Unknown Genotype Research Articles

Genetic variability of Blastocystis hominis isolates in China

To determine if genetic diversity of Blastocystis hominis exists in China, 35 B. hominis isolates obtained from 19 asymptomatic infected individuals and 16 patients with gastrointestinal symptoms were genotyped by PCR using seven pairs of known sequenced-tagged site (STS) primers. Out of the 35 isolates, 29 were identified as one of the known genotypes, while five isolates showed two distinct genotypes, and one isolate was an unknown genotype as this was negative with all the STS primers. In this study, none of the isolates was classified as subtypes 4-7. Compared with the spectrum of human B. hominis subtypes obtained from five geographically different countries (Japan, Pakistan, Bangladesh, Germany, and Thailand), these results showed that subtype 1 was more a popular genotype (18/35) in China. In addition, two groups of the isolates from 19 asymptomatic infected individuals and those from 16 patients with intestinal symptoms were compared with the PCR-based subtype classification. The results suggest a possible relationship between subtype 1 and a pathogenic potential of this parasite.

Humans as Reservoir for Enterotoxin Gene–carryingClostridium perfringensType A

We found a prevalence of 18% for enterotoxin gene-carrying (cpe+) Clostridium perfringens in the feces of healthy food handlers by PCR and isolated the organism from 11 of 23 PCR-positive persons by using hydrophobic grid membrane filter-colony hybridization. Several different cpe genotypes were recovered. The prevalence was 3.7% for plasmidial IS1151-cpe, 2.9% for plasmidial IS1470-like-cpe, 0.7% for chromosomal IS1470-cpe, and 1.5% for unknown cpe genotype. Lateral spread of cpe between C. perfringens strains was evident because strains from the same person carried IS1470-like cpe but shared no genetic relatedness according to pulsed-field gel electrophoresis analysis. Our findings suggest that healthy humans serve as a rich reservoir for cpe+ C. perfringens type A and may play a role in the etiology of gastrointestinal diseases caused by this organism. The results also indicate that humans should be considered a risk factor for spread of C. perfringens type A food poisoning and that they are a possible source of contamination for C. perfringens type A food poisoning.

The congenital long QT syndromes from genotype to phenotype: clinical implications

The long QT syndrome (LQTS) is a genetic disorder responsible for many sudden deaths before age 20. The identification of several LQTS genes, all encoding cardiac ion channels, has had a major impact on the management strategy for both patients and family members. Genotype-guided therapy allows more effective individually tailored therapy. Therapeutic options, including beta-blockers, left cardiac sympathetic denervation, and implantable defibrillators are discussed for patients of known and of unknown genotype. The recent identification of modifier genes which amplify the effect of an LQTS mutation may change the approach to risk stratification.

Technical validation of a multiplex platform to detect thirty mutations in eight genetic diseases prevalent in individuals of Ashkenazi Jewish descent

Purpose:This study determines the analytic accuracy of a Luminex bead-based commercial analyte-specific reagent for the simultaneous analysis of 30 mutations prevalent in Ashkenazi Jews at eight genetic disease loci. MethodsDNA from 20 samples with known abnormal genotypes were run a total of 109 times. DNA from 820 patients with unknown genotypes submitted for Ashkenazi Jewish testing panels were analyzed using our current laboratory techniques. The 820 samples were then stripped of identifiers, coded, and reanalyzed using the Tm Biosciences (Toronto, Canada) Ashkenazi Jewish panel analyte-specific reagent in a blinded fashion. For the controls, comparisons were made with their known genotypes. For the patient samples, the results of the Tm assay were compared with the results of our current assay. For 24 of the 30 mutations, we had genomic DNA controls or detected patients' samples heterozygous for these mutations. ResultsThere were no discrepant results in the control or patient samples. In the patient samples, 19,680 genotyping reactions were performed without error in both our laboratory-developed single-disease assays and the Tm multiplex assay. Including the controls, 22,296 genotypes were determined without error. ConclusionThe Tm Biosciences Ashkenazi Jewish analyte-specific reagent is capable of performing accurate analyses of 24 different mutations in eight different genes in a single multiplex reaction and can be used with confidence in the clinical molecular genetics laboratory.

Burst bicycle exercise facilitates diagnosis of latent long QT syndrome

The aim of this study was to develop a diagnostic technique to detect latent long QT syndrome. Asymptomatic patients with genetically diagnosed long QT syndrome (LQTS) may have a normal resting QT interval, yet remain at risk for cardiac events. We hypothesized that the QT response during a novel burst exercise protocol simulating clinical events might distinguish patients with "latent LQTS" from healthy subjects. A burst bicycle protocol was performed on 31 healthy subjects and 31 patients with LQTS (13 LQT2, 3 LQT1, 15 unknown genotype). The bicycle exercise protocol involved sudden maximal exertion against a fixed workload (200 W) for 1 minute. Digitized 12-lead eletrocardiograms were acquired every 10 seconds at baseline for 1 minute, during 1 minute of burst exercise, and for 5 minutes during recovery. Patients with LQTS were segregated according to whether the baseline QTc was normal (< or = 440 milliseconds, n = 13) or abnormal (> 440 milliseconds, n = 18). During exercise, the QTc increased to a greater extent in the group with latent LQTS (DeltaQTc 98 +/- 36 milliseconds) in comparison with controls (DeltaQTc 65 +/- 19 milliseconds, P < .01) and those with baseline QTc prolongation (DeltaQTc 17 +/- 70 milliseconds, P < .01). In patients with a normal baseline QTc, a DeltaQTc > 85 milliseconds had a sensitivity of 85% and a specificity of 86% for LQTS (P = .0004). Marked QTc prolongation during burst bicycle ergometry provides potentially diagnostic information for patients with normal baseline QTc and suspected LQTS.

Electrophysiologic differentiation of homozygous and heterozygous Abyssinian-crossbred cats with late-onset hereditary retinal degeneration

To develop a method to electrophysiologically differentiate heterozygous-carrier Abyssinian-crossbred cats from homozygous-affected Abyssinian-crossbred cats before clinical onset of inherited rod-cone retinal degeneration. 14 back-crossed Abyssinian-crossbred cats of unknown genotype (homozygous or heterozygous) for inherited rod-cone retinal degeneration, 24 age-matched mixed-breed control cats, 6 age-matched heterozygous Abyssinian-crossbred cats, and 6 homozygous Abyssinian cats. Electroretinography (ERG) of heterozygous and homozygous cats revealed differences, especially for scotopic recordings. Frequent ophthalmoscopy and ERG (2 to 5 times; at intervals of 3 to 6 months) of back-crossed cats were performed. Amplitudes and implicit times were analyzed by use of a graphic representation of results. Ratios for amplitudes of the b-waves to amplitudes of the a-waves (b-wave:a-wave) were compared. 8 back-crossed cats had decreased a-wave amplitudes, increased b-wave implicit times, and abnormal ERG waveforms. Values for the b-wave:a-wave for the highest scotopic light intensity were significantly higher for those same 8 cats. The 8 back-crossed Abyssinian-crossbred cats with abnormal results developed fundus changes over time consistent with disease. A graphic representation of ERG results can be used to differentiate between genotypes prior to funduscopic changes. Values for the b-wave:a-wave ratio provide confirmation. These ERG analyses may be applied clinically in the diagnosis of retinal degenerations in various species. Cats with hereditary rod-cone degeneration may be a useful model for comparative studies in relation to retinitis pigmentosa in humans. Similar evaluations of ERG results could possibly be used for humans with suspected generalized retinal degeneration.

Denaturing HPLC-based approach for detection of COL7A1 gene mutations causing dystrophic epidermolysis bullosa

Dystrophic epidermolysis bullosa (DEB) is a rare clinically heterogeneous genodermatosis due to genetic defects in type VII collagen gene ( COL7A1). Identification of COL7A1 mutations is a challenge since this gene comprises 118 exons and more than 300 mutations scattered over the gene have been reported. Here, we describe for the first time the use of denaturing high performance liquid chromatography (DHPLC) for COL7A1 mutation detection. To validate the method, exon-specific DHPLC conditions were applied to screen DNA samples from patients carrying known COL7A1 mutations. Abnormal DHPLC profiles were obtained for all known mutations. Subsequent DHPLC analysis of 17 DEB families of unknown genotype allowed the identification of 21 distinct mutations, 9 of which were novel. The DHPLC mutation detection rate was significantly higher compared with our mutation scanning rate with conventional techniques (97% vs 86%), indicating DHPLC as the method of choice for COL7A1 molecular characterization in DEB patients.

A new method for identifying informative genetic markers in selectively bred rats

Microsatellite length polymorphisms are useful for the mapping of heritable traits in rats. Over 4000 such microsatellites have been characterized for 48 inbred rat strains and used successfully to map phenotypes that differ between strains. At present, however, it is difficult to use this microsatellite database for mapping phenotypes in selectively bred rats of unknown genotype derived from outbred populations because it is not immediately obvious which markers might differ between strains and be informative. We predicted that markers represented by many alleles among the known inbred rat strains would also be most likely to differ between selectively bred strains derived from outbred populations. Here we describe the development and successful application of a new genotyping tool (HUMMER) that assigns "heterozygosity" (Het) and "uncertainty" (Unc) scores to each microsatellite marker that corresponds to its degree of heterozygosity among the 48 genotyped inbred strains. We tested the efficiency of HUMMER on two rat strains that were selectively bred from an outbred Sprague-Dawley stock for either high or low activity in the forced swim test (SwHi rats and SwLo rats, respectively). We found that the markers with high Het and Unc scores allowed the efficient selection of markers that differed between SwHi and SwLo rats, while markers with low Het and Unc scores typically identified markers that did not differ between strains. Thus, picking markers based on Het and Unc scores is a valuable method for identifying informative microsatellite markers in selectively bred rodent strains derived from outbred populations.

A new HLA-DRB1 genotyping method using single nucleotide polymorphism (SNP) analysis with multiplex primer extension reactions and its application to mixed samples.

We have improved on conventional methods for HLA-DRB1 genotyping and devised a new method that is simple, cost-effective, and adequately applicable to routine forensic practice. This method consists of group-specific polymerase chain reaction (PCR) of the exon 2 region of the HLA-DRB1 gene and simultaneous detection of single nucleotide polymorphisms (SNPs) at multiple sites using multiplex primer extension reactions. With this method, we successfully detected HLA-DRB1 genotypes from the following materials: the peripheral blood of 142 donors, 6 aged saliva stains of known DRB1 genotype stored for 5-10 years at room temperature, 10 aged bloodstains of unknown DRB1 genotype stored for 29 years at room temperature, and minimal bloodstains and saliva stains from 3 donors of known DRB1 genotypes. Furthermore, we were able to type DRB1 alleles of the minor component in mixed samples at a proportion of 1/1,000 or 1/10,000. In a criminal case, DRB1 alleles detected from mixed bloodstains on a sword found at the scene enabled us to explain the case. This method is expected to be useful for forensic medicine.

Replication of Autism Linkage: Fine-Mapping Peak at 17q21

Autism is a heritable but genetically complex disorder characterized by deficits in language and in reciprocal social interactions, combined with repetitive and stereotypic behaviors. As with many genetically complex disorders, numerous genome scans reveal inconsistent results. A genome scan of 345 families from the Autism Genetic Resource Exchange (AGRE) (AGRE_1), gave the strongest evidence of linkage at 17q11-17q21 in families with no affected females. Here, we report a full-genome scan of an independent sample of 91 AGRE families with 109 affected sibling pairs (AGRE_2) that also shows the strongest evidence of linkage to 17q11-17q21 in families with no affected females. Taken together, these samples provide a replication of linkage to this chromosome region that is, to our knowledge, the first such replication in autism. Fine mapping at 2-centimorgan (cM) intervals in the combined sample of families with no affected females reveals a linkage peak at 66.85 cM, which places this locus at 17q21.

Genetic substructure of the Spanish Manchega sheep breed

The Manchega sheep breed is an autochthonous dairy breed of Spain, which has two colour varieties, the white and the black. There are only a few herds of black animals, and as a result, this variety is considered in Spain to be a special protected endangered breed, receiving funds for its conservation. Genetic variability at 15 microsatellite loci and two mutations at MC1-R locus was analysed at three different hierarchic levels in the data of the Manchega Spanish sheep breed: (1) the breed itself, i.e. the whole data set without division into colour varieties and flocks; (2) the two colour varieties; and (3) five flocks (three blacks and two whites). Allele frequencies and heterozygosity revealed high genetic variation in the black variety despite its small population size. Noticeably, the Black3 population showed the wild-type allele for the MC1-R locus related to white colour at a significant frequency of 0.208. The degree of population subdivision calculated between varieties and populations from F ST indices was around 4% of the total variability. The allele frequencies estimated were used to assign an unknown genotype of an individual to the colour variety population or flock (using their genotype frequencies as a reference) with a high degree of accuracy (99% by the Bayesian method using six microsatellites in variety assignment). In this way, although Black3 animals are black in phenotype, this population is near to the white population in genotype, because only 16.6% were assigned to the black variety. Values of D Reynolds (0.038) and D m (0.092) genetic distances indicated a clear differentiation between the two varieties. D Reynolds distance between flock pairs revealed that White1/White2 and Black1/Black2 populations are very close, while Black3 is closer to the white populations. In conclusion, Manchega sheep breed colour varieties show good diversity measures that can permit a higher selection pressure without increasing inbreeding related to the whole population ( F IT = 0.045) and within population ( F IS = 0.009). Furthermore, results of heterozygosities, individual assignment test, and distance values indicate a crossbreeding of Black3 and White animals. As a result, some of the Black3 animals are not suitable for use in the conservation-breeding program of the black variety.

Inheritance of the Two-points Pattern of Partly Colored Seedcoats in Common Bean

Common bean (Phaseolus vulgaris L.) seedcoats can have partly colored patterns such as the new two-points pattern, which has an unknown genotype. The gene tcf (derived from PI 507984) expresses partly colored seedcoat pattern with colored flowers. A genetic tester stock tcf two-points BC3 5-593 was derived from PI 507984 by backcrossing to the recurrent parent, Florida dry bean breeding line 5-593, which has black self-colored seeds and purple flowers due to the genotype T P V. A series of test crosses were made between tcf two-points BC3 5-593 and three genetic tester stocks: t z jers white BC3 5-593, t z bip bipunctata BC3 5-593, and t z virgarcus BC3 5-593. All three test crosses were studied in F1 and F2 populations, and the latter test cross in F3 progenies derived from 80 randomly selected F2 plants. The two-points pattern was never observed with white flower plants expressed by t/t, supporting the hypothesis that tcf is necessary for two-points expression. The complete genotype for two-points was found to be tcf z jers. The tcf gene expresses more extensive colored zones in partly colored seedcoats than t. For example, tcf z J expresses self-colored seedcoats, whereas tcf/t z J expresses white ends pattern and t z J expresses virgarcus. Similarly, the tcf z jers genotype expresses two-points pattern, whereas t z jers expresses white seedcoat; and tcf/-z J/jers expresses PI type pattern, whereas t z J/jers expresses weak virgarcus pattern.

Estudio comparativo de dos modelos que utilizan parámetros bioquímicos en el diagnóstico no invasivo de la fibrosis hepática en pacientes con hepatitis C

Several models for the prediction of liver fibrosis have been developed which consist of the measurement of routine laboratory data: a) a model combining platelets, gamma-glutamil-transpeptidase, cholesterol and age (Forns model), and b) a model using an aspartate-aminotransferase to platelet ratio index (APRI). Our study was aimed to compare both non-invasive methods to predict mild fibrosis (F0-F1) or to confirm advanced fibrosis (F3, F4) in patients with chronic hepatitis C.We included 199 patients with chronic hepatitis. The average age (standard deviation) was 41 (11) years (16-66), and there were 117 men and 82 women. We found a genotype 1 in 108 patients (54.2%), 45 had a non-1 genotype (22.6%), and 46 (23.1%) had an unknown genotype. Mild fibrosis stage (F0-F1) was found in 96 patients, F2 in 52 and advanced fibrosis (F3-F4) in 51 patients. We calculated the APRI and the Forns's index.Patients infected with genotype 1 were older (44 [11] vs 36 [4.3] years; p = 0.001), presented higher levels of cholesterol (179 [40] vs 160 [42] mg/dl; p = 0.05) and lower levels of alanine-aminotransferase (112 [86] vs 169 [87] IU/l; p = 0.03). The Forns's model predicted mild fibrosis (F0-F1) in 71.4% while the APRI model did it in 72.7%. The Forns's model confirmed advanced fibrosis in 78.6% against 54.2% from the APRI one. The predictive capacity in both models increased when analyzing patients with the genotype 1. Moreover, the predictive capacity of advanced fibrosis or exclusion of significant fibrosis reached more than 90% when both models were used together in patients with a genotype 1.Non-invasive methods for the prediction of liver fibrosis can be very useful in clinical practice, mainly in patients with genotype 1 when the two methods are used together.

Identification of Non- Helicobacter pylori Spiral Organisms in Gastric Samples from Humans, Dogs, and Cats

Tightly coiled bacteria are a rare cause of gastric pathology in humans and represent a mixture of species for which a zoonotic origin is suspected. Similar organisms are common inhabitants of the gastric mucosae of carnivores and pigs. It was the goal of the present study to determine the actual occurrence of each individual Helicobacter species in human, canine, and feline stomachs in order to better understand the possible zoonotic significance. Gastric biopsy samples from humans with histological evidence of non-Helicobacter pylori spiral bacteria (n = 123) and samples from the gastric antrum, corpus, and cardia from dogs (n = 110) and cats (n = 43) were subjected to a multiplex PCR, enabling the identification of Helicobacter felis, Helicobacter bizzozeronii, Helicobacter salomonis, and "Candidatus Helicobacter suis." A PCR for detecting H. pylori was applied to all human samples. Single infections with "Candidatus Helicobacter suis," H. felis, H. bizzozeronii, H. salomonis, a hitherto unknown genotype of a non-H. pylori spiral organism (Helicobacter-like organism 135 [HLO135]), and H. pylori were identified in 30.9%, 8.9%, 2.4%, 11.4%, 7.3%, and 8.9% of the human biopsy samples, respectively. Mixed infections (16.3%) with two or even three of these were also found. In the canine stomach, H. bizzozeronii (70.0%) was encountered as the main spiral organism, while H. felis (62.7%) and HLO135 (67.4%) were the predominant Helicobacter species found in the feline gastric mucosa. Although the majority of human non-H. pylori organisms are Helicobacter species naturally occurring in the stomachs of pigs, cats, and dogs, the frequent identification of H. salomonis in human gastric biopsy samples is in contrast to its rare identification in pet carnivore samples, urging us to suspect other sources of infection.

Polymorphism of prolamin proteins of the grain of triticale varieties certifiedin the Czech Republic

&amp;nbsp;Genetic diversity was detected in 11 varieties of triticale registered in the Czech Republic by means of polymorphism of prolamin proteins using the PAGE ISTA method. The polymorphism of prolamin proteins allowed the differentiation of the individual triticale varieties in 2002 and 2003 harvests. On the basis of Dice&amp;rsquo;s calculations of coefficients of similarity we discovered, in parallel with the uniform genotypes, genotypes with sister prolamin spectrums with a&amp;nbsp;different percentage of participation in the respective years. A uniform spectrum was detected in the following varieties: Disco, Kolor, Lamberto, Marko, Presto, Sekundo, Ticino and Tricolor; Kitaro and Modus were dimorphous varieties. In 2003 three sister prolamin lines appeared in the variety Gabo and in 2004 only two. In 2003 a 5% admixture of a foreign genotype was detected in the variety Marko. Typical of the unknown genotype was the gliadin block Gld&amp;nbsp;1B3, which is the marker of rye translocation T1BL.1RS, gene Sr31 with resistance to black rust, higher cold resistance and lower baking quality of the wheat. The prolamin proteins of triticale grain are suitable for the detection of the genetic diversity and for the assessment of varietal authenticity and purity in seed samples of triticale varieties registered in the Czech Republic.

Human Prenatal Nasal Bone Lengths: Normal Standards and Length Values in Fetuses with Cleft Lip and Cleft Palate

The aim of this study was to present prenatal autopsy standards for nasal bone length in normal fetuses, as well as to compare nasal bone lengths in human fetuses with cleft lip and palate with those standards. The material consisted of human fetuses investigated in connection with diagnosed and legally approved abortions and spontaneous abortions; 40 were normal and 26 had cleft lip and palate (7 isolated cleft lip, 12 isolated cleft palate, and 7 combined cleft lip and palate). Menstrual ages (MA) ranged from 12 to 25 weeks, crown-rump length (CRL) from 55 to 210 mm and foot length (FL) from 7 to 44 mm. All fetuses were radiographed in lateral projection, and, using these images, the nasal bone lengths were measured with a digital caliper. Regression analyses were performed. Standards for normal nasal bone length at different ages are expressed as menstrual age, crown-rump length, or foot length. Comparisons with normal standards showed that the isolated cleft lip group had a significantly smaller nasal bone length than the normal fetuses had. Fetuses with isolated cleft palate and fetuses with combined cleft lip and palate showed no significant deviation from normal standards. Normal nasal bone standards can contribute to information on deviations in nasal bone length for aborted fetuses with known and unknown genotypes. The differences in nasal bone lengths in fetuses with different lip and palate clefting can contribute to understanding the pathogenesis of cleft lip and palate.

Using genotype probabilities in survival analysis: a scrapie case

The objective was to evaluate the potential use of genotype probabilities to handle records of non-genotyped animals in the context of survival analysis. To do so, the risks associated with the PrP genotype and other transmission factors in relation to clinical scrapie were estimated. Data from 4049 Romanov sheep affected by natural scrapie were analyzed using survival analysis techniques. The original data set included 1310 animals with missing genotypes; five of those had uncensored records. Different missing genotype-information patterns were simulated for uncensored and censored records. Three strategies differing in the way genotype information was handled were tested. Firstly, records with unknown genotypes were discarded (P1); secondly, those records were grouped in an unknown class (P2). Finally the probabilities of genotypes were assigned (P3). Whatever the strategy, the ranking of relative risks for the most susceptible genotypes (VRQ-VRQ, ARQ-VRQ and ARQ-ARQ) was similar even when the non-genotyped animals were not a negligible part of uncensored records. However, P3 had a more efficient way of handling missing genotype information. As compared to P1, either P2 or P3 avoided discarding the records of non-genotyped animals; however, P3 eliminated the unknown class and the risk associated with this group. Genotype probabilities were shown to be a useful technique to handle records of individuals with unknown genotype.

Genetic relationships between diploid and allotetraploid cherry species (Prunus avium, Prunus x gondouinii and Prunus cerasus).

Prunus avium L. (diploid, AA, 2n=2x=16), Prunus cerasus L. (allotetraploid, AAFF, 2n=4x=32) species, and their hybrid Prunus x gondouinii Rehd., constitute the most widely cultivated cherry tree species. P. cerasus is supposed to be an hybrid species produced by the union of unreduced P. avium gametes and normal P. fruticosa gametes. A continuum of morphological traits between these three species makes their assignation difficult. The aim of this paper is to study the genetic relationships between tetraploid and diploid cherry species. In all, 114 genotypes belonging to these species were analyzed using 75 AFLP markers. The coordinates of these genotypes on the first axis of a correspondence analysis allowed us to clearly distinguish each species, to identify misclassifications and to assign unknown genotypes to one species. We showed that there are specific alleles in P. cerasus, which are not present in the A genome of P. avium and which probably come from the F genome of P. cerasus. The frequencies of each marker in the A and the F genomes were estimated in order to identify A and F specific markers. We discuss the utility of these specific markers for finding the origin of the A and F genomes in the allopolyploid species.

PCR-based identification of zoonotic isolates of Blastocystis from mammals and birds.

The genotype of Blastocystis isolated from humans and animals is highly polymorphic. Therefore, it is important to compare the genotypes of Blastocystis isolates from humans and animals to determine the zoonotic potential of animal isolates. PCR-based genotype classification using known sequence-tagged site (STS) primers allows identification of zoonotic isolates of animal origin. To this end, 51 isolates from monkeys, cattle, pigs, chickens, quails and pheasants were subjected to genotype analysis using seven kinds of STS primers. Out of the 51 isolates, 39 were identified as one of the known genotypes, four showed mixed genotypes, and eight were unknown genotypes as these were negative for all STS primers. When these results were combined with previous studies on 41 isolates from animals and compared with the diversity of genotypes of 102 human Blastocystis hominis isolates, 67.4 % (62/92) of isolates from mammals and birds were identical to human B. hominis genotypes. Since the unknown genotype of human origin had been placed into an additional clade in the small-subunit rRNA gene phylogeny, further molecular study on the eight isolates of unknown genotype from the present study will facilitate our understanding of their zoonotic potential.

Practical use of microsatellite markers to manage Vitis vinifera germplasm: Molecular identification of grapevine samples collected blindly in D.O. “El Bierzo” (Spain)

SummaryThe construction and utilization of a grapevine molecular database including the cultivars commonly grown in the “El Bierzo” region of Spain is described in this work. Five different microsatellite DNA sequences from 24 grape cultivars were amplified using PCR and capillary electrophoresis. The results obtained could be assembled in a data matrix that revealed no variability within cultivars and a high degree of variation between cultivars. The patterns obtained have allowed the unequivocal identification of all the grapevine varieties considered. To test the utility of this database to identify genotypes we analysed the microsatellite DNA profiles from 210 samples of unknown genotype blindly collected in “El Bierzo” (Spain). We were able to identify 98.6% of these samples. Our results strongly indicate that microsatellite markers, in coordination with ampelography, would provide an efficient way to arrange Spanish Vitis germplasm.