Aortic dissection and cocaine use

Most of the cocaine - deaths are said to be related to cardiovascular complications. This paper addresses a rather infrequent complication of chronic cocaine use, represented by the aortic dissection. The case in point pertains to a 45-year-old, caucasian male, substance abuser who suffered an aortic dissection following the use of cocaine. Blood concentrations of cocaine and benzoylecgonine were considered not to be within a potentially toxic range.     

Detection of stimulant drugs of abuse in maternal and neonatal hair

Exposure to drugs of abuse, particularly during pregnancy, is difficult to ascertain. Presently, there is sparse information on gestational exposure and fetal effects to potentially toxic drugs such as methamphetamine (MA) and cocaine; two of the most prevalent abused stimulants in North America. The Motherisk laboratory at the Hospital for Sick Children routinely carries out analysis of MA and cocaine in adult and infant hair. All mother–child pairs in whom at least one had cocaine and/or benzoylecgonine (BE), or MA detected in hair were identified from the Motherisk database. Eleven mother–infant pairs with positive hair for MA were identified. One infant (9%) had a negative MA result with a positive maternal result. There was not any positive infant hair with negative maternal hair for MA. MA concentrations in mothers and infants correlated positively and were not significantly different. Median cocaine concentrations were tenfold higher in hair of the mothers compared to the infants. Thirty-nine (40%) infants had negative cocaine and BE with positive maternal results. Mothers whose infants were cocaine positive had median cocaine significantly higher than those whose infants were negative. Infants’ cocaine in hair was positively correlated with maternal cocaine and BE. Infants’ BE correlated with maternal cocaine and BE concentrations. Fetal hair grows during the last trimester of pregnancy; therefore a positive neonatal hair result indicates maternal use after pregnancy is known, a strong indicator of maternal addiction. To our knowledge, this is the first report on fetal exposure to MA during pregnancy showing transplacental transfer of the drug, with accumulation in fetal hair. Transplacental exposure to cocaine of babies of addicted mothers is highly variable. Further research is needed to understand the mechanisms leading to placental defense against cocaine. The data were presented at the Hair Testing Meeting, Vadstena, Sweden, May 2006. We hereby state that we do not have a significant financial interest or other relationship with any product manufacturer or provider of services discussed in this article.     

Cocaine found in a child’s hair due to environmental exposure?

We report a case of a 6-year-old boy who had been living with his parents, both cocaine smokers, and who was urgently admitted to hospital for general distress. Upon examination, cocaine and cocaine metabolites were detected in hair and urine samples. These toxicological findings most likely indicate that the child had passively consumed the drug when living in a heavily contaminated environment.     

Individual variations of amitriptyline biotransformation examined in scalp hair samples

The identification of amitriptyline, nortriptyline and its hydroxy-metabolites including a subsequent measurement of concentration profiles in hair samples was carried out to evaluate the administration history of amitriptyline. Analyses were carried out using liquid chromatography—tandem mass spectrometry, which permits simultaneous identification of all relevant substances in hair at low target concentrations (limit of detection better than 0.5 pg/mg). Standard hair sample preparation was applied for the estimation of average substance concentration in a hair bundle, while segmentation of individual hairs was utilised to examine accurate concentration profiles. Replication of analyses demonstrated a good reproducibility of individual hair concentration profiles, which proved to coincide for all relevant compounds. Significant variations of metabolite ratios (e.g. nortriptyline to amitriptyline and E10- to Z10-hydroxynortriptyline) between individuals suggest a correlation between hair concentration and metabolic phenotype. Different concentration ratios of certain metabolites in hair are highly correlated, indicating a systematic association between demethylation and stereo-specificity of hydroxylation. The trans isomers of hydroxy-metabolites become significantly more prevalent with increasing degree of demethylation of amitriptyline or hydroxylation of amitriptyline. The data were presented at the Hair Testing Meeting, Vadstena, Sweden, May 2006. We hereby state that we do not have a significant financial interest or other relationship with any product manufacturer or provider of services discussed in this article.     

Heart rupture as an acute complication of cocaine abuse: A case report

The purpose of this study is to show a very rare complication of acute cocaine poisoning, namely heart rupture. In the present case report, acute cocaine intoxication caused massive myocardial infarction, resulting in heart rupture and cardiac tamponade. A crime scene investigation found a dead body on the street in a drug dealing district. Examination of the body showed no external injuries. A thorough autopsy was performed showing massive cardiac tamponade with 510 ml of blood within the pericardium and full-thickness tissue lesion at the posterior wall of the left ventricle of 3.5 × 3 cm. Histological examination in hematoxylin and eosin was performed and confirmed the interruption of the posterior wall of the left ventricle with the presence of blood. In fact, although the correlation between cocaine and myocardial damage is well established, the relationship between heart rupture and acute cocaine intoxication is an extremely rare event. Moreover, since there are, to date, few reports of similar deaths, our report provides useful information regarding sudden death in a cocaine abuser. It is, therefore, of crucial importance to report this case to the scientific community.     

A comparison of 3H-cocaine binding on melanin granules and human hair in vitro

The in vitro experiments on the interaction of ³H-cocaine and melanin from Sepia officinalis confirmed the existence of drug binding sites on melanin granules. The results suggested that the binding of ³H-cocaine to melanin could be analyzed by assuming that the binding to the surface of pigment granules is analogous to the adsorption of a drug on a solid and follows Langmuir adsorption isotherm type I. Scatchard analysis indicated heterogeneity of binding sites. Structural and chemical alterations caused by isolation of the melanoproteins, which are heterogenous in nature and show different physicochemical properties, are considered to be most crucial. The studies on hair samples confirmed that melanin-drug interactions occur on the surface of melanin granules. These seem to be of minor importance compared to the drug-melanoprotein loading during melanogenesis for the observed influence of pigmentation on the drug content of hair fibers. From the results it was concluded that in vitro studies on melanin provide limited information and even drug-soaked hair must be regarded as inappropriate for the study of melanin-drug-binding in hair. Received: 21 August 1996 / Received in revised form: 4 December 1996     

Influence of the cosmetic treatment of hair on drug testing

An important issue of concern for drug analysis in hair is the change in the drug concentration induced by the cosmetic treatment of hair. The products used for this treatment are strong bases and they are expected to cause hair damage. As a result drugs may be lost from the hair matrix or, under conditions of environmental contamination, be more easily incorporated into the hair matrix. We investigated the effects of cosmetic treatment in vivo by analysing hair samples selected from people who had treated their hair by bleaching or dyeing before sample collection. All of the subjects admitted a similar drug consumption during the time period for which the strands were analysed. Samples were viewed under a microscope to establish the degree of hair damage. Treated and untreated portions from each lock of hair were then selected, separated and analysed by standard detection procedures for cocaine, opiates, cannabinoids and nicotine. In all cases the drug content in hair that had undergone cosmetic treatment decreased in comparison to untreated hair. The majority of the mean differences were in the range of 40%-60% (cocaine, benzoylecgonine, codeine, 6-acetylmorphine and THC-COOH). For morphine the mean difference was higher than 60%, and two cases (THC and nicotine) differed by approx. 30%. These differences depended not only on the type of cosmetic treatment, as bleaching produced higher decreases than dyeing, but also on the degree of hair damage i.e. the more damaged the hair, the larger the differences in the concentration levels of drugs. Received: 15 January 1996 / Received in revised form: 23 January 1997     

Death of a female addict due to heroin and cocaine overdoses: a case report with multiparameter evaluation

This study undertook a multiparameter evaluation of the death of a 21-year-old woman known to be an abuser of heroin and cocaine. The toxicological analysis of multiple postmortem specimens such as blood and hair was carried out using liquid chromatography atmospheric pressure chemical ionization tandem mass spectrometry (LC-APCI-MS-MS). The blood specimens of the deceased showed the presence of opium components such as morphine and its glucuronides together with cocaine and benzoylecgonine. The detected xenobiotic levels probably explained the cause of her death resulting from combined action of unintentional illicit drug overdose. By analysis of four 2-cm long hair segments, a heroin-cocaine addiction for at least 8 months antemortem was able to be documented; the presence of 6-monoacetylmorphine (6-MAM), cocaine, and benzoylecgonine was demonstrated. The histopathological findings of lesions of the internal organs of the deceased were consistent with long heroin and cocaine abuse. The use of multiple parameters, such as blood and hair segments as matrices and drug metabolites such as 6-MAM, morphine, glucuronides, and benzoylecgonine as target compounds, gave a well-defined outline of her death.     

Dose–hair concentration relationship and pigmentation effects in patients on low-dose clozapine

Several hair components have been suggested as possible molecular sites for drug binding and interaction. Of these, keratin and melanin have been investigated in some detail in order to assess the mechanisms by which the binding occurs. Substances that are positively charged at physiological pH may interact by electrostatic forces between their cationic groups and the anionic carboxylic groups on the surface of the melanin polymer. Studies in human subjects with grey hair have shown that various drugs are detectable in both the coloured (melanin rich) and white (melanin free) hair shafts of these individuals. Again this supports the proposition that keratin and hair proteins play an important role in the binding of drugs in hair. However, drugs are often found in significantly higher concentrations in pigmented hair strands than in senile white hair strands. Another interesting question is if the concentration measured in hair reflects the dose taken. Previous reports have both verified and rejected this hypothesis, but most agree that many factors have impact on the incorporation rate, melanin being one. In this study we obtained blood and hair samples from 12 grey haired patients treated with low-dose clozapine as an adjunct medication in their treatment against Parkinson disease. Each patient’s hair was divided into a pigmented and a non-pigmented portion and those were analyzed separately. Clozapine and desmethylclozapine were analyzed with LC-MS-MS after extraction of the analytes from hair and plasma. Paired results from the analysis of pigmented and white hair confirmed the preference for binding to pigmented hair for both clozapine and its metabolite. A majority of the incorporated clozapine was found in the pigmented hair but, as drugs could be detected in white hair, binding to hair protein or association with other hair matrix account for a significant part of drug accumulation in hair. High correlations between dose and the measured concentration of analyte were found for both clozapine (r = 0.91) and desmethylclozapine (r = 0.88). The data were presented at the Hair Testing Meeting, Vadstena, Sweden, May 2006. We hereby state that we do not have a significant financial interest or other relationship with any product manufacturer or provider of services discussed in this article.     

Drug-related deaths with evidences of body packing: Two case reports and medico-legal issues

Body packing is a general term used to indicate the internal transportation of drug packages, mainly cocaine, heroin, amphetamines, and methamphetamine, within the gastrointestinal tract. We described two cases of accidental drug intoxication, observed over the last year period, with evidence of intracorporeal drug concealment. The first case concerned a body packer transporting 69 drug packages of heroin adulterated with piracetam. The second body packer transported 16 drug packages of cocaine adulterated with levamisole. For both cases, forensic examination and toxicological analysis of drug packages and biological samples were carried out. Authors also wants to highlight the main medico-legal issues that commonly arise in cases of suspected or ascertained body packers.     

Toxicological detection of pholcodine and its metabolites in urine and hair using radio immunoassay,fluorescence polarisation immunoassay,enzyme immunoassay and gas chromatography-mass spectrometry

Summary Pholcodine (3-O-(2-morpholinoethyl)-morphine) is used in many countries as an antitussive without analgesic or addictive properties. It is of forensic relevance that pholcodine interferes with opiate immunoassays. In this paper a gas chromatographic-mass spectrometric (GC-MS) procedure for the precise and sensitive detection of pholcodine and its metabolites in urine and hair, after acid hydrolysis, extraction and acetylation, is presented. Furthermore, detection of pholcodine using radio immunoassay (RIA), fluorescence polarisation immunoassay (FPIA) and enzyme immunoassay (EIA) for opiates is described. Using GC-MS, unmodified pholcodine could be detected in urine samples 4–7 weeks after ingestion of a single therapeutic dose of 50 mg of pholcodine, the desmorpholinohydroxy metabolite for 1–2 weeks and the other metabolites (nor-, nordesmorpholinohydroxy-, hydroxy-, oxo- and noroxo-pholcodine) only during the first few hours. Morphine could also be detected in urine samples for the first few days. It was however mainly formed artificially during acid hydrolysis and only in trace amounts by metabolism. All the immunoassays tested gave positive results in urine samples during the first week taking the cut-off values recommended by the manufacturer into consideration. If values between the cut-off and the detection limit were taken into consideration, RIA and FPIA gave positive results for 2–4 weeks and EIA up to 2 weeks. Pholcodine could also be detected by RIA and GC-MS in samples of head hair clipped 10 weeks after ingestion of 50 mg and in daily shaved samples of beard hair over a period of three weeks after ingestion of three doses of 60 mg. It can be concluded that the widely used immunoassays for opiates show positive results in urine and hair samples for a long time after ingestion of the non-opioid pholcodine and that these results can be confirmed by the GC-MS procedure described in this paper.     

Concentrations of Δ9-tetrahydrocannabinol,cocaine and 6-monoacetylmorphine in hair of drug abusers

Hair samples taken from 850 individuals with presumed drug abuse were tested simultaneously forΔ⁹tetrahydrocannabinol (THC), cocaine, heroin, the primary heroin metabolite 6-monoacetylmorphine (6-MAM) and morphine. The drugs were extracted with methanol under sonication. Compared to other extraction procedures this solvent extraction technique provides high extraction yields and less experimental effort. The analyses were carried out using gas chromatography - mass spectrometry (GCMS) in selected ion monitoring (SIM) mode. This procedure allows the simultaneous detection of amphetamine, methylenedioxyamphetamine (MDA), methylenedioxymetbamphetamine (MDMA) and methylenedioxyethylamphetamine (MDE). THC was found in 104 (12.2%), cocaine in 230 (27%) and 6-MAM in 141 (16.6%) samples. In addition to 6-MAM, morphine was detected in 87 (10.2%) and heroin in 38 samples (4.5%). The concentrations found were in a range 0.009-16.7 ng/mg for THC, 0.037-129.68 ng/mg for cocaine, 0.028-79.82 ng/mg for 6-MAM, 0.045-53.14 ng/mg for heroin and 0.011-7.800 ng/mg for morphine. The statistical distribution of the drug concentrations compared with the self-reported consumption behaviour of the users may possibly lead to a better understanding of the relationship between drug dosage and corresponding concentrations in hair.     

A discourse on human hair fibers and reflections on the conservation of drug molecules

A gross discourse on human hair fibers and their formation is presented stressing the various interdisciplinary aspects, such as the morphological, biological, structural and biochemical data considered to be important in the field of hair analysis. An attempt is made to explain the incorporation of drug molecules during hair fiber formation by using the classical concepts of drug absorption based on lipoid theory and the pH-partition hypothesis as well as a modern biological approach on the permeability of cell membranes. In addition to the physicochemical considerations of the transport properties of a particular drug molecule such as a) the lipophilicity, which determines permeability through the membrane, b) the pKa value, c) the plasma protein binding and d) the molecular size and shape of the drug molecule, drug absorption is thought to be limited by the surface area and the residence time in the hair bulb. The thermodynamic approach according to the Kedem-Katchalsky equations seems even more satisfying. When the principles of biological transport across cell membranes are applied to the cell populations present in the hair root, a hypothesis of extracellular and intracellular drug localizations results. It is speculated that the cell membrane complex (CMC) and the melanin granules present the main sources of incorporated drug molecules within the keratinized hair fibers.     

Detection of drugs in human hair for clinical and forensic applications

Summary While hair has for sometime been analyzed for assessment of trace elements, it is only in recent years that attention has been focused on this matrix as a possible means of evaluating drug impregnation. This technique was applied to treated subjects and drug abusers for determination of drug consummation. The method involved decontamination in ethanol, solubilization in sodium hydroxide at 100°C for 10 min, extraction in chloroform/isopropanol/n-heptane (50:17:33, v/v), separation on a BP-5 capillary column (GC) and detection by mass spectrometry. Hair samples were analysed for barbiturates, antidepressants, benzodiazepines, -blockers, nicotine, opiates, benzoylecgonine, cannabis and amphetamines.     

Interpretation of forensic cases based on empirical data

Over the course of the last years the importance of hair analysis increased obviously. For example work place testing, driving licence cases, so-called health checks, and especially in criminal acts the analysis of illicit substances is common. With the modern multiplex analytical methods (GC/MS, GC/MS/MS, LC/MS) the routine analytical probe of hair is in general unproblematic. But one of the major problems in hair analysis is the interpretation of the results. To solve this difficult and challenging task statistical data as a source of information could be a helpful tool. Examination of more than 1,000 hair segments within the past 2 years using gas chromatography/tandem-mass spectrometry (GC/MS/MS) as the preferred method for conducting the daily routine detection of the most prevalently abused drugs and metabolites, such as cannabinoids, cocaine, some synthetic drugs from the amphetamine group, and opiates serve as the basis for the statistics. The quantity of analytical results and additional essential facts have been documented in the publication to present our sources of information and supplementary data to prepare forensic reports. We hereby state that we do not have a significant financial interest or other relationship with any product manufacturer or provider of services discussed in this article.     

Bringing colour back after 70 years: Predicting eye and hair colour from skeletal remains of World War II victims using the HIrisPlex system

Retrieving information about externally visible characteristics from DNA can provide investigative leads to find unknown perpetrators, and can also help in disaster victim and other missing person identification cases. Aiming for the application to both types of forensic casework, we previously developed and forensically validated the HIrisPlex test system enabling parallel DNA prediction of eye and hair colour. Although a recent proof-of-principle study demonstrated the general suitability of the HIrisPlex system for successfully analysing DNA from bones and teeth of various storage times and conditions, practical case applications to human remains are scarce. In this study, we applied the HIrisPlex system to 49 DNA samples obtained from bones or teeth of World War II victims excavated at six sites, mostly mass graves, in Slovenia. PCR-based DNA quantification ranged from 4 pg/μl to 313 pg/μl and on an average was 41 pg/μl across all samples. All 49 samples generated complete HIrisPlex profiles with the exception of one MC1R DNA marker (N29insA) missing in 83.7% of the samples. In 44 of the 49 samples (89.8%) complete 15-loci autosomal STR (plus amelogenin) profiles were obtained. Of 5 pairs of skeletal remains for which STR profiling suggested an origin in the same individuals, respectively, 4 showed the same HIrisPlex profiles and predicted eye and hair colours, respectively, while discrepancies in one pair (sample 26 and 43) are likely to be explained by DNA quantity and quality issues observed in sample 43. Sample 43 had the lowest DNA concentration of only 4 pg/μl, producing least reliable STR results and could be misleading in concluding that samples 43 and 26 originate from the same individual. The HIrisPlex-predicted eye and hair colours from two skeletal samples, suggested to derive from two brothers via STR profiling together with a living sister, were confirmed by the living sister's report. Overall, we demonstrate that after more than 70 years, HIrisPlex-based eye and hair colour prediction from skeletal remains is feasible with high success rate. Our results further encourage the use of the HIrisPlex system in missing person/disaster victim identification to aid the identification process in cases where ante-mortem samples or putative relatives are not directly available, and DNA predicted eye and hair colour information provides leads for locating them, allowing STRbased individual identification.     

Developmental validation of the HIrisPlex system: DNA-based eye and hair colour prediction for forensic and anthropological usage

Forensic DNA Phenotyping or ‘DNA intelligence’ tools are expected to aid police investigations and find unknown individuals by providing information on externally visible characteristics of unknown suspects, perpetrators and missing persons from biological samples. This is especially useful in cases where conventional DNA profiling or other means remain non-informative. Recently, we introduced the HIrisPlex system, capable of predicting both eye and hair colour from DNA. In the present developmental validation study, we demonstrate that the HIrisPlex assay performs in full agreement with the Scientific Working Group on DNA Analysis Methods (SWGDAM) guidelines providing an essential prerequisite for future HIrisPlex applications to forensic casework. The HIrisPlex assay produces complete profiles down to only 63 pg of DNA. Species testing revealed human specificity for a complete HIrisPlex profile, while only non-human primates showed the closest full profile at 20 out of the 24 DNA markers, in all animals tested. Rigorous testing of simulated forensic casework samples such as blood, semen, saliva stains, hairs with roots as well as extremely low quantity touch (trace) DNA samples, produced complete profiles in 88% of cases. Concordance testing performed between five independent forensic laboratories displayed consistent reproducible results on varying types of DNA samples. Due to its design, the assay caters for degraded samples, underlined here by results from artificially degraded DNA and from simulated casework samples of degraded DNA. This aspect was also demonstrated previously on DNA samples from human remains up to several hundreds of years old. With this paper, we also introduce enhanced eye and hair colour prediction models based on enlarged underlying databases of HIrisPlex genotypes and eye/hair colour phenotypes (eye colour: N = 9188 and hair colour: N = 1601). Furthermore, we present an online web-based system for individual eye and hair colour prediction from full and partial HIrisPlex DNA profiles. By demonstrating that the HIrisPlex assay is fully compatible with the SWGDAM guidelines, we provide the first forensically validated DNA test system for parallel eye and hair colour prediction now available to forensic laboratories for immediate casework application, including missing person cases. Given the robustness and sensitivity described here and in previous work, the HIrisPlex system is also suitable for analysing old and ancient DNA in anthropological and evolutionary studies.     

Insulin murder and the case of Colin Norris

Although insulin is an essential medicine and a life-saving drug, it has also been incriminated in many poisoning deaths; accidental, suicidal and some with malicious intent. Overdosing with insulin precipitates a life-threatening state of hypoglycemia and if untreated leads to coma, irreversible brain damage and death. Normally, the pancreatic β-cells secrete equimolar amounts of insulin and C-peptide into the portal venous blood, although under physiological conditions the plasma concentration ratio (insulin/C-peptide) is less than unity, because insulin is more susceptible to hepatic first-pass metabolism. A high ratio of insulin/C-peptide in plasma from a poisoned patient is compelling evidence that pharmaceutical insulin was administered, which does not contain C-peptide. The analysis of insulin and C-peptide was traditionally done by immunoassay methods (RIA and/or ELISA), although high resolution LC-MS/MS is more suitable for forensic purposes and permits the identification of insulin analogues. Use of insulin as a murder weapon is exemplified by the case of Colin Norris, a male nurse found guilty of murdering four elderly patients and the attempted murder of a fifth by injecting them with insulin. However, the prosecution evidence against Norris was mainly circumstantial and hearsay. Toxicological evidence against Norris consisted of a high insulin/C-peptide concentration ratio in plasma from one of the victims. This analysis was done by an immunoassay method at a clinical laboratory and not a forensic laboratory. Analytical procedures, including chain-of-custody routines, are more stringent at forensic laboratories. Since his conviction, some of the medical evidence against Norris has been called into question, especially the prevalence of spontaneous attacks of hypoglycemia in elderly and frail patients with co-morbidities.     

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

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.