearrangements occur almost exclusively via intrachromosomal gene conversions. Several disease mechanisms have been proposed, but none of these models can comprehensively explain FSHD, because repeat contraction alone is not sufficient to cause disease. Almost-identical D4Z4-repeat arrays have been identified on chromosome 10q26 and on two equally common chromosome 4 variants, 4qA and 4qB. Yet only repeat contractions of D4Z4 on chromosome 4qA cause FSHD; contractions on the other chromosomes are nonpathogenic. We hypothesized that allele-specific sequence differences among 4qA, 4qB, and 10q alleles underlie the 4qA specificity of FSHD. Sequence variations between these alleles have been described before, but the extent and significance of these variations proximal to, within, and distal to D4Z4 have not been studied in detail. We examined additional sequence variations in the FSHD locus, including a relatively stable simple sequence-length polymorphism proximal to D4Z4, a single-nucleotide polymorphism (SNP) within D4Z4, and the A/B variation distal to D4Z4. On the basis of these polymorphisms, we demonstrate that the subtelomeric domain of chromosome 4q can be subdivided into nine distinct haplotypes, of which three carry the distal 4qA variation. Interestingly, we show that repeat contractions in two of the nine haplotypes, one of which is a 4qA haplotype, are not associated with FSHD. We also show that each of these haplotypes has its unique sequence signature, and we propose that specific SNPs in the disease haplotype are essential for the development of FSHD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1086/521986DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2265642PMC
November 2007