MuStaR and other software for locus-specific mutation databases

Methylome and transcriptome analysis of flowering branches building of Citrus plants induced by drought stress

Citrus plants exhibit positive floral response under water stress conditions, however, the mechanistic understanding of floral induction remains largely unexplored in water deficit. In this study, DNA methylomic and transcriptomic analyses were integrated to explore the flowering bud formation as well as branches building after light drought stress. While comparing with the conventional watering group (CK), the light drought group treated with five months (LD) showed a significant increase in the flowering branches, whereas an apparent decrease in vegetative branches. Global DNA methylation analysis showed that the LD Group acquired DNA methylation in more than 70090 genomic regions and lost DNA methylation in about 18421 genomic regions compared with normal watering group, this indicates that water deficiency leads to a global increase in the expression of DNA methylation in citrus. In the same time, we verified that the increase of DNA methylation level in LD group was correlated with the decrease of DNA demethylase related gene expression. Interestingly, in transcription analysis, it was found that the promoting flower genes of the LD group did not increase but decreased similarly with repressing genes, which is contrary to the intended result. Thus, we thought the lower expression of suppressors FLC and BFT were the key influencing factor to stimulate the flowering branches formation after LD treatment. Moreover, there was a strong negative correlation between the genes expression level and methylation level of the flowering induction/flower development genes. In general, we thought high global DNA methylation level induced by water deficit regulate the flowering branches building by reducing FLC and BFT genes expression.

Human variation databases

More than 100 000 human genetic variations have been described in various genes that are associated with a wide variety of diseases. Such data provides invaluable information for both clinical medicine and basic science. A number of locus-specific databases have been developed to exploit this huge amount of data. However, the scope, format and content of these databases differ strongly and as no standard for variation databases has yet been adopted, the way data is presented varies enormously. This review aims to give an overview of current resources for human variation data in public and commercial resources.

COMUS: Clinician-Oriented locus-specific MUtation detection and deposition System

Background

A disease-causing mutation refers to a heritable genetic change that is associated with a specific phenotype (disease). The detection of a mutation from a patient's sample is critical for the diagnosis, treatment, and prognosis of the disease. There are numerous databases and applications with which to archive mutation data. However, none of them have been implemented with any automated bioinformatics tools for mutation detection and analysis starting from raw data materials from patients. We present a Locus Specific mutation DB (LSDB) construction system that supports both mutation detection and deposition in one package.

Results

COMUS (Clinician-Oriented locus specific MUtation detection and deposition System) is a mutation detection and deposition system for developing specific LSDBs. COMUS contains 1) a DNA sequence mutation analysis method for clinicians' mutation data identification and deposition and 2) a curation system for variation detection from clinicians' input data. To embody the COMUS system and to validate its clinical utility, we have chosen the disease hemophilia as a test database. A set of data files from bench experiments and clinical information from hemophilia patients were tested on the LSDB, KoHemGene http://www.kohemgene.org, which has proven to be a clinician-friendly interface for mutation detection and deposition.

Conclusion

COMUS is a bioinformatics system for detecting and depositing new mutations from patient DNA with a clinician-friendly interface. LSDBs made using COMUS will promote the clinical utility of LSDBs. COMUS is available at http://www.comus.info.

A1ATVar: a relational database of human SERPINA1 gene variants leading to alpha1-antitrypsin deficiency and application of the VariVis software

We have developed a relational database of human SERPINA1 gene mutations, leading to alpha(1)-antitrypsin (AAT) deficiency, called A(1)ATVar, which can be accessed over the World Wide Web at www.goldenhelix.org/A1ATVar. Extensive information has been extracted from the literature and converted into a searchable database, including genotype information, clinical phenotype, allelic frequencies for the commonest AAT variant alleles, methods of detection, and references. Mutation summaries are automatically displayed and user-generated queries can be formulated based on fields in the database. A separate module, linked to the FINDbase database for frequencies of inherited disorders allows the user to access allele frequency information for the three most frequent AAT alleles, namely PiM, PiS, and PiZ. The available experimental protocols to detect AAT variant alleles at the protein and DNA levels have been archived in a searchable format. A visualization tool, called VariVis, has been implemented to combine A(1)ATVar variant information with SERPINA1 sequence and annotation data. A direct data submission tool allows registered users to submit data on novel AAT variant alleles as well as experimental protocols to explore SERPINA1 genetic heterogeneity, via a password-protected interface. Database access is free of charge and there are no registration requirements for querying the data. The A(1)ATVar database is the only integrated database on the Internet offering summarized information on AAT allelic variants and could be useful not only for clinical diagnosis and research on AAT deficiency and the SERPINA1 gene, but could also serve as an example for an all-in-one solution for locus-specific database (LSDB) development and curation.

The novel human SHOX allelic variant database

Short stature due to SHOX deficiency represents the most commonly known form of growth failure, with a frequency greater than 1:1,000 in the Caucasian population. As many different mutations can cause SHOX haploinsufficiency, a comprehensive collection of gene variants represents an essential tool to distinguish between functional variants and polymorphisms. We have created a novel and widely extended SHOX database using the "LOVD in a box-solution." This database contains not only a larger amount of mutation data (140 novel mutations were added), but also reports on phenotypic consequences, mode of inheritance, and ethnic origin, as well as on functional consequences of mutations investigated. In addition, the database now includes non-disease-related polymorphisms to enable researchers to evaluate their diagnostic findings. The database (Available at: http://hyg-serv-01.hyg.uni-heidelberg.de/lovd/index.php?select_db=SHOX; Last accessed: 12 April 2007) contains all presently known 199 intragenic mutations (SNPs as well as small deletions and insertions), 126 of which are unique. The remote user is able to search the data and to submit new mutations into the database. Furthermore, it includes general information about the SHOX gene via links to other resources such as MIM, GDB, HGMD, and HAPMAP, as well as websites of Short Stature Associations.

National and ethnic mutation databases: recording populations' genography

Genetic databases are gradually assuming an increasing importance in all areas of health care. The national and ethnic mutation databases (NEMDBs) are continuously updated mutation depositories, recording extensive information over the described genetic heterogeneity of an ethnic group or population. Together with the central and locus-specific databases, those resources not only enhance awareness of the various genetic disorders but also facilitate the provision of genetic services and provide useful insights into the genographic history of human populations. Fifteen independent NEMDBs devoted to the documentation of the extant genetic heterogeneity in various population groups within 57 different countries were assessed; 13 of the NEMDBs were fully functional. The contents of the 13 fully functional NEMDBs were thoroughly analyzed for the presence or absence of 39 criteria, pertaining database general information, operating platform, data source and submission, and querying capacity. This study provides a strong case for uniformity of data to make the NEMDBs content maximally useful. In this direction, a hypothetical content for the ideal NEMDB is derived, which is currently being incorporated in an upgraded version of the ETHNOS NEMDB development and curation software, as well as a community structure that would enhance the chances of mutation frequency capture and documentation in human populations. The ultimate goal is that interested parties and granting bodies will assist in achieving the vision of a comprehensive resource that collects and displays all population-specific genetic information discovered.

Locus-specific mutation databases: pitfalls and good practice based on the p53 experience

Between 50,000 and 60,000 mutations have been described in various genes that are associated with a wide variety of diseases. Reporting, storing and analysing these data is an important challenge as such data provide invaluable information for both clinical medicine and basic science. Locus-specific databases have been developed to exploit this huge volume of data. The p53 mutation database is a paradigm, as it constitutes the largest collection of somatic mutations (22,000). However, there are several biases in this database that can lead to serious erroneous interpretations. We describe several rules for mutation database management that could benefit the entire scientific community.

Human mutation databases

The first part of this unit compares general and locus-specific mutation databases. The second section deals with submitting data. The third part provides guidance for accessing mutation data. The final section offers advice on database construction.

Hellenic National Mutation Database: a prototype database for mutations leading to inherited disorders in the Hellenic population

The exponential discovery rate of new genomic alterations, leading to inherited disorders, as well as the need for comparative studies of different population's mutation frequencies necessitates recording their population-wide spectrum in online mutation databases. We report the construction of the Hellenic National Mutation database (http://www.goldenhelix.org/hellenic), a prototype database derived from a multicenter academic initiative, aiming to provide high quality and up-to-date information on the underlying genetic heterogeneity of inherited disorders found in the Hellenic population. Database records include informative summaries of the various genetic disorders studied in the Hellenic population, focused in particular on their incidence in Greece, a comprehensive reference list, and a well-structured query interface, which provides easy access to the list of the different mutations responsible for the inherited disorders in the Hellenic population. Also, extensive links to the respective Online Mendelian Inheritance in Man (OMIM) entries and, when available, to the locus-specific databases are provided, so that the user can retrieve the maximum amount of information from a single website. Furthermore, the Hellenic National Mutation database design allows easy data entry and curation. Creation of the Hellenic National Mutation database will significantly facilitate molecular diagnosis of inherited disorders in Greece and will motivate further investigation of yet unknown genetic diseases in the Hellenic population.

LOVD: Easy creation of a locus-specific sequence variation database using an “LSDB-in-a-box” approach

The completion of the human genome project has initiated, as well as provided the basis for, the collection and study of all sequence variation between individuals. Direct access to up-to-date information on sequence variation is currently provided most efficiently through web-based, gene-centered, locus-specific databases (LSDBs). We have developed the Leiden Open (source) Variation Database (LOVD) software approaching the "LSDB-in-a-Box" idea for the easy creation and maintenance of a fully web-based gene sequence variation database. LOVD is platform-independent and uses PHP and MySQL open source software only. The basic gene-centered and modular design of the database follows the recommendations of the Human Genome Variation Society (HGVS) and focuses on the collection and display of DNA sequence variations. With minimal effort, the LOVD platform is extendable with clinical data. The open set-up should both facilitate and promote functional extension with scripts written by the community. The LOVD software is freely available from the Leiden Muscular Dystrophy pages (www.DMD.nl/LOVD/). To promote the use of LOVD, we currently offer curators the possibility to set up an LSDB on our Leiden server.

The humanFOXL2 mutation database

Blepharophimosis-ptosis-epicanthus inversus syndrome (BPES; MIM# 110100) is an autosomal dominant genetic condition in which an eyelid malformation is associated (type I) or not associated (type II) with premature ovarian failure (POF). In 2001, mutations in the FOXL2 gene, encoding a forkhead transcription factor, were shown to cause both BPES type I and II. Since then, a number of reports have appeared that describe intragenic FOXL2 mutations in BPES patients. In addition, a few FOXL2 variants have been reported in isolated POF patients and XX males. Previously, our group has described a large number of FOXL2 mutations, thereby demonstrating the existence of two mutational hotspots in FOXL2, intra- and interfamilial phenotypic variability in BPES families, and genotype-phenotype correlations for a number of mutations in BPES patients. Here we describe a locus-specific Human FOXL2 Mutation Database (http://medgen.ugent.be/foxl2/), created using the MuStaR software. Our database contains general information about the FOXL2 gene, as well as details about 135 intragenic mutations and variants of FOXL2, obtained from published papers, abstracts of meetings, and from unpublished data produced by our group. Not included in the current version of the database are variants residing outside the coding region of FOXL2 and molecular cytogenetic rearrangements of the FOXL2 locus. The Human FOXL2 Mutation Database was created to provide a unique publicly available online resource of information about human FOXL2 mutations/variants associated with BPES and POF. It allows remote users to submit new mutations to the database and to query the database using a web form. It will facilitate evaluation of the pathogenicity of a particular mutation, as it contains data about disease-causing mutations and polymorphisms in BPES and isolated POF patients, and a link to the known FOXL2 orthologs. Moreover, it will allow us to establish more accurate genotype-phenotype correlations, since clinical information is contained in the database.

Trimethylaminuria and a human FMO3 mutation database

Trimethylaminuria (TMAuria), or fish-odor syndrome, is due to defective flavin-containing monooxygenase 3 (FMO3). In the liver, this protein catalyzes the NADPH-dependent oxidative metabolism of odorous trimethylamine (TMA), derived in the gut from dietary sources, to nonodorous trimethylamine N-oxide (TMA N-oxide). Affected individuals are unable to carry out this reaction and consequently exude a fishy body odor, due to the secretion of TMA in their breath and sweat and its excretion in their urine. This leads to a variety of psychosocial problems, including disruption of schooling, clinical depression, and attempted suicide. Twelve missense, three nonsense, and one gross deletion mutation are known to cause TMAuria. FMO3 is also a drug-metabolizing enzyme and compromised activity is expected to have implications for the efficacy of drug treatment and the possibility of adverse drug reactions both in TMAuric patients and in the general population. To date eight polymorphic variants, not associated with TMAuria, have been reported. A human FMO3 mutation database was created using MuStar, a locus-specific database system for maintaining data about allelic variants and distributing these via the World Wide Web. The database currently contains 24 entries and is accessible on the World Wide Web via the URL http://human-fmo3.biochem.ucl.ac.uk/Human_FMO3. Additional entries can be submitted via the curator of the database or via a web-based form.

The human SHOX mutation database

The human SHOX database has recently been established to provide clinicians and scientists access to a central source of information about all known SHOX mutations associated with short stature phenotypes such as idiopathic short stature, Lèri-Weill dyschondrosteosis, Langer syndrome, and Turner syndrome. So far, the database contains 29 unique intragenic mutations of the SHOX gene. These mutations were detected in a total of 39 patients from different families. Fourteen of these mutations have been found from the SHOX research group at the Institute of Human Genetics in Heidelberg, Germany; 25 mutations are from data reported in the literature. Not included in this database are complete SHOX gene deletions which represent the majority of all detectable SHOX mutations [Rappold et al., 2002]. The database is accessible via the website www.shox.uni-hd.de. It contains general information about the SHOX gene, and allows remote users to search the data and to submit new mutations to the database.

Time for a unified system of mutation description and reporting: a review of locus-specific mutation databases

Mutation databases of human genes are assuming an increasing importance in all areas of health care. In addition, more and more experts in the mutations and diseases of particular genes are curating published and unpublished mutations in locus-specific databases (LSDB). These databases contain such extensive information that they have become known as knowledge bases. We analyzed these databases and their content between June 21, 2001, and July 18, 2001. We were able to access 94 independent websites devoted to the documentation of mutation containing 262 LSDBs for study. We analyzed one LSDB from each of these websites (i.e., 94 LSDBs) for the presence or absence of 80 content criteria, as generally each gene in a multigene website documented the same criteria. No criterion studied gave unanimous agreement in every database. Twenty-two genes were represented by more than one LSDB. The number of mutations recorded, excluding p53, was 23,822 with 1518 polymorphisms. Fifty-four percent of the LSDBs studied were easy to use and 11% hard to follow; 73% of the databases were displayed through HTML. Three databases were found that were given a high score for ease of use and wealth of content. Thus, the study provided a strong case for uniformity of data to make the content maximally useful. In this direction, a hypothetical content for an ideal LSDB was derived. We also derived a community structure that would enhance the chances of mutation capture rather than being left unpublished in a patient's report. We hope the interested community and granting bodies will assist in achieving the vision of a public system that collects and displays all variants discovered.

7th International HUGO Mutation Database Meeting, October 19, 1999, San Francisco, USA

The 7th International HUGO Mutation Database Meeting was held on October 19, 1999 in conjunction with the annual meeting of the American Society of Genetics in San Fransisco, California, U.S.A. Meeting highlights are described, including discussions of topics such as the ethical aspects of variation databases, ethical guidelines which should be established immediately, data protection laws which may affect access to data, and plans to make variation databases financially self-sustaining. A resolution was passed which encourages HUGO and Mutation database Initiative (MDI) collaboration (under the name HUGO-MDI) to provide an integrated, properly funded system of variation databases.

Guidelines and recommendations for content, structure, and deployment of mutation databases: II. Journey in progress

The HUGO Mutation Database Initiative has produced guidelines and recommendations addressing uniform nomenclature of (human) genes and alleles, and computing standards to permit a moderate level of built-in redundancy, searchable interfaces, and compatibility between the comprehensive (genomic) and locus-specific types of databases. The participating community (developers and users) have been moving the project along rapidly, as described here.